chore(release): 2.8.2 [skip ci]

## [2.8.2](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.8.1...v2.8.2) (2025-10-08)

### Bug Fixes

* revert to showing only active players in room games ([87cc0b6](87cc0b64fb))

.claude/terminology.md

@@ -0,0 +1,57 @@
+# Soroban Abacus Flashcards - Terminology Reference
+
+## User vs Player vs Room Member
+
+**CRITICAL**: Do not confuse these three concepts!
+
+### Quick Reference
+
+- **USER** = Identity/account (one per person, identified by `guestId` cookie)
+- **PLAYER** = Game avatar/profile (multiple per user, from `players` table)
+- **ROOM MEMBER** = USER's participation in a multiplayer room
+
+### Key Rule
+
+**When a USER joins a room, their ACTIVE PLAYERS join the game.**
+
+Example:
+- USER "Jane" has 3 players: Alice, Bob, Charlie
+- Alice and Bob are active (`isActive: true`)
+- When Jane joins a room, Alice and Bob participate in the game
+- The `arcade_sessions.activePlayers` array contains `[alice_id, bob_id]`
+
+### Database Schema
+
+```
+users (identity)
+  ├─ players (avatars/profiles) - where isActive = true
+  └─ room_members (room participation)
+
+arcade_sessions
+  ├─ userId: references users.id
+  ├─ activePlayers: Array<player.id> ← PLAYER IDs, not USER IDs!
+  └─ roomId: references arcade_rooms.id
+```
+
+### Common Mistakes to Avoid
+
+❌ Using USER ID in `activePlayers` - should be PLAYER IDs
+❌ Assuming one USER = one PLAYER - users can have multiple players
+❌ Tracking game moves/scores by USER - should track by PLAYER
+❌ Confusing room_members.displayName with players.name - different concepts
+
+### Full Documentation
+
+See: `docs/terminology-user-player-room.md` for complete explanation with examples.
+
+## Other Project-Specific Terms
+
+### Arcade vs Games
+
+- **`/games/*`** - Single player or local multiplayer (same device)
+- **`/arcade/*`** - Online multiplayer with sessions and rooms
+
+### Session Types
+
+- **Solo Session**: `arcade_sessions.roomId = null`, user playing alone
+- **Room Session**: `arcade_sessions.roomId = room_xyz`, shared game state across room members

CHANGELOG.md

@@ -1,3 +1,141 @@
+## [2.8.2](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.8.1...v2.8.2) (2025-10-08)
+
+
+### Bug Fixes
+
+* revert to showing only active players in room games ([87cc0b6](https://github.com/antialias/soroban-abacus-flashcards/commit/87cc0b64fb5f3debaf1d2f122aecfefc62922fed))
+
+## [2.8.1](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.8.0...v2.8.1) (2025-10-08)
+
+
+### Bug Fixes
+
+* include all players from room members in room games ([28a2e7d](https://github.com/antialias/soroban-abacus-flashcards/commit/28a2e7d6511e70b83adf7d0465789a91026bc1f7))
+
+## [2.8.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.7.4...v2.8.0) (2025-10-08)
+
+
+### Features
+
+* implement room-wide multi-user game state synchronization ([8175c43](https://github.com/antialias/soroban-abacus-flashcards/commit/8175c43533c474fff48eb128c97747033bfb434a))
+
+
+### Tests
+
+* add comprehensive tests for arcade guard and room navigation ([b49630f](https://github.com/antialias/soroban-abacus-flashcards/commit/b49630f3cb02ebbac75b4680948bbface314dccb))
+
+## [2.7.4](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.7.3...v2.7.4) (2025-10-08)
+
+
+### Bug Fixes
+
+* respect enabled flag in useArcadeGuard WebSocket redirects ([01ff114](https://github.com/antialias/soroban-abacus-flashcards/commit/01ff114258ff7ab43ef2bd79b41c7035fe02ac70))
+
+
+### Code Refactoring
+
+* move room management pages to /arcade-rooms ([4316687](https://github.com/antialias/soroban-abacus-flashcards/commit/431668729cfb145d6e0c13947de2a82f27fa400d))
+
+## [2.7.3](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.7.2...v2.7.3) (2025-10-08)
+
+
+### Bug Fixes
+
+* set room sessions to use /arcade/room URL ([9dac431](https://github.com/antialias/soroban-abacus-flashcards/commit/9dac431c1f91c246f67a059cda3cff6cbef40a43))
+
+## [2.7.2](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.7.1...v2.7.2) (2025-10-08)
+
+
+### Bug Fixes
+
+* add hasAttemptedFetch flag to prevent premature redirect ([c30f585](https://github.com/antialias/soroban-abacus-flashcards/commit/c30f58581028878350282cad5231d614590d9f2b))
+
+## [2.7.1](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.7.0...v2.7.1) (2025-10-08)
+
+
+### Bug Fixes
+
+* resolve race condition in /arcade/room redirect ([5ed2ab2](https://github.com/antialias/soroban-abacus-flashcards/commit/5ed2ab21cab408147081a493c8dd6b1de48b2d01))
+
+## [2.7.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.6.0...v2.7.0) (2025-10-08)
+
+
+### Features
+
+* extend GameModeContext to support room-based multiplayer ([ee6094d](https://github.com/antialias/soroban-abacus-flashcards/commit/ee6094d59d26a9e80ba5d023ca6dc13143bea308))
+
+## [2.6.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.5.0...v2.6.0) (2025-10-08)
+
+
+### Features
+
+* refactor room addressing to /arcade/room ([e7d2a73](https://github.com/antialias/soroban-abacus-flashcards/commit/e7d2a73ddf2048691325a18e3d71a7ece444c131))
+
+## [2.5.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.4.6...v2.5.0) (2025-10-08)
+
+
+### Features
+
+* display room info and network players in mini app nav ([5e3261f](https://github.com/antialias/soroban-abacus-flashcards/commit/5e3261f3bec8c19ec88c9a35a7e6ef8eda88a55e))
+
+## [2.4.6](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.4.5...v2.4.6) (2025-10-08)
+
+
+### Bug Fixes
+
+* real-time room member updates via globalThis socket.io sharing ([94a1d9b](https://github.com/antialias/soroban-abacus-flashcards/commit/94a1d9b11058bfb4b54a4753e143cf85f215e913))
+
+## [2.4.5](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.4.4...v2.4.5) (2025-10-08)
+
+
+### Bug Fixes
+
+* send all members (not just online) in socket broadcasts ([3fa6cce](https://github.com/antialias/soroban-abacus-flashcards/commit/3fa6cce17a7acd940cf5a9e6433bf6c4b497540c))
+
+## [2.4.4](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.4.3...v2.4.4) (2025-10-08)
+
+
+### Bug Fixes
+
+* correctly access getSocketIO from dynamic import ([30abf33](https://github.com/antialias/soroban-abacus-flashcards/commit/30abf33ee86b36f2a98014e5b017fa8e466a2107))
+
+## [2.4.3](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.4.2...v2.4.3) (2025-10-08)
+
+
+### Bug Fixes
+
+* resolve socket-server import path for Next.js build ([12c3c37](https://github.com/antialias/soroban-abacus-flashcards/commit/12c3c37ff8e1d3df71d72e527c08fa975043c504))
+
+## [2.4.2](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.4.1...v2.4.2) (2025-10-08)
+
+
+### Bug Fixes
+
+* broadcast member join/leave events immediately via API ([ebfc88c](https://github.com/antialias/soroban-abacus-flashcards/commit/ebfc88c5ea0a8a0fdda039fa129e1054b9c42e65))
+
+## [2.4.1](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.4.0...v2.4.1) (2025-10-08)
+
+
+### Bug Fixes
+
+* make leave room button actually remove user from room ([49f12f8](https://github.com/antialias/soroban-abacus-flashcards/commit/49f12f8cab631fedd33f1bc09febfdc95e444625))
+
+## [2.4.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.3.1...v2.4.0) (2025-10-08)
+
+
+### Features
+
+* add arcade room/session info and network players to nav ([6800747](https://github.com/antialias/soroban-abacus-flashcards/commit/6800747f80a29c91ba0311a8330d594c1074097d))
+* add real-time WebSocket updates for room membership ([7ebb2be](https://github.com/antialias/soroban-abacus-flashcards/commit/7ebb2be3927762a5fe9b6fb7fb15d6b88abb7b6a))
+* implement modal room enforcement (one room per user) ([f005fbb](https://github.com/antialias/soroban-abacus-flashcards/commit/f005fbbb773f4d250b80d71593490976af82d5a5))
+* improve room navigation and membership UI ([bc219c2](https://github.com/antialias/soroban-abacus-flashcards/commit/bc219c2ad66707f03e7a6cf587b9d190c736e26d))
+
+
+### Bug Fixes
+
+* auto-cleanup orphaned arcade sessions without valid rooms ([3c002ab](https://github.com/antialias/soroban-abacus-flashcards/commit/3c002ab29d1b72a0e1ffb70bb0744dc560e7bdc2))
+* show correct join/leave button based on room membership ([5751dfe](https://github.com/antialias/soroban-abacus-flashcards/commit/5751dfef5c81981937cd5300c4256e5b74bb7488))
+
 ## [2.3.1](https://github.com/antialias/soroban-abacus-flashcards/compare/v2.3.0...v2.3.1) (2025-10-07)
 
 

apps/web/.claude/settings.local.json

@@ -1,37 +1,6 @@
 {
   "permissions": {
-    "allow": [
-      "Bash(npm run build:*)",
-      "Bash(npx tsc:*)",
-      "Bash(curl:*)",
-      "Bash(git add:*)",
-      "Bash(git commit -m \"$(cat <<''EOF''\nfix: lazy-load database connection to prevent build-time access\n\nRefactor db/index.ts to use lazy initialization via Proxy pattern.\nThis prevents the database from being accessed at module import time,\nwhich was causing Next.js build failures in CI/CD environments where\nno database file exists.\n\nThe database connection is now created only when first accessed at\nruntime, allowing static site generation to complete successfully.\n\n🤖 Generated with [Claude Code](https://claude.com/claude-code)\n\nCo-Authored-By: Claude <noreply@anthropic.com>\nEOF\n)\")",
-      "Bash(git push:*)",
-      "Read(//Users/antialias/projects/soroban-abacus-flashcards/**)",
-      "Bash(npm install:*)",
-      "Bash(cat:*)",
-      "Bash(pnpm add:*)",
-      "Bash(npx biome check:*)",
-      "Bash(npx:*)",
-      "Bash(eslint:*)",
-      "Bash(npm run lint:fix:*)",
-      "Bash(npm run format:*)",
-      "Bash(npm run lint:*)",
-      "Bash(pnpm install:*)",
-      "Bash(pnpm run:*)",
-      "Bash(rm:*)",
-      "Bash(lsof:*)",
-      "Bash(xargs kill:*)",
-      "Bash(tee:*)",
-      "Bash(for file in src/app/arcade/complement-race/components/RaceTrack/CircularTrack.tsx src/app/arcade/complement-race/components/RaceTrack/LinearTrack.tsx src/app/games/complement-race/components/RaceTrack/CircularTrack.tsx src/app/games/complement-race/components/RaceTrack/LinearTrack.tsx)",
-      "Bash(do)",
-      "Bash(done)",
-      "Bash(for file in src/app/arcade/complement-race/components/RaceTrack/SteamTrainJourney.tsx src/app/games/complement-race/components/RaceTrack/SteamTrainJourney.tsx)",
-      "Bash(for file in src/app/arcade/complement-race/hooks/useTrackManagement.ts src/app/games/complement-race/hooks/useTrackManagement.ts)",
-      "Bash(echo \"EXIT CODE: $?\")",
-      "Bash(git commit -m \"$(cat <<''EOF''\nfeat: add Biome + ESLint linting setup\n\nAdd Biome for formatting and general linting, with minimal ESLint\nconfiguration for React Hooks rules only. This provides:\n\n- Fast formatting via Biome (10-100x faster than Prettier)\n- General JS/TS linting via Biome\n- React Hooks validation via ESLint (rules-of-hooks)\n- Import organization via Biome\n\nConfiguration files:\n- biome.jsonc: Biome config with custom rule overrides\n- eslint.config.js: Minimal flat config for React Hooks only\n- .gitignore: Added Biome cache exclusion\n- LINTING.md: Documentation for the setup\n\nScripts added to package.json:\n- npm run lint: Check all files\n- npm run lint:fix: Auto-fix issues\n- npm run format: Format all files\n- npm run check: Full Biome check\n\n🤖 Generated with [Claude Code](https://claude.com/claude-code)\n\nCo-Authored-By: Claude <noreply@anthropic.com>\nEOF\n)\")",
-      "Bash(git commit:*)"
-    ],
+    "allow": ["Bash(npm test:*)"],
     "deny": [],
     "ask": []
   }

apps/web/__tests__/api-arcade-rooms.e2e.test.ts

@@ -0,0 +1,455 @@
+/**
+ * @vitest-environment node
+ */
+
+import { eq } from 'drizzle-orm'
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { db, schema } from '../src/db'
+import { createRoom } from '../src/lib/arcade/room-manager'
+import { addRoomMember } from '../src/lib/arcade/room-membership'
+
+/**
+ * Arcade Rooms API E2E Tests
+ *
+ * Tests the full arcade room system:
+ * - Room CRUD operations
+ * - Member management
+ * - Access control
+ * - Room code lookups
+ */
+
+describe('Arcade Rooms API', () => {
+  let testUserId1: string
+  let testUserId2: string
+  let testGuestId1: string
+  let testGuestId2: string
+  let testRoomId: string
+
+  beforeEach(async () => {
+    // Create test users
+    testGuestId1 = `test-guest-${Date.now()}-${Math.random().toString(36).slice(2)}`
+    testGuestId2 = `test-guest-${Date.now()}-${Math.random().toString(36).slice(2)}`
+
+    const [user1] = await db.insert(schema.users).values({ guestId: testGuestId1 }).returning()
+    const [user2] = await db.insert(schema.users).values({ guestId: testGuestId2 }).returning()
+
+    testUserId1 = user1.id
+    testUserId2 = user2.id
+  })
+
+  afterEach(async () => {
+    // Clean up rooms (cascade deletes members)
+    if (testRoomId) {
+      await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, testRoomId))
+    }
+
+    // Clean up users
+    await db.delete(schema.users).where(eq(schema.users.id, testUserId1))
+    await db.delete(schema.users).where(eq(schema.users.id, testUserId2))
+  })
+
+  describe('Room Creation', () => {
+    it('creates a room with valid data', async () => {
+      const room = await createRoom({
+        name: 'Test Room',
+        createdBy: testGuestId1,
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: { difficulty: 6 },
+      })
+
+      testRoomId = room.id
+
+      expect(room).toBeDefined()
+      expect(room.name).toBe('Test Room')
+      expect(room.createdBy).toBe(testGuestId1)
+      expect(room.gameName).toBe('matching')
+      expect(room.status).toBe('lobby')
+      expect(room.isLocked).toBe(false)
+      expect(room.ttlMinutes).toBe(60)
+      expect(room.code).toMatch(/^[A-Z0-9]{6}$/)
+    })
+
+    it('creates room with custom TTL', async () => {
+      const room = await createRoom({
+        name: 'Custom TTL Room',
+        createdBy: testGuestId1,
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: {},
+        ttlMinutes: 120,
+      })
+
+      testRoomId = room.id
+
+      expect(room.ttlMinutes).toBe(120)
+    })
+
+    it('generates unique room codes', async () => {
+      const room1 = await createRoom({
+        name: 'Room 1',
+        createdBy: testGuestId1,
+        creatorName: 'User 1',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+
+      const room2 = await createRoom({
+        name: 'Room 2',
+        createdBy: testGuestId2,
+        creatorName: 'User 2',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+
+      // Clean up both rooms
+      testRoomId = room1.id
+      await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, room2.id))
+
+      expect(room1.code).not.toBe(room2.code)
+    })
+  })
+
+  describe('Room Retrieval', () => {
+    beforeEach(async () => {
+      // Create a test room
+      const room = await createRoom({
+        name: 'Retrieval Test Room',
+        createdBy: testGuestId1,
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+      testRoomId = room.id
+    })
+
+    it('retrieves room by ID', async () => {
+      const room = await db.query.arcadeRooms.findFirst({
+        where: eq(schema.arcadeRooms.id, testRoomId),
+      })
+
+      expect(room).toBeDefined()
+      expect(room?.id).toBe(testRoomId)
+      expect(room?.name).toBe('Retrieval Test Room')
+    })
+
+    it('retrieves room by code', async () => {
+      const createdRoom = await db.query.arcadeRooms.findFirst({
+        where: eq(schema.arcadeRooms.id, testRoomId),
+      })
+
+      const room = await db.query.arcadeRooms.findFirst({
+        where: eq(schema.arcadeRooms.code, createdRoom!.code),
+      })
+
+      expect(room).toBeDefined()
+      expect(room?.id).toBe(testRoomId)
+    })
+
+    it('returns undefined for non-existent room', async () => {
+      const room = await db.query.arcadeRooms.findFirst({
+        where: eq(schema.arcadeRooms.id, 'nonexistent-room-id'),
+      })
+
+      expect(room).toBeUndefined()
+    })
+  })
+
+  describe('Room Updates', () => {
+    beforeEach(async () => {
+      const room = await createRoom({
+        name: 'Update Test Room',
+        createdBy: testGuestId1,
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+      testRoomId = room.id
+    })
+
+    it('updates room name', async () => {
+      const [updated] = await db
+        .update(schema.arcadeRooms)
+        .set({ name: 'Updated Name' })
+        .where(eq(schema.arcadeRooms.id, testRoomId))
+        .returning()
+
+      expect(updated.name).toBe('Updated Name')
+    })
+
+    it('locks room', async () => {
+      const [updated] = await db
+        .update(schema.arcadeRooms)
+        .set({ isLocked: true })
+        .where(eq(schema.arcadeRooms.id, testRoomId))
+        .returning()
+
+      expect(updated.isLocked).toBe(true)
+    })
+
+    it('updates room status', async () => {
+      const [updated] = await db
+        .update(schema.arcadeRooms)
+        .set({ status: 'playing' })
+        .where(eq(schema.arcadeRooms.id, testRoomId))
+        .returning()
+
+      expect(updated.status).toBe('playing')
+    })
+
+    it('updates lastActivity on any change', async () => {
+      const originalRoom = await db.query.arcadeRooms.findFirst({
+        where: eq(schema.arcadeRooms.id, testRoomId),
+      })
+
+      // Wait a bit to ensure different timestamp (at least 1 second for SQLite timestamp resolution)
+      await new Promise((resolve) => setTimeout(resolve, 1100))
+
+      const [updated] = await db
+        .update(schema.arcadeRooms)
+        .set({ name: 'Activity Test', lastActivity: new Date() })
+        .where(eq(schema.arcadeRooms.id, testRoomId))
+        .returning()
+
+      expect(updated.lastActivity.getTime()).toBeGreaterThan(originalRoom!.lastActivity.getTime())
+    })
+  })
+
+  describe('Room Deletion', () => {
+    it('deletes room', async () => {
+      const room = await createRoom({
+        name: 'Delete Test Room',
+        createdBy: testGuestId1,
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+
+      await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, room.id))
+
+      const deleted = await db.query.arcadeRooms.findFirst({
+        where: eq(schema.arcadeRooms.id, room.id),
+      })
+
+      expect(deleted).toBeUndefined()
+    })
+
+    it('cascades delete to room members', async () => {
+      const room = await createRoom({
+        name: 'Cascade Test Room',
+        createdBy: testGuestId1,
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+
+      // Add member
+      await addRoomMember({
+        roomId: room.id,
+        userId: testGuestId1,
+        displayName: 'Test User',
+      })
+
+      // Verify member exists
+      const membersBefore = await db.query.roomMembers.findMany({
+        where: eq(schema.roomMembers.roomId, room.id),
+      })
+      expect(membersBefore).toHaveLength(1)
+
+      // Delete room
+      await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, room.id))
+
+      // Verify members deleted
+      const membersAfter = await db.query.roomMembers.findMany({
+        where: eq(schema.roomMembers.roomId, room.id),
+      })
+      expect(membersAfter).toHaveLength(0)
+    })
+  })
+
+  describe('Room Members', () => {
+    beforeEach(async () => {
+      const room = await createRoom({
+        name: 'Members Test Room',
+        createdBy: testGuestId1,
+        creatorName: 'Test User 1',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+      testRoomId = room.id
+    })
+
+    it('adds member to room', async () => {
+      const result = await addRoomMember({
+        roomId: testRoomId,
+        userId: testGuestId1,
+        displayName: 'Test User 1',
+        isCreator: true,
+      })
+
+      expect(result.member).toBeDefined()
+      expect(result.member.roomId).toBe(testRoomId)
+      expect(result.member.userId).toBe(testGuestId1)
+      expect(result.member.displayName).toBe('Test User 1')
+      expect(result.member.isCreator).toBe(true)
+      expect(result.member.isOnline).toBe(true)
+    })
+
+    it('adds multiple members to room', async () => {
+      await addRoomMember({
+        roomId: testRoomId,
+        userId: testGuestId1,
+        displayName: 'User 1',
+      })
+
+      await addRoomMember({
+        roomId: testRoomId,
+        userId: testGuestId2,
+        displayName: 'User 2',
+      })
+
+      const members = await db.query.roomMembers.findMany({
+        where: eq(schema.roomMembers.roomId, testRoomId),
+      })
+
+      expect(members).toHaveLength(2)
+    })
+
+    it('updates existing member instead of creating duplicate', async () => {
+      // Add member first time
+      await addRoomMember({
+        roomId: testRoomId,
+        userId: testGuestId1,
+        displayName: 'First Time',
+      })
+
+      // Add same member again
+      await addRoomMember({
+        roomId: testRoomId,
+        userId: testGuestId1,
+        displayName: 'Second Time',
+      })
+
+      const members = await db.query.roomMembers.findMany({
+        where: eq(schema.roomMembers.roomId, testRoomId),
+      })
+
+      // Should still only have 1 member
+      expect(members).toHaveLength(1)
+    })
+
+    it('removes member from room', async () => {
+      const result = await addRoomMember({
+        roomId: testRoomId,
+        userId: testGuestId1,
+        displayName: 'Test User',
+      })
+
+      await db.delete(schema.roomMembers).where(eq(schema.roomMembers.id, result.member.id))
+
+      const members = await db.query.roomMembers.findMany({
+        where: eq(schema.roomMembers.roomId, testRoomId),
+      })
+
+      expect(members).toHaveLength(0)
+    })
+
+    it('tracks online status', async () => {
+      const result = await addRoomMember({
+        roomId: testRoomId,
+        userId: testGuestId1,
+        displayName: 'Test User',
+      })
+
+      expect(result.member.isOnline).toBe(true)
+
+      // Set offline
+      const [updated] = await db
+        .update(schema.roomMembers)
+        .set({ isOnline: false })
+        .where(eq(schema.roomMembers.id, result.member.id))
+        .returning()
+
+      expect(updated.isOnline).toBe(false)
+    })
+  })
+
+  describe('Access Control', () => {
+    beforeEach(async () => {
+      const room = await createRoom({
+        name: 'Access Test Room',
+        createdBy: testGuestId1,
+        creatorName: 'Creator',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+      testRoomId = room.id
+    })
+
+    it('identifies room creator correctly', async () => {
+      const room = await db.query.arcadeRooms.findFirst({
+        where: eq(schema.arcadeRooms.id, testRoomId),
+      })
+
+      expect(room?.createdBy).toBe(testGuestId1)
+    })
+
+    it('distinguishes creator from other users', async () => {
+      const room = await db.query.arcadeRooms.findFirst({
+        where: eq(schema.arcadeRooms.id, testRoomId),
+      })
+
+      expect(room?.createdBy).not.toBe(testGuestId2)
+    })
+  })
+
+  describe('Room Listing', () => {
+    beforeEach(async () => {
+      // Create multiple test rooms
+      const room1 = await createRoom({
+        name: 'Matching Room',
+        createdBy: testGuestId1,
+        creatorName: 'User 1',
+        gameName: 'matching',
+        gameConfig: {},
+      })
+
+      const room2 = await createRoom({
+        name: 'Memory Quiz Room',
+        createdBy: testGuestId2,
+        creatorName: 'User 2',
+        gameName: 'memory-quiz',
+        gameConfig: {},
+      })
+
+      testRoomId = room1.id
+
+      // Clean up room2 after test
+      afterEach(async () => {
+        await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, room2.id))
+      })
+    })
+
+    it('lists all active rooms', async () => {
+      const rooms = await db.query.arcadeRooms.findMany({
+        where: eq(schema.arcadeRooms.status, 'lobby'),
+      })
+
+      expect(rooms.length).toBeGreaterThanOrEqual(2)
+    })
+
+    it('excludes locked rooms from listing', async () => {
+      // Lock one room
+      await db
+        .update(schema.arcadeRooms)
+        .set({ isLocked: true })
+        .where(eq(schema.arcadeRooms.id, testRoomId))
+
+      const unlockedRooms = await db.query.arcadeRooms.findMany({
+        where: eq(schema.arcadeRooms.isLocked, false),
+      })
+
+      expect(unlockedRooms.every((r) => !r.isLocked)).toBe(true)
+    })
+  })
+})

apps/web/__tests__/middleware.e2e.test.ts

@@ -76,7 +76,7 @@ describe('Middleware E2E', () => {
     const originalEnv = process.env.NODE_ENV
     Object.defineProperty(process.env, 'NODE_ENV', {
       value: 'production',
-      configurable: true
+      configurable: true,
     })
 
     const req = new NextRequest('http://localhost:3000/')
@@ -87,7 +87,7 @@ describe('Middleware E2E', () => {
 
     Object.defineProperty(process.env, 'NODE_ENV', {
       value: originalEnv,
-      configurable: true
+      configurable: true,
     })
   })
 
@@ -95,7 +95,7 @@ describe('Middleware E2E', () => {
     const originalEnv = process.env.NODE_ENV
     Object.defineProperty(process.env, 'NODE_ENV', {
       value: 'development',
-      configurable: true
+      configurable: true,
     })
 
     const req = new NextRequest('http://localhost:3000/')
@@ -106,7 +106,7 @@ describe('Middleware E2E', () => {
 
     Object.defineProperty(process.env, 'NODE_ENV', {
       value: originalEnv,
-      configurable: true
+      configurable: true,
     })
   })
 

apps/web/__tests__/orphaned-session.e2e.test.ts

@@ -0,0 +1,203 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { eq } from 'drizzle-orm'
+import { db, schema } from '../src/db'
+import { createArcadeSession, getArcadeSession } from '../src/lib/arcade/session-manager'
+import { cleanupExpiredRooms, createRoom } from '../src/lib/arcade/room-manager'
+
+/**
+ * E2E Test: Orphaned Session After Room TTL Deletion
+ *
+ * This test simulates the exact scenario reported by the user:
+ * 1. User creates a game session in a room
+ * 2. Room expires via TTL cleanup
+ * 3. User navigates to /arcade
+ * 4. System should NOT redirect to the orphaned game
+ * 5. User should see the arcade lobby normally
+ */
+describe('E2E: Orphaned Session Cleanup on Navigation', () => {
+  const testUserId = 'e2e-user-id'
+  const testGuestId = 'e2e-guest-id'
+  let testRoomId: string
+
+  beforeEach(async () => {
+    // Create test user (simulating new or returning visitor)
+    await db
+      .insert(schema.users)
+      .values({
+        id: testUserId,
+        guestId: testGuestId,
+        createdAt: new Date(),
+      })
+      .onConflictDoNothing()
+  })
+
+  afterEach(async () => {
+    // Clean up test data
+    await db.delete(schema.arcadeSessions).where(eq(schema.arcadeSessions.userId, testUserId))
+    await db.delete(schema.users).where(eq(schema.users.id, testUserId))
+    if (testRoomId) {
+      try {
+        await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, testRoomId))
+      } catch {
+        // Room may already be deleted
+      }
+    }
+  })
+
+  it('should not redirect user to orphaned game after room TTL cleanup', async () => {
+    // === SETUP PHASE ===
+    // User creates or joins a room
+    const room = await createRoom({
+      name: 'My Game Room',
+      createdBy: testGuestId,
+      creatorName: 'Test Player',
+      gameName: 'matching',
+      gameConfig: { difficulty: 6, gameType: 'abacus-numeral', turnTimer: 30 },
+      ttlMinutes: 1, // Short TTL for testing
+    })
+    testRoomId = room.id
+
+    // User starts a game session
+    const session = await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: {
+        gamePhase: 'playing',
+        cards: [],
+        gameCards: [],
+        flippedCards: [],
+        matchedPairs: 0,
+        totalPairs: 6,
+        currentPlayer: 'player-1',
+        difficulty: 6,
+        gameType: 'abacus-numeral',
+        turnTimer: 30,
+      },
+      activePlayers: ['player-1'],
+      roomId: room.id,
+    })
+
+    // Verify session was created
+    expect(session).toBeDefined()
+    expect(session.roomId).toBe(room.id)
+
+    // === TTL EXPIRATION PHASE ===
+    // Simulate time passing - room's TTL expires
+    // Set lastActivity to past so cleanup detects it
+    await db
+      .update(schema.arcadeRooms)
+      .set({
+        lastActivity: new Date(Date.now() - 2 * 60 * 1000), // 2 minutes ago
+      })
+      .where(eq(schema.arcadeRooms.id, room.id))
+
+    // Run cleanup (simulating background cleanup job)
+    const deletedCount = await cleanupExpiredRooms()
+    expect(deletedCount).toBeGreaterThan(0) // Room should be deleted
+
+    // === USER NAVIGATION PHASE ===
+    // User navigates to /arcade (arcade lobby)
+    // The useArcadeRedirect hook calls getArcadeSession to check for active session
+    const activeSession = await getArcadeSession(testGuestId)
+
+    // === ASSERTION PHASE ===
+    // Expected behavior: NO active session returned
+    // This prevents redirect to /arcade/matching which would be broken
+    expect(activeSession).toBeUndefined()
+
+    // Verify the orphaned session was cleaned up from database
+    const [orphanedSessionCheck] = await db
+      .select()
+      .from(schema.arcadeSessions)
+      .where(eq(schema.arcadeSessions.userId, testUserId))
+      .limit(1)
+
+    expect(orphanedSessionCheck).toBeUndefined()
+  })
+
+  it('should allow user to start new game after orphaned session cleanup', async () => {
+    // === SETUP: Create and orphan a session ===
+    const oldRoom = await createRoom({
+      name: 'Old Room',
+      createdBy: testGuestId,
+      creatorName: 'Test Player',
+      gameName: 'matching',
+      gameConfig: { difficulty: 6 },
+      ttlMinutes: 1,
+    })
+
+    await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: { gamePhase: 'setup' },
+      activePlayers: ['player-1'],
+      roomId: oldRoom.id,
+    })
+
+    // Delete room (TTL cleanup)
+    await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, oldRoom.id))
+
+    // === ACTION: User tries to access arcade ===
+    const orphanedSession = await getArcadeSession(testGuestId)
+    expect(orphanedSession).toBeUndefined() // Orphan cleaned up
+
+    // === ACTION: User creates new room and session ===
+    const newRoom = await createRoom({
+      name: 'New Room',
+      createdBy: testGuestId,
+      creatorName: 'Test Player',
+      gameName: 'matching',
+      gameConfig: { difficulty: 8 },
+      ttlMinutes: 60,
+    })
+    testRoomId = newRoom.id
+
+    const newSession = await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: { gamePhase: 'setup' },
+      activePlayers: ['player-1', 'player-2'],
+      roomId: newRoom.id,
+    })
+
+    // === ASSERTION: New session works correctly ===
+    expect(newSession).toBeDefined()
+    expect(newSession.roomId).toBe(newRoom.id)
+
+    const activeSession = await getArcadeSession(testGuestId)
+    expect(activeSession).toBeDefined()
+    expect(activeSession?.roomId).toBe(newRoom.id)
+  })
+
+  it('should handle race condition: getArcadeSession called while room is being deleted', async () => {
+    // Create room and session
+    const room = await createRoom({
+      name: 'Race Condition Room',
+      createdBy: testGuestId,
+      creatorName: 'Test Player',
+      gameName: 'matching',
+      gameConfig: { difficulty: 6 },
+      ttlMinutes: 60,
+    })
+    testRoomId = room.id
+
+    await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: { gamePhase: 'setup' },
+      activePlayers: ['player-1'],
+      roomId: room.id,
+    })
+
+    // Simulate race: delete room while getArcadeSession is checking
+    await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, room.id))
+
+    // Should gracefully handle and return undefined
+    const result = await getArcadeSession(testGuestId)
+    expect(result).toBeUndefined()
+  })
+})

apps/web/__tests__/room-realtime-updates.e2e.test.ts

@@ -0,0 +1,371 @@
+/**
+ * @vitest-environment node
+ */
+
+import { createServer } from 'http'
+import { eq } from 'drizzle-orm'
+import { io as ioClient, type Socket } from 'socket.io-client'
+import { afterEach, beforeEach, describe, expect, it, afterAll, beforeAll } from 'vitest'
+import { db, schema } from '../src/db'
+import { createRoom } from '../src/lib/arcade/room-manager'
+import { addRoomMember } from '../src/lib/arcade/room-membership'
+import { initializeSocketServer } from '../socket-server'
+import type { Server as SocketIOServerType } from 'socket.io'
+
+/**
+ * Real-time Room Updates E2E Tests
+ *
+ * Tests that socket broadcasts work correctly when users join/leave rooms.
+ * Simulates multiple connected users and verifies they receive real-time updates.
+ */
+
+describe('Room Real-time Updates', () => {
+  let testUserId1: string
+  let testUserId2: string
+  let testGuestId1: string
+  let testGuestId2: string
+  let testRoomId: string
+  let socket1: Socket
+  let httpServer: any
+  let io: SocketIOServerType
+  let serverPort: number
+
+  beforeAll(async () => {
+    // Create HTTP server and initialize Socket.IO for testing
+    httpServer = createServer()
+    io = initializeSocketServer(httpServer)
+
+    // Find an available port
+    await new Promise<void>((resolve) => {
+      httpServer.listen(0, () => {
+        serverPort = (httpServer.address() as any).port
+        console.log(`Test socket server listening on port ${serverPort}`)
+        resolve()
+      })
+    })
+  })
+
+  afterAll(async () => {
+    // Close all socket connections
+    if (io) {
+      io.close()
+    }
+    if (httpServer) {
+      await new Promise<void>((resolve) => {
+        httpServer.close(() => resolve())
+      })
+    }
+  })
+
+  beforeEach(async () => {
+    // Create test users
+    testGuestId1 = `test-guest-${Date.now()}-${Math.random().toString(36).slice(2)}`
+    testGuestId2 = `test-guest-${Date.now()}-${Math.random().toString(36).slice(2)}`
+
+    const [user1] = await db.insert(schema.users).values({ guestId: testGuestId1 }).returning()
+    const [user2] = await db.insert(schema.users).values({ guestId: testGuestId2 }).returning()
+
+    testUserId1 = user1.id
+    testUserId2 = user2.id
+
+    // Create a test room
+    const room = await createRoom({
+      name: 'Realtime Test Room',
+      createdBy: testGuestId1,
+      creatorName: 'User 1',
+      gameName: 'matching',
+      gameConfig: { difficulty: 6 },
+      ttlMinutes: 60,
+    })
+    testRoomId = room.id
+  })
+
+  afterEach(async () => {
+    // Disconnect sockets
+    if (socket1?.connected) {
+      socket1.disconnect()
+    }
+
+    // Clean up room members
+    await db.delete(schema.roomMembers).where(eq(schema.roomMembers.roomId, testRoomId))
+
+    // Clean up rooms
+    if (testRoomId) {
+      await db.delete(schema.arcadeRooms).where(eq(schema.arcadeRooms.id, testRoomId))
+    }
+
+    // Clean up users
+    await db.delete(schema.users).where(eq(schema.users.id, testUserId1))
+    await db.delete(schema.users).where(eq(schema.users.id, testUserId2))
+  })
+
+  it('should broadcast member-joined when a user joins via API', async () => {
+    // User 1 joins the room via API first (this is what happens when they click "Join Room")
+    await addRoomMember({
+      roomId: testRoomId,
+      userId: testGuestId1,
+      displayName: 'User 1',
+      isCreator: false,
+    })
+
+    // User 1 connects to socket
+    socket1 = ioClient(`http://localhost:${serverPort}`, {
+      path: '/api/socket',
+      transports: ['websocket'],
+    })
+
+    // Wait for socket to connect
+    await new Promise<void>((resolve, reject) => {
+      socket1.on('connect', () => resolve())
+      socket1.on('connect_error', (err) => reject(err))
+      setTimeout(() => reject(new Error('Connection timeout')), 2000)
+    })
+
+    // Small delay to ensure event handlers are set up
+    await new Promise((resolve) => setTimeout(resolve, 50))
+
+    // Set up listener for room-joined BEFORE emitting
+    const roomJoinedPromise = new Promise<void>((resolve, reject) => {
+      socket1.on('room-joined', () => resolve())
+      socket1.on('room-error', (err) => reject(new Error(err.error)))
+      setTimeout(() => reject(new Error('Room-joined timeout')), 3000)
+    })
+
+    // Now emit the join-room event
+    socket1.emit('join-room', { roomId: testRoomId, userId: testGuestId1 })
+
+    // Wait for confirmation
+    await roomJoinedPromise
+
+    // Set up listener for member-joined event BEFORE User 2 joins
+    const memberJoinedPromise = new Promise<any>((resolve, reject) => {
+      socket1.on('member-joined', (data) => {
+        resolve(data)
+      })
+      setTimeout(() => reject(new Error('Timeout waiting for member-joined event')), 3000)
+    })
+
+    // User 2 joins the room via addRoomMember
+    const { member: newMember } = await addRoomMember({
+      roomId: testRoomId,
+      userId: testGuestId2,
+      displayName: 'User 2',
+      isCreator: false,
+    })
+
+    // Manually trigger the broadcast (this is what the API route SHOULD do)
+    const { getRoomMembers } = await import('../src/lib/arcade/room-membership')
+    const { getRoomActivePlayers } = await import('../src/lib/arcade/player-manager')
+
+    const members = await getRoomMembers(testRoomId)
+    const memberPlayers = await getRoomActivePlayers(testRoomId)
+
+    const memberPlayersObj: Record<string, any[]> = {}
+    for (const [uid, players] of memberPlayers.entries()) {
+      memberPlayersObj[uid] = players
+    }
+
+    io.to(`room:${testRoomId}`).emit('member-joined', {
+      roomId: testRoomId,
+      userId: testGuestId2,
+      members,
+      memberPlayers: memberPlayersObj,
+    })
+
+    // Wait for the socket broadcast with timeout
+    const data = await memberJoinedPromise
+
+    // Verify the broadcast data
+    expect(data).toBeDefined()
+    expect(data.roomId).toBe(testRoomId)
+    expect(data.userId).toBe(testGuestId2)
+    expect(data.members).toBeDefined()
+    expect(Array.isArray(data.members)).toBe(true)
+
+    // Verify both users are in the members list
+    const memberUserIds = data.members.map((m: any) => m.userId)
+    expect(memberUserIds).toContain(testGuestId1)
+    expect(memberUserIds).toContain(testGuestId2)
+
+    // Verify the new member details
+    const addedMember = data.members.find((m: any) => m.userId === testGuestId2)
+    expect(addedMember).toBeDefined()
+    expect(addedMember.displayName).toBe('User 2')
+    expect(addedMember.roomId).toBe(testRoomId)
+  })
+
+  it('should broadcast member-left when a user leaves via API', async () => {
+    // User 1 joins the room first
+    await addRoomMember({
+      roomId: testRoomId,
+      userId: testGuestId1,
+      displayName: 'User 1',
+      isCreator: false,
+    })
+
+    // User 2 joins the room
+    await addRoomMember({
+      roomId: testRoomId,
+      userId: testGuestId2,
+      displayName: 'User 2',
+      isCreator: false,
+    })
+
+    // User 1 connects to socket
+    socket1 = ioClient(`http://localhost:${serverPort}`, {
+      path: '/api/socket',
+      transports: ['websocket'],
+    })
+
+    await new Promise<void>((resolve) => {
+      socket1.on('connect', () => resolve())
+    })
+
+    socket1.emit('join-room', { roomId: testRoomId, userId: testGuestId1 })
+
+    await new Promise<void>((resolve) => {
+      socket1.on('room-joined', () => resolve())
+    })
+
+    // Set up listener for member-left event
+    const memberLeftPromise = new Promise<any>((resolve) => {
+      socket1.on('member-left', (data) => {
+        resolve(data)
+      })
+    })
+
+    // User 2 leaves the room via API
+    await db.delete(schema.roomMembers).where(eq(schema.roomMembers.userId, testGuestId2))
+
+    // Manually trigger the leave broadcast (simulating what the API does)
+    const { getSocketIO } = await import('../src/lib/socket-io')
+    const io = await getSocketIO()
+    if (io) {
+      const { getRoomMembers } = await import('../src/lib/arcade/room-membership')
+      const { getRoomActivePlayers } = await import('../src/lib/arcade/player-manager')
+
+      const members = await getRoomMembers(testRoomId)
+      const memberPlayers = await getRoomActivePlayers(testRoomId)
+
+      const memberPlayersObj: Record<string, any[]> = {}
+      for (const [uid, players] of memberPlayers.entries()) {
+        memberPlayersObj[uid] = players
+      }
+
+      io.to(`room:${testRoomId}`).emit('member-left', {
+        roomId: testRoomId,
+        userId: testGuestId2,
+        members,
+        memberPlayers: memberPlayersObj,
+      })
+    }
+
+    // Wait for the socket broadcast with timeout
+    const data = await Promise.race([
+      memberLeftPromise,
+      new Promise((_, reject) =>
+        setTimeout(() => reject(new Error('Timeout waiting for member-left event')), 2000)
+      ),
+    ])
+
+    // Verify the broadcast data
+    expect(data).toBeDefined()
+    expect(data.roomId).toBe(testRoomId)
+    expect(data.userId).toBe(testGuestId2)
+    expect(data.members).toBeDefined()
+    expect(Array.isArray(data.members)).toBe(true)
+
+    // Verify User 2 is no longer in the members list
+    const memberUserIds = data.members.map((m: any) => m.userId)
+    expect(memberUserIds).toContain(testGuestId1)
+    expect(memberUserIds).not.toContain(testGuestId2)
+  })
+
+  it('should update both members and players lists in member-joined broadcast', async () => {
+    // Create an active player for User 2
+    const [player2] = await db
+      .insert(schema.players)
+      .values({
+        userId: testUserId2,
+        name: 'Player 2',
+        emoji: '🎮',
+        color: '#3b82f6',
+        isActive: true,
+      })
+      .returning()
+
+    // User 1 connects and joins room
+    socket1 = ioClient(`http://localhost:${serverPort}`, {
+      path: '/api/socket',
+      transports: ['websocket'],
+    })
+
+    await new Promise<void>((resolve) => {
+      socket1.on('connect', () => resolve())
+    })
+
+    socket1.emit('join-room', { roomId: testRoomId, userId: testGuestId1 })
+
+    await new Promise<void>((resolve) => {
+      socket1.on('room-joined', () => resolve())
+    })
+
+    const memberJoinedPromise = new Promise<any>((resolve) => {
+      socket1.on('member-joined', (data) => {
+        resolve(data)
+      })
+    })
+
+    // User 2 joins via API
+    await addRoomMember({
+      roomId: testRoomId,
+      userId: testGuestId2,
+      displayName: 'User 2',
+      isCreator: false,
+    })
+
+    // Manually trigger the broadcast (simulating what the API does)
+    const { getRoomMembers: getRoomMembers3 } = await import('../src/lib/arcade/room-membership')
+    const { getRoomActivePlayers: getRoomActivePlayers3 } = await import(
+      '../src/lib/arcade/player-manager'
+    )
+
+    const members2 = await getRoomMembers3(testRoomId)
+    const memberPlayers2 = await getRoomActivePlayers3(testRoomId)
+
+    const memberPlayersObj2: Record<string, any[]> = {}
+    for (const [uid, players] of memberPlayers2.entries()) {
+      memberPlayersObj2[uid] = players
+    }
+
+    io.to(`room:${testRoomId}`).emit('member-joined', {
+      roomId: testRoomId,
+      userId: testGuestId2,
+      members: members2,
+      memberPlayers: memberPlayersObj2,
+    })
+
+    const data = await Promise.race([
+      memberJoinedPromise,
+      new Promise((_, reject) => setTimeout(() => reject(new Error('Timeout')), 2000)),
+    ])
+
+    // Verify members list is updated
+    expect(data.members).toBeDefined()
+    const memberUserIds = data.members.map((m: any) => m.userId)
+    expect(memberUserIds).toContain(testGuestId2)
+
+    // Verify players list is updated
+    expect(data.memberPlayers).toBeDefined()
+    expect(data.memberPlayers[testGuestId2]).toBeDefined()
+    expect(Array.isArray(data.memberPlayers[testGuestId2])).toBe(true)
+
+    // User 2's players should include the active player we created
+    const user2Players = data.memberPlayers[testGuestId2]
+    expect(user2Players.length).toBeGreaterThan(0)
+    expect(user2Players.some((p: any) => p.id === player2.id)).toBe(true)
+
+    // Clean up player
+    await db.delete(schema.players).where(eq(schema.players.id, player2.id))
+  })
+})

apps/web/docs/FIXES-APPLIED.md

@@ -0,0 +1,169 @@
+# User/Player/Room Member Inconsistencies - FIXED ✅
+
+All critical inconsistencies between users, players, and room members have been resolved.
+
+## Summary of Fixes
+
+### 1. ✅ Backend - Player Fetching
+
+**Created**: `src/lib/arcade/player-manager.ts`
+- `getActivePlayers(userId)` - Get a user's active players
+- `getRoomActivePlayers(roomId)` - Get all active players for all members in a room
+- `getRoomPlayerIds(roomId)` - Get flat list of all player IDs in a room
+- `validatePlayerInRoom(playerId, roomId)` - Validate player belongs to room member
+- `getPlayer(playerId)` - Get single player by ID
+- `getPlayers(playerIds[])` - Get multiple players by IDs
+
+### 2. ✅ API Endpoints Updated
+
+**`/api/arcade/rooms/:roomId/join` (POST)**
+```typescript
+// Now returns:
+{
+  member: RoomMember,
+  room: Room,
+  activePlayers: Player[], // USER's active players
+  alreadyMember: boolean
+}
+```
+
+**`/api/arcade/rooms/:roomId` (GET)**
+```typescript
+// Now returns:
+{
+  room: Room,
+  members: RoomMember[],
+  memberPlayers: Record<userId, Player[]>, // Map of all members' players
+  canModerate: boolean
+}
+```
+
+**`/api/arcade/rooms` (GET)**
+```typescript
+// Now returns:
+{
+  rooms: Array<{
+    ...roomData,
+    memberCount: number,  // Number of users in room
+    playerCount: number   // Total players across all users
+  }>
+}
+```
+
+### 3. ✅ Socket Events Updated
+
+**`join-room` event**
+```typescript
+// Server emits:
+socket.emit('room-joined', {
+  room,
+  members,
+  onlineMembers,
+  memberPlayers: Record<userId, Player[]>,  // All members' players
+  activePlayers: Player[]  // This user's active players
+})
+
+socket.to(`room:${roomId}`).emit('member-joined', {
+  member,
+  activePlayers: Player[],  // New member's active players
+  onlineMembers,
+  memberPlayers: Record<userId, Player[]>
+})
+```
+
+**`room-game-move` event**
+```typescript
+// Now validates:
+1. User is a room member (userId check)
+2. Player belongs to a room member (playerId validation)
+
+// Rejects move if playerId doesn't belong to any room member
+```
+
+### 4. ✅ Frontend UI Updated
+
+**Room Lobby (`/arcade/rooms/[roomId]/page.tsx`)**
+
+Before:
+```
+Member: Jane
+  Status: Online
+```
+
+After:
+```
+Member: Jane
+  Status: Online
+  Players: 👧 Alice, 👦 Bob
+```
+
+**Room Browser (`/arcade/rooms/page.tsx`)**
+
+Before:
+```
+Room: Math Masters
+  Host: Jane | Game: matching | Status: Waiting
+```
+
+After:
+```
+Room: Math Masters
+  Host: Jane | Game: matching | 👥 3 members | 🎯 7 players | Status: Waiting
+```
+
+## Key Changes Summary
+
+| Component | Change |
+|-----------|--------|
+| **Helper Functions** | Created `player-manager.ts` with 6 new functions |
+| **Join Endpoint** | Now fetches and returns user's active players |
+| **Room Detail Endpoint** | Returns player map for all members |
+| **Rooms List Endpoint** | Returns member and player counts |
+| **Socket join-room** | Broadcasts active players to room |
+| **Socket room-game-move** | Validates player IDs belong to members |
+| **Room Lobby UI** | Shows each member's players |
+| **Room Browser UI** | Shows total member and player counts |
+
+## Validation Rules Enforced
+
+1. ✅ **Room membership tracked by USER ID** - Correct
+2. ✅ **Game participation tracked by PLAYER IDs** - Fixed
+3. ✅ **When user joins room, their active players join game** - Implemented
+4. ✅ **Socket moves validate player belongs to room** - Added validation
+5. ✅ **UI shows both members and their players** - Updated
+
+## TypeScript Validation
+
+All changes pass TypeScript validation with 0 errors in modified files:
+- `src/lib/arcade/player-manager.ts` ✅
+- `src/app/api/arcade/rooms/route.ts` ✅
+- `src/app/api/arcade/rooms/[roomId]/route.ts` ✅
+- `src/app/api/arcade/rooms/[roomId]/join/route.ts` ✅
+- `src/app/arcade/rooms/page.tsx` ✅
+- `src/app/arcade/rooms/[roomId]/page.tsx` ✅
+- `socket-server.ts` ✅
+
+## Testing Checklist
+
+- [ ] Create a user with multiple active players
+- [ ] Join a room and verify all active players are shown
+- [ ] Have multiple users join the same room
+- [ ] Verify each user's players are displayed correctly
+- [ ] Verify room browser shows correct member/player counts
+- [ ] Start a game and verify all player IDs are collected
+- [ ] Test that invalid player IDs are rejected in game moves
+
+## Documentation Created
+
+1. `docs/terminology-user-player-room.md` - Complete explanation
+2. `.claude/terminology.md` - Quick reference for AI
+3. `docs/INCONSISTENCIES.md` - Analysis of issues (pre-fix)
+4. `docs/FIXES-APPLIED.md` - This document
+
+## Next Steps (Phase 4)
+
+The system is now ready for full multiplayer game integration:
+1. When room game starts, collect all player IDs from all members
+2. Set `arcade_sessions.activePlayers` to all room player IDs
+3. Game state tracks scores/moves by PLAYER ID
+4. Broadcast game updates to all room members

apps/web/docs/INCONSISTENCIES.md

@@ -0,0 +1,189 @@
+# Current Implementation vs Correct Design - Inconsistencies
+
+## ❌ Inconsistency 1: Room Join Doesn't Fetch Active Players
+
+**Current Code** (`/api/arcade/rooms/:roomId/join`):
+```typescript
+// Only creates room_member record with userId
+const member = await addRoomMember({
+  roomId,
+  userId: viewerId,  // ✅ Correct: USER ID
+  displayName,
+  isCreator: false,
+})
+// ❌ Missing: Does not fetch user's active players
+```
+
+**Should Be**:
+```typescript
+// 1. Create room member
+const member = await addRoomMember({ ... })
+
+// 2. Fetch user's active players
+const activePlayers = await db.query.players.findMany({
+  where: and(
+    eq(players.userId, viewerId),
+    eq(players.isActive, true)
+  )
+})
+
+// 3. Return both member and their active players
+return { member, activePlayers }
+```
+
+---
+
+## ❌ Inconsistency 2: Socket Events Use USER ID Instead of PLAYER ID
+
+**Current Code** (`socket-server.ts`):
+```typescript
+socket.on('join-room', ({ roomId, userId }) => {
+  // Uses USER ID for presence
+  await setMemberOnline(roomId, userId, true)
+  socket.emit('room-joined', { members })
+})
+
+socket.on('room-game-move', ({ roomId, userId, move }) => {
+  // ❌ Wrong: Uses USER ID for game moves
+  // Should use PLAYER ID
+})
+```
+
+**Should Be**:
+```typescript
+socket.on('join-room', ({ roomId, userId }) => {
+  // ✅ Correct: Use USER ID for room presence
+  await setMemberOnline(roomId, userId, true)
+
+  // ❌ Missing: Should also fetch and broadcast active players
+  const activePlayers = await getActivePlayers(userId)
+  socket.emit('room-joined', { members, activePlayers })
+})
+
+socket.on('room-game-move', ({ roomId, playerId, move }) => {
+  // ✅ Correct: Use PLAYER ID for game actions
+  // Validate that playerId belongs to a member in this room
+})
+```
+
+---
+
+## ❌ Inconsistency 3: Room Member Interface Missing Player Association
+
+**Current Code** (`room_members` table):
+```typescript
+interface RoomMember {
+  id: string
+  roomId: string
+  userId: string       // ✅ Correct: USER ID
+  displayName: string
+  isCreator: boolean
+  // ❌ Missing: No link to user's players
+}
+```
+
+**Need to Add** (runtime association, not DB schema):
+```typescript
+interface RoomMemberWithPlayers {
+  member: RoomMember
+  activePlayers: Player[]  // The user's active players
+}
+```
+
+---
+
+## ❌ Inconsistency 4: Client UI Shows Room Members, Not Players
+
+**Current Code** (`/arcade/rooms/[roomId]/page.tsx`):
+```typescript
+// Shows room members (users)
+{members.map((member) => (
+  <div key={member.id}>
+    {member.displayName} {/* USER's display name */}
+  </div>
+))}
+
+// ❌ Missing: Should show the PLAYERS that will participate
+```
+
+**Should Show**:
+```typescript
+{members.map((member) => (
+  <div key={member.id}>
+    <div>{member.displayName} (Room Member)</div>
+    <div>Players:
+      {member.activePlayers.map(player => (
+        <span key={player.id}>{player.emoji} {player.name}</span>
+      ))}
+    </div>
+  </div>
+))}
+```
+
+---
+
+## Summary of Required Changes
+
+### Phase 1: Backend - Player Fetching
+1. ✅ `room_members` table correctly uses USER ID (no change needed)
+2. ❌ `/api/arcade/rooms/:roomId/join` - Fetch and return active players
+3. ❌ `/api/arcade/rooms/:roomId` GET - Include active players in response
+4. ❌ Create helper: `getActivePlayers(userId) => Player[]`
+
+### Phase 2: Socket Layer - Player Association
+1. ❌ `join-room` event - Broadcast active players to room
+2. ❌ `room-game-move` event - Accept PLAYER ID, not USER ID
+3. ❌ Validate PLAYER ID belongs to a room member
+
+### Phase 3: Frontend - Player Display
+1. ❌ Room lobby - Show each member's active players
+2. ❌ Game setup - Use PLAYER IDs for `activePlayers` array
+3. ❌ Move/action events - Send PLAYER ID
+
+### Phase 4: Game Integration
+1. ❌ When room game starts, collect all PLAYER IDs from all members
+2. ❌ Arcade session `activePlayers` should contain all room PLAYER IDs
+3. ❌ Game state tracks scores/moves by PLAYER ID, not USER ID
+
+---
+
+## Test Scenarios
+
+### Scenario 1: Single Player Per User
+```
+USER Jane (guest_123)
+  └─ PLAYER Alice (active)
+
+Joins room → Room shows "Jane: Alice 👧"
+Game starts → activePlayers: ["alice_id"]
+```
+
+### Scenario 2: Multiple Players Per User
+```
+USER Jane (guest_123)
+  ├─ PLAYER Alice (active)
+  └─ PLAYER Bob (active)
+
+Joins room → Room shows "Jane: Alice 👧, Bob 👦"
+Game starts → activePlayers: ["alice_id", "bob_id"]
+```
+
+### Scenario 3: Multi-User Room
+```
+USER Jane
+  └─ PLAYER Alice, Bob (active)
+
+USER Mark
+  └─ PLAYER Mario (active)
+
+USER Sara
+  └─ PLAYER Luna, Nova, Star (active)
+
+Room shows:
+  - Jane: Alice 👧, Bob 👦
+  - Mark: Mario 🍄
+  - Sara: Luna 🌙, Nova ✨, Star ⭐
+
+Game starts → activePlayers: [alice, bob, mario, luna, nova, star]
+Total: 6 players across 3 users
+```

apps/web/docs/MULTIPLAYER_SYNC_ARCHITECTURE.md

@@ -0,0 +1,490 @@
+# Multiplayer Synchronization Architecture
+
+## Current State: Single-User Multi-Tab Sync
+
+### How it Works
+
+**Client-Side Flow:**
+
+1. User opens game in Tab A and Tab B
+2. Both tabs create WebSocket connections via `useArcadeSocket()`
+3. Both emit `join-arcade-session` with `userId`
+4. Server adds both sockets to `arcade:${userId}` room
+
+**When User Makes a Move (from Tab A):**
+
+```typescript
+// Client (Tab A)
+sendMove({ type: 'FLIP_CARD', playerId: 'player-1', data: { cardId: 'card-5' } })
+
+// Optimistic update applied locally
+state = applyMoveOptimistically(state, move)
+
+// Socket emits to server
+socket.emit('game-move', { userId, move })
+```
+
+**Server Processing:**
+
+```typescript
+// socket-server.ts line 71
+socket.on('game-move', async (data) => {
+  // Validate move
+  const result = await applyGameMove(data.userId, data.move)
+
+  if (result.success) {
+    // ✅ Broadcast to ALL tabs of this user
+    io.to(`arcade:${data.userId}`).emit('move-accepted', {
+      gameState: result.session.gameState,
+      version: result.session.version,
+      move: data.move
+    })
+  }
+})
+```
+
+**Both Tabs Receive Update:**
+
+```typescript
+// Client (Tab A and Tab B)
+socket.on('move-accepted', (data) => {
+  // Update server state
+  optimistic.handleMoveAccepted(data.gameState, data.version, data.move)
+
+  // Tab A: Remove from pending queue (was optimistic)
+  // Tab B: Just sync with server state (wasn't expecting it)
+})
+```
+
+### Key Components
+
+1. **`useOptimisticGameState`** - Manages optimistic updates
+   - Keeps `serverState` (last confirmed by server)
+   - Keeps `pendingMoves[]` (not yet confirmed)
+   - Current state = serverState + all pending moves applied
+
+2. **`useArcadeSession`** - Combines socket + optimistic state
+   - Connects socket
+   - Applies moves optimistically
+   - Sends moves to server
+   - Handles server responses
+
+3. **Socket Rooms** - Server-side broadcast channels
+   - `arcade:${userId}` - All tabs of one user
+   - Each socket can be in multiple rooms
+   - `io.to(room).emit()` broadcasts to all sockets in that room
+
+4. **Session Storage** - Database
+   - One session per user (userId is unique key)
+   - Contains `gameState`, `version`, `roomId`
+   - Optimistic locking via version number
+
+---
+
+## Required: Room-Based Multi-User Sync
+
+### The Goal
+
+Multiple users in the same room at `/arcade/room` should all see synchronized game state:
+
+- User A (2 tabs): Tab A1, Tab A2
+- User B (1 tab): Tab B1
+- User C (2 tabs): Tab C1, Tab C2
+
+When User A makes a move in Tab A1:
+- **All of User A's tabs** see the move (Tab A1, Tab A2)
+- **All of User B's tabs** see the move (Tab B1)
+- **All of User C's tabs** see the move (Tab C1, Tab C2)
+
+### The Challenge
+
+Current architecture only broadcasts within one user:
+```typescript
+// ❌ Only reaches User A's tabs
+io.to(`arcade:${userA}`).emit('move-accepted', ...)
+```
+
+We need to broadcast to the entire room:
+```typescript
+// ✅ Reaches all users in the room
+io.to(`game:${roomId}`).emit('move-accepted', ...)
+```
+
+### The Solution
+
+#### 1. Add Room-Based Game Socket Room
+
+When a user joins `/arcade/room`, they join TWO socket rooms:
+
+```typescript
+// socket-server.ts - extend join-arcade-session
+socket.on('join-arcade-session', async ({ userId, roomId }) => {
+  // Join user's personal room (for multi-tab sync)
+  socket.join(`arcade:${userId}`)
+
+  // If this session is part of a room, also join the game room
+  if (roomId) {
+    socket.join(`game:${roomId}`)
+    console.log(`🎮 User ${userId} joined game room ${roomId}`)
+  }
+
+  // Send current session state...
+})
+```
+
+#### 2. Broadcast to Both Rooms
+
+When processing moves for room-based sessions:
+
+```typescript
+// socket-server.ts - modify game-move handler
+socket.on('game-move', async (data) => {
+  const result = await applyGameMove(data.userId, data.move)
+
+  if (result.success && result.session) {
+    const moveAcceptedData = {
+      gameState: result.session.gameState,
+      version: result.session.version,
+      move: data.move,
+    }
+
+    // Broadcast to user's own tabs (for optimistic update reconciliation)
+    io.to(`arcade:${data.userId}`).emit('move-accepted', moveAcceptedData)
+
+    // If this is a room-based session, ALSO broadcast to all room members
+    if (result.session.roomId) {
+      io.to(`game:${result.session.roomId}`).emit('move-accepted', moveAcceptedData)
+      console.log(`📢 Broadcasted move to room ${result.session.roomId}`)
+    }
+  }
+})
+```
+
+**Why broadcast to both?**
+- `arcade:${userId}` - So the acting user's tabs can reconcile their optimistic updates
+- `game:${roomId}` - So all other users in the room receive the update
+
+#### 3. Client Handles Own vs. Other Moves
+
+The client already handles this correctly via optimistic updates:
+
+```typescript
+// User A (Tab A1) - Makes move
+sendMove({ type: 'FLIP_CARD', ... })
+// → Applies optimistically immediately
+// → Sends to server
+// → Receives move-accepted
+// → Reconciles: removes from pending queue
+
+// User B (Tab B1) - Sees move from User A
+// → Receives move-accepted (unexpected)
+// → Reconciles: clears pending queue, syncs with server state
+// → Result: sees User A's move immediately
+```
+
+The beauty is that `handleMoveAccepted()` already handles both cases:
+- **Own move**: Remove from pending queue
+- **Other's move**: Clear pending queue (since server state is now ahead)
+
+#### 4. Pass roomId in join-arcade-session
+
+Client needs to send roomId when joining:
+
+```typescript
+// hooks/useArcadeSocket.ts
+const joinSession = useCallback((userId: string, roomId?: string) => {
+  if (!socket) return
+  socket.emit('join-arcade-session', { userId, roomId })
+}, [socket])
+
+// hooks/useArcadeSession.ts
+useEffect(() => {
+  if (connected && autoJoin && userId) {
+    // Get roomId from session or room context
+    const roomId = getRoomId() // Need to provide this
+    joinSession(userId, roomId)
+  }
+}, [connected, autoJoin, userId, joinSession])
+```
+
+---
+
+## Implementation Plan
+
+### Phase 1: Server-Side Changes
+
+**File: `socket-server.ts`**
+
+1. ✅ Accept `roomId` in `join-arcade-session` event
+   ```typescript
+   socket.on('join-arcade-session', async ({ userId, roomId }) => {
+     socket.join(`arcade:${userId}`)
+
+     // Join game room if session is room-based
+     if (roomId) {
+       socket.join(`game:${roomId}`)
+     }
+
+     // Rest of logic...
+   })
+   ```
+
+2. ✅ Broadcast to room in `game-move` handler
+   ```typescript
+   if (result.success && result.session) {
+     const moveData = {
+       gameState: result.session.gameState,
+       version: result.session.version,
+       move: data.move,
+     }
+
+     // Broadcast to user's tabs
+     io.to(`arcade:${data.userId}`).emit('move-accepted', moveData)
+
+     // ALSO broadcast to room if room-based session
+     if (result.session.roomId) {
+       io.to(`game:${result.session.roomId}`).emit('move-accepted', moveData)
+     }
+   }
+   ```
+
+3. ✅ Handle room disconnects
+   ```typescript
+   socket.on('disconnect', () => {
+     // Leave all rooms (handled automatically by socket.io)
+     // But log for debugging
+     if (currentUserId && currentRoomId) {
+       console.log(`User ${currentUserId} left game room ${currentRoomId}`)
+     }
+   })
+   ```
+
+### Phase 2: Client-Side Changes
+
+**File: `hooks/useArcadeSocket.ts`**
+
+1. ✅ Add roomId parameter to joinSession
+   ```typescript
+   export interface UseArcadeSocketReturn {
+     // ... existing
+     joinSession: (userId: string, roomId?: string) => void
+   }
+
+   const joinSession = useCallback((userId: string, roomId?: string) => {
+     if (!socket) return
+     socket.emit('join-arcade-session', { userId, roomId })
+   }, [socket])
+   ```
+
+**File: `hooks/useArcadeSession.ts`**
+
+2. ✅ Accept roomId in options
+   ```typescript
+   export interface UseArcadeSessionOptions<TState> {
+     userId: string
+     roomId?: string // NEW
+     initialState: TState
+     applyMove: (state: TState, move: GameMove) => TState
+     // ... rest
+   }
+
+   export function useArcadeSession<TState>(options: UseArcadeSessionOptions<TState>) {
+     const { userId, roomId, ...optimisticOptions } = options
+
+     // Auto-join with roomId
+     useEffect(() => {
+       if (connected && autoJoin && userId) {
+         joinSession(userId, roomId)
+       }
+     }, [connected, autoJoin, userId, roomId, joinSession])
+
+     // ... rest
+   }
+   ```
+
+**File: `app/arcade/matching/context/ArcadeMemoryPairsContext.tsx`**
+
+3. ✅ Get roomId from room data and pass to session
+   ```typescript
+   import { useRoomData } from '@/hooks/useRoomData'
+
+   export function ArcadeMemoryPairsProvider({ children }: { children: ReactNode }) {
+     const { data: viewerId } = useViewerId()
+     const { roomData } = useRoomData()
+
+     // Arcade session integration
+     const { state, sendMove, ... } = useArcadeSession<MemoryPairsState>({
+       userId: viewerId || '',
+       roomId: roomData?.id, // NEW - pass room ID
+       initialState,
+       applyMove: applyMoveOptimistically,
+     })
+
+     // ... rest stays the same
+   }
+   ```
+
+### Phase 3: Testing
+
+1. **Multi-Tab Test (Single User)**
+   - Open `/arcade/room` in 2 tabs as User A
+   - Make move in Tab 1
+   - Verify Tab 2 updates immediately
+
+2. **Multi-User Test (Different Users)**
+   - User A opens `/arcade/room` in 1 tab
+   - User B opens `/arcade/room` in 1 tab (same room)
+   - User A makes move
+   - Verify User B sees move immediately
+
+3. **Multi-User Multi-Tab Test**
+   - User A: 2 tabs (Tab A1, Tab A2)
+   - User B: 2 tabs (Tab B1, Tab B2)
+   - User A makes move in Tab A1
+   - Verify all 4 tabs update
+
+4. **Rapid Move Test**
+   - User A and User B both make moves rapidly
+   - Verify no conflicts
+   - Verify all moves are processed in order
+
+---
+
+## Edge Cases to Handle
+
+### 1. User Leaves Room Mid-Game
+
+**Current behavior:** Session persists, user can rejoin
+
+**Required behavior:**
+- If user leaves room (HTTP POST to `/api/arcade/rooms/[roomId]/leave`):
+  - Delete their session
+  - Emit `session-ended` to their tabs
+  - Other users continue playing
+
+### 2. Version Conflicts
+
+**Already handled** by optimistic locking:
+- Each move increments version
+- Client tracks server version
+- If conflict detected, reconciliation happens automatically
+
+### 3. Session Without Room
+
+**Already handled** by session-manager.ts:
+- Sessions without `roomId` are considered orphaned
+- They're cleaned up on next access (lines 111-115)
+
+### 4. Multiple Users Same Move
+
+**Handled by server validation:**
+- Server processes moves sequentially
+- First valid move wins
+- Second move gets rejected if it's now invalid
+- Client rolls back rejected move
+
+---
+
+## Benefits of This Architecture
+
+1. **Reuses existing optimistic update system**
+   - No changes needed to client-side optimistic logic
+   - Already handles own vs. others' moves
+
+2. **Minimal changes required**
+   - Add `roomId` parameter (3 places)
+   - Add one `io.to()` broadcast (1 place)
+   - Wire up roomId from context (1 place)
+
+3. **Backward compatible**
+   - Non-room sessions still work (roomId is optional)
+   - Solo play unaffected
+
+4. **Scalable**
+   - Socket.io handles multiple rooms efficiently
+   - No N² broadcasting (room-based is O(N))
+
+5. **Already tested pattern**
+   - Multi-tab sync proves the broadcast pattern works
+   - Just extending to more sockets (different users)
+
+---
+
+## Security Considerations
+
+### 1. Validate Room Membership
+
+Before processing moves, verify user is in the room:
+
+```typescript
+// session-manager.ts - in applyGameMove()
+const session = await getArcadeSession(userId)
+
+if (session.roomId) {
+  // Verify user is a member of this room
+  const membership = await getRoomMember(session.roomId, userId)
+  if (!membership) {
+    return { success: false, error: 'User not in room' }
+  }
+}
+```
+
+### 2. Verify Player Ownership
+
+Ensure users can only make moves for their own players:
+
+```typescript
+// Already handled in validator
+// move.playerId must be in session.activePlayers
+// activePlayers are owned by the userId making the move
+```
+
+This is already enforced by how activePlayers are set up in the room.
+
+---
+
+## Performance Considerations
+
+### 1. Broadcasting Overhead
+
+- **Current**: 1 user × N tabs = N broadcasts per move
+- **New**: M users × N tabs each = (M×N) broadcasts per move
+- **Impact**: Linear with room size, not quadratic
+- **Acceptable**: Socket.io is optimized for this
+
+### 2. Database Queries
+
+- No change: Still 1 database write per move
+- Session is stored per-user, not per-room
+- Room data is separate (cached, not updated per move)
+
+### 3. Memory
+
+- Each socket joins 2 rooms instead of 1
+- Negligible: Socket.io uses efficient room data structures
+
+---
+
+## Testing Checklist
+
+### Unit Tests
+
+- [ ] `useArcadeSocket` accepts and passes roomId
+- [ ] `useArcadeSession` accepts and passes roomId
+- [ ] Server joins `game:${roomId}` room when roomId provided
+
+### Integration Tests
+
+- [ ] Single user, 2 tabs: both tabs sync
+- [ ] 2 users, 1 tab each: both users sync
+- [ ] 2 users, 2 tabs each: all 4 tabs sync
+- [ ] User leaves room: session deleted, others continue
+- [ ] Rapid concurrent moves: all processed correctly
+
+### Manual Tests
+
+- [ ] Open room in 2 browsers (different users)
+- [ ] Play full game to completion
+- [ ] Verify scores sync correctly
+- [ ] Verify turn changes sync correctly
+- [ ] Verify game completion syncs correctly

apps/web/docs/terminology-user-player-room.md

@@ -0,0 +1,153 @@
+# User vs Player vs Room Member - Terminology Guide
+
+**Critical Distinction**: Users, Players, and Room Members are three different concepts in the system.
+
+## Core Concepts
+
+### 1. **USER** (Identity Layer)
+- **Table**: `users`
+- **Purpose**: Identity - guest or authenticated account
+- **Identified by**: `guestId` (HttpOnly cookie)
+- **Retrieved via**: `useViewerId()` hook
+- **Scope**: One per browser/account
+- **Example**: A person visiting the site
+
+### 2. **PLAYER** (Game Avatar Layer)
+- **Table**: `players`
+- **Purpose**: Game profiles/avatars that represent a participant in the game
+- **Belongs to**: USER (via `userId` FK)
+- **Properties**: name, emoji, color, `isActive`
+- **Scope**: A USER can have MULTIPLE players (e.g., "Alice 👧", "Bob 👦", "Charlie 🧒")
+- **Used in**: All game contexts - both local and online multiplayer
+- **Active Players**: Players where `isActive = true` are the ones currently participating
+
+### 3. **ROOM MEMBER** (Room Participation Layer)
+- **Table**: `room_members`
+- **Purpose**: Tracks a USER's participation in a multiplayer room
+- **Identified by**: `userId` (references the guest/user)
+- **Properties**: `displayName`, `isCreator`, `isOnline`, `joinedAt`
+- **Scope**: One record per USER per room
+
+## How They Work Together
+
+### When a USER joins a room:
+
+1. **Room Member Created**: A `room_members` record is created with the USER's ID
+2. **Active Players Join**: The USER's ACTIVE PLAYERS (where `isActive = true`) participate in the game
+3. **Arcade Session**: The `arcade_sessions.activePlayers` field contains the PLAYER IDs (from `players` table)
+
+### Example Flow:
+
+```
+USER: guest_abc123 (Jane)
+  ├─ PLAYER: player_001 (name: "Alice 👧", isActive: true)
+  ├─ PLAYER: player_002 (name: "Bob 👦", isActive: true)
+  └─ PLAYER: player_003 (name: "Charlie 🧒", isActive: false)
+
+When USER joins ROOM "Math Masters":
+  → ROOM_MEMBER created: {userId: "guest_abc123", displayName: "Jane", roomId: "room_xyz"}
+  → PLAYERS joining game: ["player_001", "player_002"] (only active ones)
+  → ARCADE_SESSION.activePlayers: ["player_001", "player_002"]
+```
+
+### Multi-User Room Example:
+
+```
+ROOM "Math Masters" (room_xyz):
+
+  ROOM_MEMBER 1:
+    userId: guest_abc123 (Jane)
+    └─ PLAYERS in game: ["player_001" (Alice), "player_002" (Bob)]
+
+  ROOM_MEMBER 2:
+    userId: guest_def456 (Mark)
+    └─ PLAYERS in game: ["player_003" (Mario)]
+
+  ROOM_MEMBER 3:
+    userId: guest_ghi789 (Sara)
+    └─ PLAYERS in game: ["player_004" (Luna), "player_005" (Nova), "player_006" (Star)]
+
+Total PLAYERS in this game: 6 players across 3 users
+```
+
+## Database Schema Relationships
+
+```
+users (1) ──< (many) players
+  │
+  └──< (many) room_members
+                 │
+                 └──< belongs to arcade_rooms
+
+arcade_sessions:
+  - userId: references users.id
+  - activePlayers: JSON array of player.id values
+  - roomId: references arcade_rooms.id (null for solo play)
+```
+
+## Implementation Rules
+
+### ✅ Correct Usage
+
+- **Room membership**: Track by USER ID
+- **Game participation**: Track by PLAYER IDs
+- **Presence/online status**: Track by USER ID (room member)
+- **Scores/moves**: Track by PLAYER ID
+- **Room creator**: Track by USER ID
+
+### ❌ Common Mistakes
+
+- ❌ Using USER ID where PLAYER ID is needed
+- ❌ Assuming one USER = one PLAYER
+- ❌ Tracking scores by USER instead of PLAYER
+- ❌ Mixing room_members.displayName with players.name
+
+## API Design Patterns
+
+### When a USER joins a room:
+
+```typescript
+// 1. Add user as room member
+POST /api/arcade/rooms/:roomId/join
+Body: {
+  userId: string        // USER ID (from useViewerId)
+  displayName: string   // Room member display name
+}
+
+// 2. System retrieves user's active players
+const activePlayers = await db.query.players.findMany({
+  where: and(
+    eq(players.userId, userId),
+    eq(players.isActive, true)
+  )
+})
+
+// 3. Game starts with those player IDs
+const session = {
+  userId,
+  activePlayers: activePlayers.map(p => p.id), // PLAYER IDs
+  roomId
+}
+```
+
+### Socket Events
+
+```typescript
+// User joins room (presence)
+socket.emit('join-room', { roomId, userId })
+
+// Player makes a move (game action)
+socket.emit('game-move', {
+  roomId,
+  playerId, // PLAYER ID, not USER ID
+  move
+})
+```
+
+## Summary
+
+- **USER** = Identity/account (one per person)
+- **PLAYER** = Game avatar/profile (multiple per user)
+- **ROOM MEMBER** = USER's participation in a room
+- **When USER joins room** → Their ACTIVE PLAYERS join the game
+- **`activePlayers` field** → Array of PLAYER IDs from `players` table

apps/web/drizzle/0004_shiny_madelyne_pryor.sql

@@ -0,0 +1,15 @@
+-- Step 1: Clean up any duplicate room memberships
+-- Keep only the most recent membership for each user (by last_seen timestamp)
+DELETE FROM `room_members`
+WHERE `id` NOT IN (
+  SELECT `id` FROM (
+    SELECT `id`, ROW_NUMBER() OVER (
+      PARTITION BY `user_id`
+      ORDER BY `last_seen` DESC, `joined_at` DESC
+    ) as rn
+    FROM `room_members`
+  ) WHERE rn = 1
+);--> statement-breakpoint
+
+-- Step 2: Add unique constraint to enforce one room per user
+CREATE UNIQUE INDEX `idx_room_members_user_id_unique` ON `room_members` (`user_id`);

apps/web/drizzle/meta/0004_snapshot.json

@@ -0,0 +1,660 @@
+{
+  "version": "6",
+  "dialect": "sqlite",
+  "id": "cbd94d51-1454-467c-a471-ccbfca886a1a",
+  "prevId": "68cc273f-0d84-4a46-ae41-124a3e06096b",
+  "tables": {
+    "abacus_settings": {
+      "name": "abacus_settings",
+      "columns": {
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "color_scheme": {
+          "name": "color_scheme",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'place-value'"
+        },
+        "bead_shape": {
+          "name": "bead_shape",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'diamond'"
+        },
+        "color_palette": {
+          "name": "color_palette",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'default'"
+        },
+        "hide_inactive_beads": {
+          "name": "hide_inactive_beads",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "colored_numerals": {
+          "name": "colored_numerals",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "scale_factor": {
+          "name": "scale_factor",
+          "type": "real",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 1
+        },
+        "show_numbers": {
+          "name": "show_numbers",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": true
+        },
+        "animated": {
+          "name": "animated",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": true
+        },
+        "interactive": {
+          "name": "interactive",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "gestures": {
+          "name": "gestures",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "sound_enabled": {
+          "name": "sound_enabled",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": true
+        },
+        "sound_volume": {
+          "name": "sound_volume",
+          "type": "real",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0.8
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "abacus_settings_user_id_users_id_fk": {
+          "name": "abacus_settings_user_id_users_id_fk",
+          "tableFrom": "abacus_settings",
+          "tableTo": "users",
+          "columnsFrom": ["user_id"],
+          "columnsTo": ["id"],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "arcade_rooms": {
+      "name": "arcade_rooms",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "code": {
+          "name": "code",
+          "type": "text(6)",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "name": {
+          "name": "name",
+          "type": "text(50)",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_by": {
+          "name": "created_by",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "creator_name": {
+          "name": "creator_name",
+          "type": "text(50)",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "last_activity": {
+          "name": "last_activity",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "ttl_minutes": {
+          "name": "ttl_minutes",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 60
+        },
+        "is_locked": {
+          "name": "is_locked",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "game_name": {
+          "name": "game_name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "game_config": {
+          "name": "game_config",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "status": {
+          "name": "status",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'lobby'"
+        },
+        "current_session_id": {
+          "name": "current_session_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "total_games_played": {
+          "name": "total_games_played",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0
+        }
+      },
+      "indexes": {
+        "arcade_rooms_code_unique": {
+          "name": "arcade_rooms_code_unique",
+          "columns": ["code"],
+          "isUnique": true
+        }
+      },
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "arcade_sessions": {
+      "name": "arcade_sessions",
+      "columns": {
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "current_game": {
+          "name": "current_game",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "game_url": {
+          "name": "game_url",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "game_state": {
+          "name": "game_state",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "active_players": {
+          "name": "active_players",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "room_id": {
+          "name": "room_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "started_at": {
+          "name": "started_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "last_activity_at": {
+          "name": "last_activity_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "expires_at": {
+          "name": "expires_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "is_active": {
+          "name": "is_active",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": true
+        },
+        "version": {
+          "name": "version",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 1
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "arcade_sessions_user_id_users_id_fk": {
+          "name": "arcade_sessions_user_id_users_id_fk",
+          "tableFrom": "arcade_sessions",
+          "tableTo": "users",
+          "columnsFrom": ["user_id"],
+          "columnsTo": ["id"],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        },
+        "arcade_sessions_room_id_arcade_rooms_id_fk": {
+          "name": "arcade_sessions_room_id_arcade_rooms_id_fk",
+          "tableFrom": "arcade_sessions",
+          "tableTo": "arcade_rooms",
+          "columnsFrom": ["room_id"],
+          "columnsTo": ["id"],
+          "onDelete": "set null",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "players": {
+      "name": "players",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "emoji": {
+          "name": "emoji",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "color": {
+          "name": "color",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "is_active": {
+          "name": "is_active",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "players_user_id_idx": {
+          "name": "players_user_id_idx",
+          "columns": ["user_id"],
+          "isUnique": false
+        }
+      },
+      "foreignKeys": {
+        "players_user_id_users_id_fk": {
+          "name": "players_user_id_users_id_fk",
+          "tableFrom": "players",
+          "tableTo": "users",
+          "columnsFrom": ["user_id"],
+          "columnsTo": ["id"],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "room_members": {
+      "name": "room_members",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "room_id": {
+          "name": "room_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "display_name": {
+          "name": "display_name",
+          "type": "text(50)",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "is_creator": {
+          "name": "is_creator",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": false
+        },
+        "joined_at": {
+          "name": "joined_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "last_seen": {
+          "name": "last_seen",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "is_online": {
+          "name": "is_online",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": true
+        }
+      },
+      "indexes": {
+        "room_members_user_id_unique": {
+          "name": "room_members_user_id_unique",
+          "columns": ["user_id"],
+          "isUnique": true
+        },
+        "idx_room_members_user_id_unique": {
+          "name": "idx_room_members_user_id_unique",
+          "columns": ["user_id"],
+          "isUnique": true
+        }
+      },
+      "foreignKeys": {
+        "room_members_room_id_arcade_rooms_id_fk": {
+          "name": "room_members_room_id_arcade_rooms_id_fk",
+          "tableFrom": "room_members",
+          "tableTo": "arcade_rooms",
+          "columnsFrom": ["room_id"],
+          "columnsTo": ["id"],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "user_stats": {
+      "name": "user_stats",
+      "columns": {
+        "user_id": {
+          "name": "user_id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "games_played": {
+          "name": "games_played",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0
+        },
+        "total_wins": {
+          "name": "total_wins",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0
+        },
+        "favorite_game_type": {
+          "name": "favorite_game_type",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "best_time": {
+          "name": "best_time",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "highest_accuracy": {
+          "name": "highest_accuracy",
+          "type": "real",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "user_stats_user_id_users_id_fk": {
+          "name": "user_stats_user_id_users_id_fk",
+          "tableFrom": "user_stats",
+          "tableTo": "users",
+          "columnsFrom": ["user_id"],
+          "columnsTo": ["id"],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "users": {
+      "name": "users",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "guest_id": {
+          "name": "guest_id",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "upgraded_at": {
+          "name": "upgraded_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "email": {
+          "name": "email",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "users_guest_id_unique": {
+          "name": "users_guest_id_unique",
+          "columns": ["guest_id"],
+          "isUnique": true
+        },
+        "users_email_unique": {
+          "name": "users_email_unique",
+          "columns": ["email"],
+          "isUnique": true
+        }
+      },
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    }
+  },
+  "views": {},
+  "enums": {},
+  "_meta": {
+    "schemas": {},
+    "tables": {},
+    "columns": {}
+  },
+  "internal": {
+    "indexes": {}
+  }
+}

apps/web/drizzle/meta/_journal.json

@@ -29,6 +29,13 @@
       "when": 1759781243105,
       "tag": "0003_naive_reptil",
       "breakpoints": true
+    },
+    {
+      "idx": 4,
+      "version": "6",
+      "when": 1759930182541,
+      "tag": "0004_shiny_madelyne_pryor",
+      "breakpoints": true
     }
   ]
 }

apps/web/socket-server.js

@@ -1,29 +0,0 @@
-const { Server } = require('socket.io')
-
-function initializeSocketServer(httpServer) {
-  const io = new Server(httpServer, {
-    path: '/api/socket',
-    cors: {
-      origin: process.env.NEXT_PUBLIC_URL || 'http://localhost:3000',
-      credentials: true,
-    },
-  })
-
-  io.on('connection', (socket) => {
-    console.log('🔌 Client connected:', socket.id)
-
-    socket.on('join-arcade-session', ({ userId }) => {
-      socket.join(`arcade:${userId}`)
-      console.log(`👤 User ${userId} joined arcade room`)
-    })
-
-    socket.on('disconnect', () => {
-      console.log('🔌 Client disconnected:', socket.id)
-    })
-  })
-
-  console.log('✅ Socket.IO initialized on /api/socket')
-  return io
-}
-
-module.exports = { initializeSocketServer }

apps/web/socket-server.ts

@@ -1,5 +1,6 @@
 import type { Server as HTTPServer } from 'http'
 import { Server as SocketIOServer } from 'socket.io'
+import type { Server as SocketIOServerType } from 'socket.io'
 import {
   applyGameMove,
   createArcadeSession,
@@ -7,9 +8,26 @@ import {
   getArcadeSession,
   updateSessionActivity,
 } from './src/lib/arcade/session-manager'
-import type { GameMove } from './src/lib/arcade/validation'
+import { createRoom, getRoomById } from './src/lib/arcade/room-manager'
+import { getRoomMembers, getUserRooms, setMemberOnline } from './src/lib/arcade/room-membership'
+import { getRoomActivePlayers } from './src/lib/arcade/player-manager'
+import type { GameMove, GameName } from './src/lib/arcade/validation'
 import { matchingGameValidator } from './src/lib/arcade/validation/MatchingGameValidator'
 
+// Use globalThis to store socket.io instance to avoid module isolation issues
+// This ensures the same instance is accessible across dynamic imports
+declare global {
+  var __socketIO: SocketIOServerType | undefined
+}
+
+/**
+ * Get the socket.io server instance
+ * Returns null if not initialized
+ */
+export function getSocketIO(): SocketIOServerType | null {
+  return globalThis.__socketIO || null
+}
+
 export function initializeSocketServer(httpServer: HTTPServer) {
   const io = new SocketIOServer(httpServer, {
     path: '/api/socket',
@@ -24,30 +42,39 @@ export function initializeSocketServer(httpServer: HTTPServer) {
     let currentUserId: string | null = null
 
     // Join arcade session room
-    socket.on('join-arcade-session', async ({ userId }: { userId: string }) => {
-      currentUserId = userId
-      socket.join(`arcade:${userId}`)
-      console.log(`👤 User ${userId} joined arcade room`)
+    socket.on(
+      'join-arcade-session',
+      async ({ userId, roomId }: { userId: string; roomId?: string }) => {
+        currentUserId = userId
+        socket.join(`arcade:${userId}`)
+        console.log(`👤 User ${userId} joined arcade room`)
 
-      // Send current session state if exists
-      try {
-        const session = await getArcadeSession(userId)
-        if (session) {
-          socket.emit('session-state', {
-            gameState: session.gameState,
-            currentGame: session.currentGame,
-            gameUrl: session.gameUrl,
-            activePlayers: session.activePlayers,
-            version: session.version,
-          })
-        } else {
-          socket.emit('no-active-session')
+        // If this session is part of a room, also join the game room for multi-user sync
+        if (roomId) {
+          socket.join(`game:${roomId}`)
+          console.log(`🎮 User ${userId} joined game room ${roomId}`)
+        }
+
+        // Send current session state if exists
+        try {
+          const session = await getArcadeSession(userId)
+          if (session) {
+            socket.emit('session-state', {
+              gameState: session.gameState,
+              currentGame: session.currentGame,
+              gameUrl: session.gameUrl,
+              activePlayers: session.activePlayers,
+              version: session.version,
+            })
+          } else {
+            socket.emit('no-active-session')
+          }
+        } catch (error) {
+          console.error('Error fetching session:', error)
+          socket.emit('session-error', { error: 'Failed to fetch session' })
         }
-      } catch (error) {
-        console.error('Error fetching session:', error)
-        socket.emit('session-error', { error: 'Failed to fetch session' })
       }
-    })
+    )
 
     // Handle game moves
     socket.on('game-move', async (data: { userId: string; move: GameMove }) => {
@@ -85,20 +112,57 @@ export function initializeSocketServer(httpServer: HTTPServer) {
               turnTimer: 30,
             })
 
+            // Check if user is already in a room for this game
+            const userRoomIds = await getUserRooms(data.userId)
+            let room = null
+
+            // Look for an existing active room for this game
+            for (const roomId of userRoomIds) {
+              const existingRoom = await getRoomById(roomId)
+              if (
+                existingRoom &&
+                existingRoom.gameName === 'matching' &&
+                existingRoom.status !== 'finished'
+              ) {
+                room = existingRoom
+                console.log('🏠 Using existing room:', room.code)
+                break
+              }
+            }
+
+            // If no suitable room exists, create a new one
+            if (!room) {
+              room = await createRoom({
+                name: 'Auto-generated Room',
+                createdBy: data.userId,
+                creatorName: 'Player',
+                gameName: 'matching' as GameName,
+                gameConfig: {
+                  difficulty: 6,
+                  gameType: 'abacus-numeral',
+                  turnTimer: 30,
+                },
+                ttlMinutes: 60,
+              })
+              console.log('🏠 Created new room:', room.code)
+            }
+
+            // Now create the session linked to the room
             await createArcadeSession({
               userId: data.userId,
               gameName: 'matching',
-              gameUrl: '/arcade/matching',
+              gameUrl: '/arcade/room', // Room-based sessions use /arcade/room
               initialState,
               activePlayers,
+              roomId: room.id,
             })
 
-            console.log('✅ Session created successfully')
+            console.log('✅ Session created successfully with room association')
 
             // Notify all connected clients about the new session
             const newSession = await getArcadeSession(data.userId)
             if (newSession) {
-              io.to(`arcade:${data.userId}`).emit('session-state', {
+              io!.to(`arcade:${data.userId}`).emit('session-state', {
                 gameState: newSession.gameState,
                 currentGame: newSession.currentGame,
                 gameUrl: newSession.gameUrl,
@@ -113,12 +177,20 @@ export function initializeSocketServer(httpServer: HTTPServer) {
         const result = await applyGameMove(data.userId, data.move)
 
         if (result.success && result.session) {
-          // Broadcast the updated state to all devices for this user
-          io.to(`arcade:${data.userId}`).emit('move-accepted', {
+          const moveAcceptedData = {
             gameState: result.session.gameState,
             version: result.session.version,
             move: data.move,
-          })
+          }
+
+          // Broadcast the updated state to all devices for this user
+          io!.to(`arcade:${data.userId}`).emit('move-accepted', moveAcceptedData)
+
+          // If this is a room-based session, ALSO broadcast to all users in the room
+          if (result.session.roomId) {
+            io!.to(`game:${result.session.roomId}`).emit('move-accepted', moveAcceptedData)
+            console.log(`📢 Broadcasted move to game room ${result.session.roomId}`)
+          }
 
           // Update activity timestamp
           await updateSessionActivity(data.userId)
@@ -145,7 +217,7 @@ export function initializeSocketServer(httpServer: HTTPServer) {
 
       try {
         await deleteArcadeSession(userId)
-        io.to(`arcade:${userId}`).emit('session-ended')
+        io!.to(`arcade:${userId}`).emit('session-ended')
       } catch (error) {
         console.error('Error ending session:', error)
         socket.emit('session-error', { error: 'Failed to end session' })
@@ -162,6 +234,111 @@ export function initializeSocketServer(httpServer: HTTPServer) {
       }
     })
 
+    // Room: Join
+    socket.on('join-room', async ({ roomId, userId }: { roomId: string; userId: string }) => {
+      console.log(`🏠 User ${userId} joining room ${roomId}`)
+
+      try {
+        // Join the socket room
+        socket.join(`room:${roomId}`)
+
+        // Mark member as online
+        await setMemberOnline(roomId, userId, true)
+
+        // Get room data
+        const members = await getRoomMembers(roomId)
+        const memberPlayers = await getRoomActivePlayers(roomId)
+
+        // Convert memberPlayers Map to object for JSON serialization
+        const memberPlayersObj: Record<string, any[]> = {}
+        for (const [uid, players] of memberPlayers.entries()) {
+          memberPlayersObj[uid] = players
+        }
+
+        // Send current room state to the joining user
+        socket.emit('room-joined', {
+          roomId,
+          members,
+          memberPlayers: memberPlayersObj,
+        })
+
+        // Notify all other members in the room
+        socket.to(`room:${roomId}`).emit('member-joined', {
+          roomId,
+          userId,
+          members,
+          memberPlayers: memberPlayersObj,
+        })
+
+        console.log(`✅ User ${userId} joined room ${roomId}`)
+      } catch (error) {
+        console.error('Error joining room:', error)
+        socket.emit('room-error', { error: 'Failed to join room' })
+      }
+    })
+
+    // Room: Leave
+    socket.on('leave-room', async ({ roomId, userId }: { roomId: string; userId: string }) => {
+      console.log(`🚪 User ${userId} leaving room ${roomId}`)
+
+      try {
+        // Leave the socket room
+        socket.leave(`room:${roomId}`)
+
+        // Mark member as offline
+        await setMemberOnline(roomId, userId, false)
+
+        // Get updated members
+        const members = await getRoomMembers(roomId)
+        const memberPlayers = await getRoomActivePlayers(roomId)
+
+        // Convert memberPlayers Map to object
+        const memberPlayersObj: Record<string, any[]> = {}
+        for (const [uid, players] of memberPlayers.entries()) {
+          memberPlayersObj[uid] = players
+        }
+
+        // Notify remaining members
+        io!.to(`room:${roomId}`).emit('member-left', {
+          roomId,
+          userId,
+          members,
+          memberPlayers: memberPlayersObj,
+        })
+
+        console.log(`✅ User ${userId} left room ${roomId}`)
+      } catch (error) {
+        console.error('Error leaving room:', error)
+      }
+    })
+
+    // Room: Players updated
+    socket.on('players-updated', async ({ roomId, userId }: { roomId: string; userId: string }) => {
+      console.log(`🎯 Players updated for user ${userId} in room ${roomId}`)
+
+      try {
+        // Get updated player data
+        const memberPlayers = await getRoomActivePlayers(roomId)
+
+        // Convert memberPlayers Map to object
+        const memberPlayersObj: Record<string, any[]> = {}
+        for (const [uid, players] of memberPlayers.entries()) {
+          memberPlayersObj[uid] = players
+        }
+
+        // Broadcast to all members in the room (including sender)
+        io!.to(`room:${roomId}`).emit('room-players-updated', {
+          roomId,
+          memberPlayers: memberPlayersObj,
+        })
+
+        console.log(`✅ Broadcasted player updates for room ${roomId}`)
+      } catch (error) {
+        console.error('Error updating room players:', error)
+        socket.emit('room-error', { error: 'Failed to update players' })
+      }
+    })
+
     socket.on('disconnect', () => {
       console.log('🔌 Client disconnected:', socket.id)
       if (currentUserId) {
@@ -171,6 +348,8 @@ export function initializeSocketServer(httpServer: HTTPServer) {
     })
   })
 
+  // Store in globalThis to make accessible across module boundaries
+  globalThis.__socketIO = io
   console.log('✅ Socket.IO initialized on /api/socket')
   return io
 }

apps/web/src/app/api/arcade-session/route.ts

@@ -47,10 +47,16 @@ export async function GET(request: NextRequest) {
 export async function POST(request: NextRequest) {
   try {
     const body = await request.json()
-    const { userId, gameName, gameUrl, initialState, activePlayers } = body
+    const { userId, gameName, gameUrl, initialState, activePlayers, roomId } = body
 
-    if (!userId || !gameName || !gameUrl || !initialState || !activePlayers) {
-      return NextResponse.json({ error: 'Missing required fields' }, { status: 400 })
+    if (!userId || !gameName || !gameUrl || !initialState || !activePlayers || !roomId) {
+      return NextResponse.json(
+        {
+          error:
+            'Missing required fields (userId, gameName, gameUrl, initialState, activePlayers, roomId)',
+        },
+        { status: 400 }
+      )
     }
 
     const session = await createArcadeSession({
@@ -59,6 +65,7 @@ export async function POST(request: NextRequest) {
       gameUrl,
       initialState,
       activePlayers,
+      roomId,
     })
 
     return NextResponse.json({

apps/web/src/app/api/arcade/rooms/[roomId]/join/route.ts

@@ -0,0 +1,125 @@
+import { type NextRequest, NextResponse } from 'next/server'
+import { getRoomById, touchRoom } from '@/lib/arcade/room-manager'
+import { addRoomMember, getRoomMembers } from '@/lib/arcade/room-membership'
+import { getActivePlayers, getRoomActivePlayers } from '@/lib/arcade/player-manager'
+import { getViewerId } from '@/lib/viewer'
+import { getSocketIO } from '@/lib/socket-io'
+
+type RouteContext = {
+  params: Promise<{ roomId: string }>
+}
+
+/**
+ * POST /api/arcade/rooms/:roomId/join
+ * Join a room
+ * Body:
+ *   - displayName?: string (optional, will generate from viewerId if not provided)
+ */
+export async function POST(req: NextRequest, context: RouteContext) {
+  try {
+    const { roomId } = await context.params
+    const viewerId = await getViewerId()
+    const body = await req.json().catch(() => ({}))
+
+    // Get room
+    const room = await getRoomById(roomId)
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 })
+    }
+
+    // Check if room is locked
+    if (room.isLocked) {
+      return NextResponse.json({ error: 'Room is locked' }, { status: 403 })
+    }
+
+    // Get or generate display name
+    const displayName = body.displayName || `Guest ${viewerId.slice(-4)}`
+
+    // Validate display name length
+    if (displayName.length > 50) {
+      return NextResponse.json(
+        { error: 'Display name too long (max 50 characters)' },
+        { status: 400 }
+      )
+    }
+
+    // Add member (with auto-leave logic for modal room enforcement)
+    const { member, autoLeaveResult } = await addRoomMember({
+      roomId,
+      userId: viewerId,
+      displayName,
+      isCreator: false,
+    })
+
+    // Fetch user's active players (these will participate in the game)
+    const activePlayers = await getActivePlayers(viewerId)
+
+    // Update room activity to refresh TTL
+    await touchRoom(roomId)
+
+    // Broadcast to all users in the room via socket
+    const io = await getSocketIO()
+    if (io) {
+      try {
+        const members = await getRoomMembers(roomId)
+        const memberPlayers = await getRoomActivePlayers(roomId)
+
+        // Convert memberPlayers Map to object for JSON serialization
+        const memberPlayersObj: Record<string, any[]> = {}
+        for (const [uid, players] of memberPlayers.entries()) {
+          memberPlayersObj[uid] = players
+        }
+
+        // Broadcast to all users in this room
+        io.to(`room:${roomId}`).emit('member-joined', {
+          roomId,
+          userId: viewerId,
+          members,
+          memberPlayers: memberPlayersObj,
+        })
+
+        console.log(`[Join API] Broadcasted member-joined for user ${viewerId} in room ${roomId}`)
+      } catch (socketError) {
+        // Log but don't fail the request if socket broadcast fails
+        console.error('[Join API] Failed to broadcast member-joined:', socketError)
+      }
+    }
+
+    // Build response with auto-leave info if applicable
+    return NextResponse.json(
+      {
+        member,
+        room,
+        activePlayers, // The user's active players that will join the game
+        autoLeave: autoLeaveResult
+          ? {
+              leftRooms: autoLeaveResult.leftRooms,
+              roomCount: autoLeaveResult.leftRooms.length,
+              message: `You were automatically removed from ${autoLeaveResult.leftRooms.length} other room(s)`,
+            }
+          : undefined,
+      },
+      { status: 201 }
+    )
+  } catch (error: any) {
+    console.error('Failed to join room:', error)
+
+    // Handle specific constraint violation error
+    if (error.message?.includes('ROOM_MEMBERSHIP_CONFLICT')) {
+      return NextResponse.json(
+        {
+          error: 'You are already in another room',
+          code: 'ROOM_MEMBERSHIP_CONFLICT',
+          message:
+            'You can only be in one room at a time. Please leave your current room before joining a new one.',
+          userMessage:
+            '⚠️ Already in Another Room\n\nYou can only be in one room at a time. Please refresh the page and try again.',
+        },
+        { status: 409 } // 409 Conflict
+      )
+    }
+
+    // Generic error
+    return NextResponse.json({ error: 'Failed to join room' }, { status: 500 })
+  }
+}

apps/web/src/app/api/arcade/rooms/[roomId]/leave/route.ts

@@ -0,0 +1,69 @@
+import { type NextRequest, NextResponse } from 'next/server'
+import { getRoomById } from '@/lib/arcade/room-manager'
+import { getRoomMembers, isMember, removeMember } from '@/lib/arcade/room-membership'
+import { getRoomActivePlayers } from '@/lib/arcade/player-manager'
+import { getViewerId } from '@/lib/viewer'
+import { getSocketIO } from '@/lib/socket-io'
+
+type RouteContext = {
+  params: Promise<{ roomId: string }>
+}
+
+/**
+ * POST /api/arcade/rooms/:roomId/leave
+ * Leave a room
+ */
+export async function POST(_req: NextRequest, context: RouteContext) {
+  try {
+    const { roomId } = await context.params
+    const viewerId = await getViewerId()
+
+    // Get room
+    const room = await getRoomById(roomId)
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 })
+    }
+
+    // Check if member
+    const isMemberOfRoom = await isMember(roomId, viewerId)
+    if (!isMemberOfRoom) {
+      return NextResponse.json({ error: 'Not a member of this room' }, { status: 400 })
+    }
+
+    // Remove member
+    await removeMember(roomId, viewerId)
+
+    // Broadcast to all remaining users in the room via socket
+    const io = await getSocketIO()
+    if (io) {
+      try {
+        const members = await getRoomMembers(roomId)
+        const memberPlayers = await getRoomActivePlayers(roomId)
+
+        // Convert memberPlayers Map to object for JSON serialization
+        const memberPlayersObj: Record<string, any[]> = {}
+        for (const [uid, players] of memberPlayers.entries()) {
+          memberPlayersObj[uid] = players
+        }
+
+        // Broadcast to all users in this room
+        io.to(`room:${roomId}`).emit('member-left', {
+          roomId,
+          userId: viewerId,
+          members,
+          memberPlayers: memberPlayersObj,
+        })
+
+        console.log(`[Leave API] Broadcasted member-left for user ${viewerId} in room ${roomId}`)
+      } catch (socketError) {
+        // Log but don't fail the request if socket broadcast fails
+        console.error('[Leave API] Failed to broadcast member-left:', socketError)
+      }
+    }
+
+    return NextResponse.json({ success: true })
+  } catch (error) {
+    console.error('Failed to leave room:', error)
+    return NextResponse.json({ error: 'Failed to leave room' }, { status: 500 })
+  }
+}

apps/web/src/app/api/arcade/rooms/[roomId]/members/[userId]/route.ts

@@ -0,0 +1,50 @@
+import { type NextRequest, NextResponse } from 'next/server'
+import { getRoomById, isRoomCreator } from '@/lib/arcade/room-manager'
+import { isMember, removeMember } from '@/lib/arcade/room-membership'
+import { getViewerId } from '@/lib/viewer'
+
+type RouteContext = {
+  params: Promise<{ roomId: string; userId: string }>
+}
+
+/**
+ * DELETE /api/arcade/rooms/:roomId/members/:userId
+ * Kick a member from room (creator only)
+ */
+export async function DELETE(_req: NextRequest, context: RouteContext) {
+  try {
+    const { roomId, userId } = await context.params
+    const viewerId = await getViewerId()
+
+    // Get room
+    const room = await getRoomById(roomId)
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 })
+    }
+
+    // Check if requester is room creator
+    const isCreator = await isRoomCreator(roomId, viewerId)
+    if (!isCreator) {
+      return NextResponse.json({ error: 'Only room creator can kick members' }, { status: 403 })
+    }
+
+    // Cannot kick self
+    if (userId === viewerId) {
+      return NextResponse.json({ error: 'Cannot kick yourself' }, { status: 400 })
+    }
+
+    // Check if target user is a member
+    const isTargetMember = await isMember(roomId, userId)
+    if (!isTargetMember) {
+      return NextResponse.json({ error: 'User is not a member of this room' }, { status: 404 })
+    }
+
+    // Remove member
+    await removeMember(roomId, userId)
+
+    return NextResponse.json({ success: true })
+  } catch (error) {
+    console.error('Failed to kick member:', error)
+    return NextResponse.json({ error: 'Failed to kick member' }, { status: 500 })
+  }
+}

apps/web/src/app/api/arcade/rooms/[roomId]/members/route.ts

@@ -0,0 +1,35 @@
+import { type NextRequest, NextResponse } from 'next/server'
+import { getRoomById } from '@/lib/arcade/room-manager'
+import { getOnlineMemberCount, getRoomMembers } from '@/lib/arcade/room-membership'
+
+type RouteContext = {
+  params: Promise<{ roomId: string }>
+}
+
+/**
+ * GET /api/arcade/rooms/:roomId/members
+ * Get all members in a room
+ */
+export async function GET(_req: NextRequest, context: RouteContext) {
+  try {
+    const { roomId } = await context.params
+
+    // Get room
+    const room = await getRoomById(roomId)
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 })
+    }
+
+    // Get members
+    const members = await getRoomMembers(roomId)
+    const onlineCount = await getOnlineMemberCount(roomId)
+
+    return NextResponse.json({
+      members,
+      onlineCount,
+    })
+  } catch (error) {
+    console.error('Failed to fetch members:', error)
+    return NextResponse.json({ error: 'Failed to fetch members' }, { status: 500 })
+  }
+}

apps/web/src/app/api/arcade/rooms/[roomId]/route.ts

@@ -0,0 +1,132 @@
+import { type NextRequest, NextResponse } from 'next/server'
+import {
+  deleteRoom,
+  getRoomById,
+  isRoomCreator,
+  touchRoom,
+  updateRoom,
+} from '@/lib/arcade/room-manager'
+import { getRoomMembers } from '@/lib/arcade/room-membership'
+import { getActivePlayers } from '@/lib/arcade/player-manager'
+import { getViewerId } from '@/lib/viewer'
+
+type RouteContext = {
+  params: Promise<{ roomId: string }>
+}
+
+/**
+ * GET /api/arcade/rooms/:roomId
+ * Get room details including members
+ */
+export async function GET(_req: NextRequest, context: RouteContext) {
+  try {
+    const { roomId } = await context.params
+    const viewerId = await getViewerId()
+
+    const room = await getRoomById(roomId)
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 })
+    }
+
+    const members = await getRoomMembers(roomId)
+    const canModerate = await isRoomCreator(roomId, viewerId)
+
+    // Fetch active players for each member
+    // This creates a map of userId -> Player[]
+    const memberPlayers: Record<string, any[]> = {}
+    for (const member of members) {
+      const activePlayers = await getActivePlayers(member.userId)
+      memberPlayers[member.userId] = activePlayers
+    }
+
+    // Update room activity when viewing (keeps active rooms fresh)
+    await touchRoom(roomId)
+
+    return NextResponse.json({
+      room,
+      members,
+      memberPlayers, // Map of userId -> active Player[] for each member
+      canModerate,
+    })
+  } catch (error) {
+    console.error('Failed to fetch room:', error)
+    return NextResponse.json({ error: 'Failed to fetch room' }, { status: 500 })
+  }
+}
+
+/**
+ * PATCH /api/arcade/rooms/:roomId
+ * Update room (creator only)
+ * Body:
+ *   - name?: string
+ *   - isLocked?: boolean
+ *   - status?: 'lobby' | 'playing' | 'finished'
+ */
+export async function PATCH(req: NextRequest, context: RouteContext) {
+  try {
+    const { roomId } = await context.params
+    const viewerId = await getViewerId()
+    const body = await req.json()
+
+    // Check if user is room creator
+    const isCreator = await isRoomCreator(roomId, viewerId)
+    if (!isCreator) {
+      return NextResponse.json({ error: 'Only room creator can update room' }, { status: 403 })
+    }
+
+    // Validate name length if provided
+    if (body.name && body.name.length > 50) {
+      return NextResponse.json({ error: 'Room name too long (max 50 characters)' }, { status: 400 })
+    }
+
+    // Validate status if provided
+    if (body.status && !['lobby', 'playing', 'finished'].includes(body.status)) {
+      return NextResponse.json({ error: 'Invalid status' }, { status: 400 })
+    }
+
+    const updates: {
+      name?: string
+      isLocked?: boolean
+      status?: 'lobby' | 'playing' | 'finished'
+    } = {}
+
+    if (body.name !== undefined) updates.name = body.name
+    if (body.isLocked !== undefined) updates.isLocked = body.isLocked
+    if (body.status !== undefined) updates.status = body.status
+
+    const room = await updateRoom(roomId, updates)
+
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 })
+    }
+
+    return NextResponse.json({ room })
+  } catch (error) {
+    console.error('Failed to update room:', error)
+    return NextResponse.json({ error: 'Failed to update room' }, { status: 500 })
+  }
+}
+
+/**
+ * DELETE /api/arcade/rooms/:roomId
+ * Delete room (creator only)
+ */
+export async function DELETE(_req: NextRequest, context: RouteContext) {
+  try {
+    const { roomId } = await context.params
+    const viewerId = await getViewerId()
+
+    // Check if user is room creator
+    const isCreator = await isRoomCreator(roomId, viewerId)
+    if (!isCreator) {
+      return NextResponse.json({ error: 'Only room creator can delete room' }, { status: 403 })
+    }
+
+    await deleteRoom(roomId)
+
+    return NextResponse.json({ success: true })
+  } catch (error) {
+    console.error('Failed to delete room:', error)
+    return NextResponse.json({ error: 'Failed to delete room' }, { status: 500 })
+  }
+}

apps/web/src/app/api/arcade/rooms/code/[code]/route.ts

@@ -0,0 +1,39 @@
+import { type NextRequest, NextResponse } from 'next/server'
+import { getRoomByCode } from '@/lib/arcade/room-manager'
+import { normalizeRoomCode } from '@/lib/arcade/room-code'
+
+type RouteContext = {
+  params: Promise<{ code: string }>
+}
+
+/**
+ * GET /api/arcade/rooms/code/:code
+ * Get room by join code (for resolving codes to room IDs)
+ */
+export async function GET(_req: NextRequest, context: RouteContext) {
+  try {
+    const { code } = await context.params
+
+    // Normalize the code (uppercase, remove spaces/dashes)
+    const normalizedCode = normalizeRoomCode(code)
+
+    // Get room
+    const room = await getRoomByCode(normalizedCode)
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 })
+    }
+
+    // Generate redirect URL
+    const baseUrl = process.env.NEXT_PUBLIC_URL || 'http://localhost:3000'
+    const redirectUrl = `${baseUrl}/arcade/rooms/${room.id}`
+
+    return NextResponse.json({
+      roomId: room.id,
+      redirectUrl,
+      room,
+    })
+  } catch (error) {
+    console.error('Failed to find room by code:', error)
+    return NextResponse.json({ error: 'Failed to find room by code' }, { status: 500 })
+  }
+}

apps/web/src/app/api/arcade/rooms/current/route.ts

@@ -0,0 +1,52 @@
+import { NextResponse } from 'next/server'
+import { getUserRooms } from '@/lib/arcade/room-membership'
+import { getRoomById } from '@/lib/arcade/room-manager'
+import { getRoomMembers } from '@/lib/arcade/room-membership'
+import { getRoomActivePlayers } from '@/lib/arcade/player-manager'
+import { getViewerId } from '@/lib/viewer'
+
+/**
+ * GET /api/arcade/rooms/current
+ * Returns the user's current room (if any)
+ */
+export async function GET() {
+  try {
+    const userId = await getViewerId()
+
+    // Get all rooms user is in (should be at most 1 due to modal room enforcement)
+    const roomIds = await getUserRooms(userId)
+
+    if (roomIds.length === 0) {
+      return NextResponse.json({ room: null }, { status: 200 })
+    }
+
+    const roomId = roomIds[0]
+
+    // Get room data
+    const room = await getRoomById(roomId)
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 })
+    }
+
+    // Get members
+    const members = await getRoomMembers(roomId)
+
+    // Get active players for all members
+    const memberPlayers = await getRoomActivePlayers(roomId)
+
+    // Convert Map to object for JSON serialization
+    const memberPlayersObj: Record<string, any[]> = {}
+    for (const [uid, players] of memberPlayers.entries()) {
+      memberPlayersObj[uid] = players
+    }
+
+    return NextResponse.json({
+      room,
+      members,
+      memberPlayers: memberPlayersObj,
+    })
+  } catch (error) {
+    console.error('[Current Room API] Error:', error)
+    return NextResponse.json({ error: 'Failed to fetch current room' }, { status: 500 })
+  }
+}

apps/web/src/app/api/arcade/rooms/route.ts

@@ -0,0 +1,126 @@
+import { type NextRequest, NextResponse } from 'next/server'
+import { createRoom, listActiveRooms } from '@/lib/arcade/room-manager'
+import { addRoomMember, getRoomMembers, isMember } from '@/lib/arcade/room-membership'
+import { getRoomActivePlayers } from '@/lib/arcade/player-manager'
+import { getViewerId } from '@/lib/viewer'
+import type { GameName } from '@/lib/arcade/validation'
+
+/**
+ * GET /api/arcade/rooms
+ * List all active public rooms (lobby view)
+ * Query params:
+ *   - gameName?: string - Filter by game
+ */
+export async function GET(req: NextRequest) {
+  try {
+    const { searchParams } = new URL(req.url)
+    const gameName = searchParams.get('gameName') as GameName | null
+
+    const viewerId = await getViewerId()
+    const rooms = await listActiveRooms(gameName || undefined)
+
+    // Enrich with member counts, player counts, and membership status
+    const roomsWithCounts = await Promise.all(
+      rooms.map(async (room) => {
+        const members = await getRoomMembers(room.id)
+        const playerMap = await getRoomActivePlayers(room.id)
+        const userIsMember = await isMember(room.id, viewerId)
+
+        let totalPlayers = 0
+        for (const players of playerMap.values()) {
+          totalPlayers += players.length
+        }
+
+        return {
+          id: room.id,
+          name: room.name,
+          code: room.code,
+          gameName: room.gameName,
+          status: room.status,
+          createdAt: room.createdAt,
+          creatorName: room.creatorName,
+          isLocked: room.isLocked,
+          memberCount: members.length,
+          playerCount: totalPlayers,
+          isMember: userIsMember,
+        }
+      })
+    )
+
+    return NextResponse.json({ rooms: roomsWithCounts })
+  } catch (error) {
+    console.error('Failed to fetch rooms:', error)
+    return NextResponse.json({ error: 'Failed to fetch rooms' }, { status: 500 })
+  }
+}
+
+/**
+ * POST /api/arcade/rooms
+ * Create a new room
+ * Body:
+ *   - name: string
+ *   - gameName: string
+ *   - gameConfig?: object
+ *   - ttlMinutes?: number
+ */
+export async function POST(req: NextRequest) {
+  try {
+    const viewerId = await getViewerId()
+    const body = await req.json()
+
+    // Validate required fields
+    if (!body.name || !body.gameName) {
+      return NextResponse.json(
+        { error: 'Missing required fields: name, gameName' },
+        { status: 400 }
+      )
+    }
+
+    // Validate game name
+    const validGames: GameName[] = ['matching', 'memory-quiz', 'complement-race']
+    if (!validGames.includes(body.gameName)) {
+      return NextResponse.json({ error: 'Invalid game name' }, { status: 400 })
+    }
+
+    // Validate name length
+    if (body.name.length > 50) {
+      return NextResponse.json({ error: 'Room name too long (max 50 characters)' }, { status: 400 })
+    }
+
+    // Get display name from body or generate from viewerId
+    const displayName = body.creatorName || `Guest ${viewerId.slice(-4)}`
+
+    // Create room
+    const room = await createRoom({
+      name: body.name,
+      createdBy: viewerId,
+      creatorName: displayName,
+      gameName: body.gameName,
+      gameConfig: body.gameConfig || {},
+      ttlMinutes: body.ttlMinutes,
+    })
+
+    // Add creator as first member
+    await addRoomMember({
+      roomId: room.id,
+      userId: viewerId,
+      displayName,
+      isCreator: true,
+    })
+
+    // Generate join URL
+    const baseUrl = process.env.NEXT_PUBLIC_URL || 'http://localhost:3000'
+    const joinUrl = `${baseUrl}/arcade/rooms/${room.id}`
+
+    return NextResponse.json(
+      {
+        room,
+        joinUrl,
+      },
+      { status: 201 }
+    )
+  } catch (error) {
+    console.error('Failed to create room:', error)
+    return NextResponse.json({ error: 'Failed to create room' }, { status: 500 })
+  }
+}

apps/web/src/app/api/debug/active-players/route.ts

@@ -0,0 +1,57 @@
+import { NextResponse } from 'next/server'
+import { getViewerId } from '@/lib/viewer'
+import { getActivePlayers } from '@/lib/arcade/player-manager'
+import { db, schema } from '@/db'
+import { eq } from 'drizzle-orm'
+
+/**
+ * GET /api/debug/active-players
+ * Debug endpoint to check active players for current user
+ */
+export async function GET() {
+  try {
+    const viewerId = await getViewerId()
+
+    // Get user record
+    const user = await db.query.users.findFirst({
+      where: eq(schema.users.guestId, viewerId),
+    })
+
+    if (!user) {
+      return NextResponse.json({ error: 'User not found', viewerId }, { status: 404 })
+    }
+
+    // Get ALL players for this user
+    const allPlayers = await db.query.players.findMany({
+      where: eq(schema.players.userId, user.id),
+    })
+
+    // Get active players using the helper
+    const activePlayers = await getActivePlayers(viewerId)
+
+    return NextResponse.json({
+      viewerId,
+      userId: user.id,
+      allPlayers: allPlayers.map((p) => ({
+        id: p.id,
+        name: p.name,
+        emoji: p.emoji,
+        isActive: p.isActive,
+      })),
+      activePlayers: activePlayers.map((p) => ({
+        id: p.id,
+        name: p.name,
+        emoji: p.emoji,
+        isActive: p.isActive,
+      })),
+      activeCount: activePlayers.length,
+      totalCount: allPlayers.length,
+    })
+  } catch (error) {
+    console.error('Failed to fetch active players:', error)
+    return NextResponse.json(
+      { error: 'Failed to fetch active players', details: String(error) },
+      { status: 500 }
+    )
+  }
+}

apps/web/src/app/arcade-rooms/[roomId]/page.tsx

@@ -0,0 +1,665 @@
+'use client'
+
+import { useEffect, useState } from 'react'
+import { useParams, useRouter } from 'next/navigation'
+import { io, type Socket } from 'socket.io-client'
+import { css } from '../../../../styled-system/css'
+import { PageWithNav } from '@/components/PageWithNav'
+import { useViewerId } from '@/hooks/useViewerId'
+
+interface Room {
+  id: string
+  code: string
+  name: string
+  gameName: string
+  status: 'lobby' | 'playing' | 'finished'
+  createdBy: string
+  creatorName: string
+  isLocked: boolean
+}
+
+interface Member {
+  id: string
+  userId: string
+  displayName: string
+  isCreator: boolean
+  isOnline: boolean
+  joinedAt: Date
+}
+
+interface Player {
+  id: string
+  userId: string
+  name: string
+  emoji: string
+  color: string
+  isActive: boolean
+}
+
+export default function RoomDetailPage() {
+  const params = useParams()
+  const router = useRouter()
+  const roomId = params.roomId as string
+  const { data: guestId } = useViewerId()
+
+  const [room, setRoom] = useState<Room | null>(null)
+  const [members, setMembers] = useState<Member[]>([])
+  const [memberPlayers, setMemberPlayers] = useState<Record<string, Player[]>>({})
+  const [loading, setLoading] = useState(true)
+  const [error, setError] = useState<string | null>(null)
+  const [socket, setSocket] = useState<Socket | null>(null)
+  const [isConnected, setIsConnected] = useState(false)
+
+  useEffect(() => {
+    fetchRoom()
+  }, [roomId])
+
+  useEffect(() => {
+    if (!guestId || !roomId) return
+
+    // Connect to socket
+    const sock = io({ path: '/api/socket' })
+    setSocket(sock)
+
+    sock.on('connect', () => {
+      setIsConnected(true)
+      // Join the room
+      sock.emit('join-room', { roomId, userId: guestId })
+    })
+
+    sock.on('disconnect', () => {
+      setIsConnected(false)
+    })
+
+    sock.on('room-joined', (data) => {
+      console.log('Joined room:', data)
+      if (data.members) {
+        setMembers(data.members)
+      }
+      if (data.memberPlayers) {
+        setMemberPlayers(data.memberPlayers)
+      }
+    })
+
+    sock.on('member-joined', (data) => {
+      console.log('Member joined:', data)
+      if (data.members) {
+        setMembers(data.members)
+      }
+      if (data.memberPlayers) {
+        setMemberPlayers(data.memberPlayers)
+      }
+    })
+
+    sock.on('member-left', (data) => {
+      console.log('Member left:', data)
+      if (data.members) {
+        setMembers(data.members)
+      }
+      if (data.memberPlayers) {
+        setMemberPlayers(data.memberPlayers)
+      }
+    })
+
+    sock.on('room-error', (error) => {
+      console.error('Room error:', error)
+      setError(error.error)
+    })
+
+    sock.on('room-players-updated', (data) => {
+      console.log('Room players updated:', data)
+      if (data.memberPlayers) {
+        setMemberPlayers(data.memberPlayers)
+      }
+    })
+
+    return () => {
+      sock.emit('leave-room', { roomId, userId: guestId })
+      sock.disconnect()
+    }
+  }, [roomId, guestId])
+
+  // Notify room when window regains focus (user might have changed players in another tab)
+  useEffect(() => {
+    if (!socket || !guestId || !roomId) return
+
+    const handleFocus = () => {
+      console.log('Window focused, notifying room of potential player changes')
+      socket.emit('players-updated', { roomId, userId: guestId })
+    }
+
+    window.addEventListener('focus', handleFocus)
+    return () => window.removeEventListener('focus', handleFocus)
+  }, [socket, roomId, guestId])
+
+  const fetchRoom = async () => {
+    try {
+      setLoading(true)
+      const response = await fetch(`/api/arcade/rooms/${roomId}`)
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status}`)
+      }
+      const data = await response.json()
+      setRoom(data.room)
+      setMembers(data.members || [])
+      setMemberPlayers(data.memberPlayers || {})
+      setError(null)
+    } catch (err) {
+      console.error('Failed to fetch room:', err)
+      setError('Failed to load room')
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  const startGame = () => {
+    if (!room) return
+    // Navigate to the room game page
+    router.push('/arcade/room')
+  }
+
+  const joinRoom = async () => {
+    try {
+      const response = await fetch(`/api/arcade/rooms/${roomId}/join`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ displayName: 'Player' }),
+      })
+
+      if (!response.ok) {
+        const errorData = await response.json()
+
+        // Handle specific room membership conflict
+        if (errorData.code === 'ROOM_MEMBERSHIP_CONFLICT') {
+          alert(errorData.userMessage || errorData.message)
+          // Refresh the page to update room state
+          await fetchRoom()
+          return
+        }
+
+        throw new Error(errorData.error || `HTTP ${response.status}`)
+      }
+
+      const data = await response.json()
+
+      // Show notification if user was auto-removed from other rooms
+      if (data.autoLeave) {
+        console.log(`[Room Join] ${data.autoLeave.message}`)
+        // Could show a toast notification here in the future
+      }
+
+      // Refresh room data to update membership UI
+      await fetchRoom()
+    } catch (err) {
+      console.error('Failed to join room:', err)
+      alert('Failed to join room')
+    }
+  }
+
+  const leaveRoom = async () => {
+    try {
+      const response = await fetch(`/api/arcade/rooms/${roomId}/leave`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+      })
+
+      if (!response.ok) {
+        const errorData = await response.json()
+        throw new Error(errorData.error || `HTTP ${response.status}`)
+      }
+
+      // Navigate to arcade home after successfully leaving
+      router.push('/arcade')
+    } catch (err) {
+      console.error('Failed to leave room:', err)
+      alert('Failed to leave room')
+    }
+  }
+
+  if (loading) {
+    return (
+      <PageWithNav>
+        <div
+          className={css({
+            minH: 'calc(100vh - 80px)',
+            bg: 'linear-gradient(135deg, #0f0f23 0%, #1a1a3a 50%, #2d1b69 100%)',
+            display: 'flex',
+            alignItems: 'center',
+            justifyContent: 'center',
+            color: 'white',
+            fontSize: 'xl',
+          })}
+        >
+          Loading room...
+        </div>
+      </PageWithNav>
+    )
+  }
+
+  if (error || !room) {
+    return (
+      <PageWithNav>
+        <div
+          className={css({
+            minH: 'calc(100vh - 80px)',
+            bg: 'linear-gradient(135deg, #0f0f23 0%, #1a1a3a 50%, #2d1b69 100%)',
+            display: 'flex',
+            alignItems: 'center',
+            justifyContent: 'center',
+            p: '8',
+          })}
+        >
+          <div
+            className={css({
+              bg: 'rgba(255, 255, 255, 0.05)',
+              backdropFilter: 'blur(10px)',
+              border: '1px solid rgba(255, 255, 255, 0.1)',
+              rounded: 'lg',
+              p: '12',
+              textAlign: 'center',
+              maxW: '500px',
+            })}
+          >
+            <p className={css({ fontSize: 'xl', color: 'white', mb: '4' })}>
+              {error || 'Room not found'}
+            </p>
+            <button
+              onClick={() => router.push('/arcade-rooms')}
+              className={css({
+                px: '6',
+                py: '3',
+                bg: '#3b82f6',
+                color: 'white',
+                rounded: 'lg',
+                fontWeight: '600',
+                cursor: 'pointer',
+                _hover: { bg: '#2563eb' },
+              })}
+            >
+              Back to Rooms
+            </button>
+          </div>
+        </div>
+      </PageWithNav>
+    )
+  }
+
+  const onlineMembers = members.filter((m) => m.isOnline)
+
+  // Check if current user is a member
+  const isMember = members.some((m) => m.userId === guestId)
+
+  // Calculate union of all active players in the room
+  const allPlayers: Player[] = []
+  const playerIds = new Set<string>()
+
+  for (const userId in memberPlayers) {
+    for (const player of memberPlayers[userId]) {
+      if (!playerIds.has(player.id)) {
+        playerIds.add(player.id)
+        allPlayers.push(player)
+      }
+    }
+  }
+
+  return (
+    <PageWithNav>
+      <div
+        className={css({
+          minH: 'calc(100vh - 80px)',
+          bg: 'linear-gradient(135deg, #0f0f23 0%, #1a1a3a 50%, #2d1b69 100%)',
+          p: '8',
+        })}
+      >
+        <div className={css({ maxW: '1000px', mx: 'auto' })}>
+          {/* Header */}
+          <div
+            className={css({
+              bg: 'rgba(255, 255, 255, 0.05)',
+              backdropFilter: 'blur(10px)',
+              border: '1px solid rgba(255, 255, 255, 0.1)',
+              rounded: 'lg',
+              p: '8',
+              mb: '6',
+            })}
+          >
+            <div className={css({ mb: '4' })}>
+              <button
+                onClick={() => router.push('/arcade-rooms')}
+                className={css({
+                  display: 'inline-flex',
+                  alignItems: 'center',
+                  gap: '2',
+                  color: '#a0a0ff',
+                  fontSize: 'sm',
+                  cursor: 'pointer',
+                  _hover: { color: '#60a5fa' },
+                  mb: '3',
+                })}
+              >
+                ← Back to Rooms
+              </button>
+            </div>
+            <div
+              className={css({
+                display: 'flex',
+                justifyContent: 'space-between',
+                alignItems: 'center',
+                mb: '4',
+              })}
+            >
+              <div>
+                <h1
+                  className={css({ fontSize: '3xl', fontWeight: 'bold', color: 'white', mb: '2' })}
+                >
+                  {room.name}
+                </h1>
+                <div
+                  className={css({ display: 'flex', gap: '4', color: '#a0a0ff', fontSize: 'sm' })}
+                >
+                  <span>🎮 {room.gameName}</span>
+                  <span>👤 Host: {room.creatorName}</span>
+                  <span
+                    className={css({
+                      px: '3',
+                      py: '1',
+                      bg: 'rgba(255, 255, 255, 0.1)',
+                      color: '#fbbf24',
+                      rounded: 'full',
+                      fontWeight: '600',
+                      fontFamily: 'monospace',
+                    })}
+                  >
+                    Code: {room.code}
+                  </span>
+                </div>
+              </div>
+              <div className={css({ display: 'flex', gap: '3', alignItems: 'center' })}>
+                <div
+                  className={css({
+                    display: 'flex',
+                    alignItems: 'center',
+                    gap: '2',
+                    px: '3',
+                    py: '2',
+                    bg: isConnected ? 'rgba(16, 185, 129, 0.2)' : 'rgba(239, 68, 68, 0.2)',
+                    border: `1px solid ${isConnected ? '#10b981' : '#ef4444'}`,
+                    rounded: 'full',
+                  })}
+                >
+                  <div
+                    className={css({
+                      w: '2',
+                      h: '2',
+                      bg: isConnected ? '#10b981' : '#ef4444',
+                      rounded: 'full',
+                    })}
+                  />
+                  <span
+                    className={css({ color: isConnected ? '#10b981' : '#ef4444', fontSize: 'sm' })}
+                  >
+                    {isConnected ? 'Connected' : 'Disconnected'}
+                  </span>
+                </div>
+              </div>
+            </div>
+          </div>
+
+          {/* Game Players - Union of all active players */}
+          <div
+            className={css({
+              bg: 'rgba(255, 255, 255, 0.05)',
+              backdropFilter: 'blur(10px)',
+              border: '1px solid rgba(255, 255, 255, 0.1)',
+              rounded: 'lg',
+              p: '8',
+              mb: '6',
+            })}
+          >
+            <h2 className={css({ fontSize: '2xl', fontWeight: 'bold', color: 'white', mb: '2' })}>
+              🎯 Game Players ({allPlayers.length})
+            </h2>
+            <p className={css({ color: '#a0a0ff', fontSize: 'sm', mb: '4' })}>
+              These players will participate when the game starts
+            </p>
+            {allPlayers.length > 0 ? (
+              <div className={css({ display: 'flex', gap: '2', flexWrap: 'wrap' })}>
+                {allPlayers.map((player) => (
+                  <div
+                    key={player.id}
+                    className={css({
+                      display: 'flex',
+                      alignItems: 'center',
+                      gap: '2',
+                      px: '3',
+                      py: '2',
+                      bg: 'rgba(59, 130, 246, 0.15)',
+                      border: '2px solid rgba(59, 130, 246, 0.4)',
+                      rounded: 'lg',
+                      color: '#60a5fa',
+                      fontWeight: '600',
+                    })}
+                  >
+                    <span className={css({ fontSize: 'xl' })}>{player.emoji}</span>
+                    <span>{player.name}</span>
+                  </div>
+                ))}
+              </div>
+            ) : (
+              <div
+                className={css({
+                  color: '#6b7280',
+                  fontStyle: 'italic',
+                  textAlign: 'center',
+                  py: '4',
+                })}
+              >
+                No active players yet. Members need to set up their players.
+              </div>
+            )}
+          </div>
+
+          {/* Members List */}
+          <div
+            className={css({
+              bg: 'rgba(255, 255, 255, 0.05)',
+              backdropFilter: 'blur(10px)',
+              border: '1px solid rgba(255, 255, 255, 0.1)',
+              rounded: 'lg',
+              p: '8',
+              mb: '6',
+            })}
+          >
+            <h2 className={css({ fontSize: '2xl', fontWeight: 'bold', color: 'white', mb: '2' })}>
+              👥 Room Members ({onlineMembers.length}/{members.length})
+            </h2>
+            <p className={css({ color: '#a0a0ff', fontSize: 'sm', mb: '4' })}>
+              Users in this room and their active players
+            </p>
+            <div className={css({ display: 'grid', gap: '3' })}>
+              {members.map((member) => {
+                const players = memberPlayers[member.userId] || []
+                return (
+                  <div
+                    key={member.id}
+                    className={css({
+                      display: 'flex',
+                      flexDirection: 'column',
+                      gap: '2',
+                      p: '4',
+                      bg: 'rgba(255, 255, 255, 0.05)',
+                      border: '1px solid rgba(255, 255, 255, 0.1)',
+                      rounded: 'lg',
+                      opacity: member.isOnline ? 1 : 0.5,
+                    })}
+                  >
+                    <div
+                      className={css({
+                        display: 'flex',
+                        justifyContent: 'space-between',
+                        alignItems: 'center',
+                      })}
+                    >
+                      <div className={css({ display: 'flex', alignItems: 'center', gap: '3' })}>
+                        <div
+                          className={css({
+                            w: '3',
+                            h: '3',
+                            bg: member.isOnline ? '#10b981' : '#6b7280',
+                            rounded: 'full',
+                          })}
+                        />
+                        <span className={css({ color: 'white', fontWeight: '600' })}>
+                          {member.displayName}
+                        </span>
+                        {member.isCreator && (
+                          <span
+                            className={css({
+                              px: '2',
+                              py: '1',
+                              bg: 'rgba(251, 191, 36, 0.2)',
+                              color: '#fbbf24',
+                              rounded: 'full',
+                              fontSize: 'xs',
+                              fontWeight: '600',
+                            })}
+                          >
+                            HOST
+                          </span>
+                        )}
+                      </div>
+                      <span className={css({ color: '#a0a0ff', fontSize: 'sm' })}>
+                        {member.isOnline ? '🟢 Online' : '⚫ Offline'}
+                      </span>
+                    </div>
+                    {players.length > 0 && (
+                      <div
+                        className={css({ display: 'flex', gap: '2', flexWrap: 'wrap', ml: '6' })}
+                      >
+                        <span className={css({ color: '#a0a0ff', fontSize: 'xs', mr: '1' })}>
+                          Players:
+                        </span>
+                        {players.map((player) => (
+                          <span
+                            key={player.id}
+                            className={css({
+                              px: '2',
+                              py: '1',
+                              bg: 'rgba(59, 130, 246, 0.2)',
+                              color: '#60a5fa',
+                              border: '1px solid rgba(59, 130, 246, 0.3)',
+                              rounded: 'full',
+                              fontSize: 'xs',
+                              fontWeight: '600',
+                            })}
+                          >
+                            {player.emoji} {player.name}
+                          </span>
+                        ))}
+                      </div>
+                    )}
+                    {players.length === 0 && (
+                      <div
+                        className={css({
+                          ml: '6',
+                          color: '#6b7280',
+                          fontSize: 'xs',
+                          fontStyle: 'italic',
+                        })}
+                      >
+                        No active players
+                      </div>
+                    )}
+                  </div>
+                )
+              })}
+            </div>
+          </div>
+
+          {/* Actions */}
+          <div className={css({ display: 'flex', gap: '4' })}>
+            {isMember ? (
+              <>
+                <button
+                  onClick={leaveRoom}
+                  className={css({
+                    flex: 1,
+                    px: '6',
+                    py: '4',
+                    bg: 'rgba(255, 255, 255, 0.1)',
+                    color: 'white',
+                    rounded: 'lg',
+                    fontWeight: '600',
+                    cursor: 'pointer',
+                    _hover: { bg: 'rgba(255, 255, 255, 0.15)' },
+                  })}
+                >
+                  Leave Room
+                </button>
+                <button
+                  onClick={startGame}
+                  disabled={allPlayers.length < 1}
+                  className={css({
+                    flex: 2,
+                    px: '6',
+                    py: '4',
+                    bg: allPlayers.length < 1 ? '#6b7280' : '#10b981',
+                    color: 'white',
+                    rounded: 'lg',
+                    fontSize: 'xl',
+                    fontWeight: '600',
+                    cursor: allPlayers.length < 1 ? 'not-allowed' : 'pointer',
+                    opacity: allPlayers.length < 1 ? 0.5 : 1,
+                    _hover: allPlayers.length < 1 ? {} : { bg: '#059669' },
+                  })}
+                >
+                  {allPlayers.length < 1
+                    ? 'Waiting for players...'
+                    : `🎮 Start Game (${allPlayers.length} players)`}
+                </button>
+              </>
+            ) : (
+              <>
+                <button
+                  onClick={() => router.push('/arcade-rooms')}
+                  className={css({
+                    flex: 1,
+                    px: '6',
+                    py: '4',
+                    bg: 'rgba(255, 255, 255, 0.1)',
+                    color: 'white',
+                    rounded: 'lg',
+                    fontWeight: '600',
+                    cursor: 'pointer',
+                    _hover: { bg: 'rgba(255, 255, 255, 0.15)' },
+                  })}
+                >
+                  Back to Rooms
+                </button>
+                <button
+                  onClick={joinRoom}
+                  disabled={room.isLocked}
+                  className={css({
+                    flex: 2,
+                    px: '6',
+                    py: '4',
+                    bg: room.isLocked ? '#6b7280' : '#3b82f6',
+                    color: 'white',
+                    rounded: 'lg',
+                    fontSize: 'xl',
+                    fontWeight: '600',
+                    cursor: room.isLocked ? 'not-allowed' : 'pointer',
+                    opacity: room.isLocked ? 0.5 : 1,
+                    _hover: room.isLocked ? {} : { bg: '#2563eb' },
+                  })}
+                >
+                  {room.isLocked ? '🔒 Room Locked' : 'Join Room'}
+                </button>
+              </>
+            )}
+          </div>
+        </div>
+      </div>
+    </PageWithNav>
+  )
+}

apps/web/src/app/arcade-rooms/__tests__/room-navigation.test.tsx

@@ -0,0 +1,311 @@
+import { render, screen, waitFor } from '@testing-library/react'
+import * as nextNavigation from 'next/navigation'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import * as arcadeGuard from '@/hooks/useArcadeGuard'
+import * as roomData from '@/hooks/useRoomData'
+import * as viewerId from '@/hooks/useViewerId'
+
+// Mock Next.js navigation
+vi.mock('next/navigation', () => ({
+  useRouter: vi.fn(),
+  usePathname: vi.fn(),
+  useParams: vi.fn(),
+}))
+
+// Mock hooks
+vi.mock('@/hooks/useArcadeGuard')
+vi.mock('@/hooks/useRoomData')
+vi.mock('@/hooks/useViewerId')
+vi.mock('@/hooks/useUserPlayers', () => ({
+  useUserPlayers: () => ({ data: [], isLoading: false }),
+  useCreatePlayer: () => ({ mutate: vi.fn() }),
+  useUpdatePlayer: () => ({ mutate: vi.fn() }),
+  useDeletePlayer: () => ({ mutate: vi.fn() }),
+}))
+vi.mock('@/hooks/useArcadeSocket', () => ({
+  useArcadeSocket: () => ({
+    connected: false,
+    joinSession: vi.fn(),
+    socket: null,
+    sendMove: vi.fn(),
+    exitSession: vi.fn(),
+    pingSession: vi.fn(),
+  }),
+}))
+
+// Mock styled-system
+vi.mock('../../../../styled-system/css', () => ({
+  css: () => '',
+}))
+
+// Mock components
+vi.mock('@/components/PageWithNav', () => ({
+  PageWithNav: ({ children }: { children: React.ReactNode }) => <div>{children}</div>,
+}))
+
+// Import pages after mocks
+import RoomBrowserPage from '../page'
+
+describe('Room Navigation with Active Sessions', () => {
+  const mockRouter = {
+    push: vi.fn(),
+    replace: vi.fn(),
+    back: vi.fn(),
+  }
+
+  beforeEach(() => {
+    vi.clearAllMocks()
+    vi.spyOn(nextNavigation, 'useRouter').mockReturnValue(mockRouter as any)
+    vi.spyOn(nextNavigation, 'usePathname').mockReturnValue('/arcade-rooms')
+    vi.spyOn(viewerId, 'useViewerId').mockReturnValue({
+      data: 'test-user',
+      isLoading: false,
+      isPending: false,
+      error: null,
+    } as any)
+    global.fetch = vi.fn()
+  })
+
+  describe('RoomBrowserPage', () => {
+    it('should render room browser without redirecting when user has active game session', async () => {
+      // User has an active game session
+      vi.spyOn(arcadeGuard, 'useArcadeGuard').mockReturnValue({
+        hasActiveSession: true,
+        loading: false,
+        activeSession: {
+          gameUrl: '/arcade/room',
+          currentGame: 'matching',
+        },
+      })
+
+      // User is in a room
+      vi.spyOn(roomData, 'useRoomData').mockReturnValue({
+        roomData: {
+          id: 'room-1',
+          name: 'Test Room',
+          code: 'ABC123',
+          gameName: 'matching',
+          members: [],
+          memberPlayers: {},
+        },
+        isLoading: false,
+        isInRoom: true,
+      })
+
+      // Mock rooms API
+      ;(global.fetch as any).mockResolvedValue({
+        ok: true,
+        json: async () => ({
+          rooms: [
+            {
+              id: 'room-1',
+              code: 'ABC123',
+              name: 'Test Room',
+              gameName: 'matching',
+              status: 'lobby',
+              createdAt: new Date(),
+              creatorName: 'Test User',
+              isLocked: false,
+            },
+          ],
+        }),
+      })
+
+      render(<RoomBrowserPage />)
+
+      // Should render the page
+      await waitFor(() => {
+        expect(screen.getByText('🎮 Multiplayer Rooms')).toBeInTheDocument()
+      })
+
+      // Should NOT redirect to /arcade/room
+      expect(mockRouter.push).not.toHaveBeenCalled()
+    })
+
+    it('should NOT redirect when PageWithNav uses arcade guard with enabled=false', async () => {
+      // Simulate PageWithNav calling useArcadeGuard with enabled=false
+      const arcadeGuardSpy = vi.spyOn(arcadeGuard, 'useArcadeGuard')
+
+      // User has an active game session
+      arcadeGuardSpy.mockReturnValue({
+        hasActiveSession: true,
+        loading: false,
+        activeSession: {
+          gameUrl: '/arcade/room',
+          currentGame: 'matching',
+        },
+      })
+
+      vi.spyOn(roomData, 'useRoomData').mockReturnValue({
+        roomData: null,
+        isLoading: false,
+        isInRoom: false,
+      })
+
+      ;(global.fetch as any).mockResolvedValue({
+        ok: true,
+        json: async () => ({ rooms: [] }),
+      })
+
+      render(<RoomBrowserPage />)
+
+      await waitFor(() => {
+        expect(screen.getByText('🎮 Multiplayer Rooms')).toBeInTheDocument()
+      })
+
+      // PageWithNav should have called useArcadeGuard with enabled=false
+      // This is tested in PageWithNav's own tests, but we verify no redirect happened
+      expect(mockRouter.push).not.toHaveBeenCalled()
+    })
+
+    it('should allow navigation to room detail even with active session', async () => {
+      vi.spyOn(arcadeGuard, 'useArcadeGuard').mockReturnValue({
+        hasActiveSession: true,
+        loading: false,
+        activeSession: {
+          gameUrl: '/arcade/room',
+          currentGame: 'matching',
+        },
+      })
+
+      vi.spyOn(roomData, 'useRoomData').mockReturnValue({
+        roomData: null,
+        isLoading: false,
+        isInRoom: false,
+      })
+
+      ;(global.fetch as any).mockResolvedValue({
+        ok: true,
+        json: async () => ({
+          rooms: [
+            {
+              id: 'room-1',
+              code: 'ABC123',
+              name: 'Test Room',
+              gameName: 'matching',
+              status: 'lobby',
+              createdAt: new Date(),
+              creatorName: 'Test User',
+              isLocked: false,
+              isMember: true,
+            },
+          ],
+        }),
+      })
+
+      render(<RoomBrowserPage />)
+
+      await waitFor(() => {
+        expect(screen.getByText('Test Room')).toBeInTheDocument()
+      })
+
+      // Click on the room card
+      const roomCard = screen.getByText('Test Room').parentElement
+      roomCard?.click()
+
+      // Should navigate to room detail, not to /arcade/room
+      await waitFor(() => {
+        expect(mockRouter.push).toHaveBeenCalledWith('/arcade-rooms/room-1')
+      })
+    })
+  })
+
+  describe('Room navigation edge cases', () => {
+    it('should handle rapid navigation between room pages without redirect loops', async () => {
+      vi.spyOn(arcadeGuard, 'useArcadeGuard').mockReturnValue({
+        hasActiveSession: true,
+        loading: false,
+        activeSession: {
+          gameUrl: '/arcade/room',
+          currentGame: 'matching',
+        },
+      })
+
+      vi.spyOn(roomData, 'useRoomData').mockReturnValue({
+        roomData: null,
+        isLoading: false,
+        isInRoom: false,
+      })
+
+      ;(global.fetch as any).mockResolvedValue({
+        ok: true,
+        json: async () => ({ rooms: [] }),
+      })
+
+      const { rerender } = render(<RoomBrowserPage />)
+
+      await waitFor(() => {
+        expect(screen.getByText('🎮 Multiplayer Rooms')).toBeInTheDocument()
+      })
+
+      // Simulate pathname changes (navigating between room pages)
+      vi.spyOn(nextNavigation, 'usePathname').mockReturnValue('/arcade-rooms/room-1')
+      rerender(<RoomBrowserPage />)
+
+      vi.spyOn(nextNavigation, 'usePathname').mockReturnValue('/arcade-rooms')
+      rerender(<RoomBrowserPage />)
+
+      // Should never redirect to game page
+      expect(mockRouter.push).not.toHaveBeenCalledWith('/arcade/room')
+    })
+
+    it('should allow user to leave room and browse other rooms during active game', async () => {
+      // User is in a room with an active game
+      vi.spyOn(arcadeGuard, 'useArcadeGuard').mockReturnValue({
+        hasActiveSession: true,
+        loading: false,
+        activeSession: {
+          gameUrl: '/arcade/room',
+          currentGame: 'matching',
+        },
+      })
+
+      vi.spyOn(roomData, 'useRoomData').mockReturnValue({
+        roomData: {
+          id: 'room-1',
+          name: 'Current Room',
+          code: 'ABC123',
+          gameName: 'matching',
+          members: [],
+          memberPlayers: {},
+        },
+        isLoading: false,
+        isInRoom: true,
+      })
+
+      ;(global.fetch as any).mockResolvedValue({
+        ok: true,
+        json: async () => ({
+          rooms: [
+            {
+              id: 'room-1',
+              name: 'Current Room',
+              code: 'ABC123',
+              gameName: 'matching',
+              status: 'playing',
+              isMember: true,
+            },
+            {
+              id: 'room-2',
+              name: 'Other Room',
+              code: 'DEF456',
+              gameName: 'memory-quiz',
+              status: 'lobby',
+              isMember: false,
+            },
+          ],
+        }),
+      })
+
+      render(<RoomBrowserPage />)
+
+      await waitFor(() => {
+        expect(screen.getByText('Current Room')).toBeInTheDocument()
+        expect(screen.getByText('Other Room')).toBeInTheDocument()
+      })
+
+      // Should be able to view both rooms without redirect
+      expect(mockRouter.push).not.toHaveBeenCalled()
+    })
+  })
+})

apps/web/src/app/arcade-rooms/page.tsx

@@ -0,0 +1,468 @@
+'use client'
+
+import { useEffect, useState } from 'react'
+import { useRouter } from 'next/navigation'
+import { css } from '../../../styled-system/css'
+import { PageWithNav } from '@/components/PageWithNav'
+
+interface Room {
+  id: string
+  code: string
+  name: string
+  gameName: string
+  status: 'lobby' | 'playing' | 'finished'
+  createdAt: Date
+  creatorName: string
+  isLocked: boolean
+  memberCount?: number
+  playerCount?: number
+  isMember?: boolean
+}
+
+export default function RoomBrowserPage() {
+  const router = useRouter()
+  const [rooms, setRooms] = useState<Room[]>([])
+  const [loading, setLoading] = useState(true)
+  const [error, setError] = useState<string | null>(null)
+  const [showCreateModal, setShowCreateModal] = useState(false)
+
+  useEffect(() => {
+    fetchRooms()
+  }, [])
+
+  const fetchRooms = async () => {
+    try {
+      setLoading(true)
+      const response = await fetch('/api/arcade/rooms')
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status}`)
+      }
+      const data = await response.json()
+      setRooms(data.rooms)
+      setError(null)
+    } catch (err) {
+      console.error('Failed to fetch rooms:', err)
+      setError('Failed to load rooms')
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  const createRoom = async (name: string, gameName: string) => {
+    try {
+      const response = await fetch('/api/arcade/rooms', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          name,
+          gameName,
+          creatorName: 'Player',
+          gameConfig: { difficulty: 6 },
+        }),
+      })
+
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status}`)
+      }
+
+      const data = await response.json()
+      router.push(`/arcade-rooms/${data.room.id}`)
+    } catch (err) {
+      console.error('Failed to create room:', err)
+      alert('Failed to create room')
+    }
+  }
+
+  const joinRoom = async (roomId: string) => {
+    try {
+      const response = await fetch(`/api/arcade/rooms/${roomId}/join`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ displayName: 'Player' }),
+      })
+
+      if (!response.ok) {
+        const errorData = await response.json()
+
+        // Handle specific room membership conflict
+        if (errorData.code === 'ROOM_MEMBERSHIP_CONFLICT') {
+          alert(errorData.userMessage || errorData.message)
+          // Refresh the page to update room list state
+          await fetchRooms()
+          return
+        }
+
+        throw new Error(errorData.error || `HTTP ${response.status}`)
+      }
+
+      const data = await response.json()
+
+      // Show notification if user was auto-removed from other rooms
+      if (data.autoLeave) {
+        console.log(`[Room Join] ${data.autoLeave.message}`)
+        // Could show a toast notification here in the future
+      }
+
+      router.push(`/arcade-rooms/${roomId}`)
+    } catch (err) {
+      console.error('Failed to join room:', err)
+      alert('Failed to join room')
+    }
+  }
+
+  return (
+    <PageWithNav>
+      <div
+        className={css({
+          minH: 'calc(100vh - 80px)',
+          bg: 'linear-gradient(135deg, #0f0f23 0%, #1a1a3a 50%, #2d1b69 100%)',
+          p: '8',
+        })}
+      >
+        <div className={css({ maxW: '1200px', mx: 'auto' })}>
+          {/* Header */}
+          <div className={css({ mb: '8', textAlign: 'center' })}>
+            <h1
+              className={css({
+                fontSize: '4xl',
+                fontWeight: 'bold',
+                color: 'white',
+                mb: '4',
+              })}
+            >
+              🎮 Multiplayer Rooms
+            </h1>
+            <p className={css({ color: '#a0a0ff', fontSize: 'lg', mb: '6' })}>
+              Join a room or create your own to play with friends
+            </p>
+            <button
+              onClick={() => setShowCreateModal(true)}
+              className={css({
+                px: '6',
+                py: '3',
+                bg: '#10b981',
+                color: 'white',
+                rounded: 'lg',
+                fontSize: 'lg',
+                fontWeight: '600',
+                cursor: 'pointer',
+                _hover: { bg: '#059669' },
+                transition: 'all 0.2s',
+              })}
+            >
+              + Create New Room
+            </button>
+          </div>
+
+          {/* Room List */}
+          {loading && (
+            <div className={css({ textAlign: 'center', color: 'white', py: '12' })}>
+              Loading rooms...
+            </div>
+          )}
+
+          {error && (
+            <div
+              className={css({
+                bg: '#fef2f2',
+                border: '1px solid #fecaca',
+                color: '#991b1b',
+                p: '4',
+                rounded: 'lg',
+                textAlign: 'center',
+              })}
+            >
+              {error}
+            </div>
+          )}
+
+          {!loading && !error && rooms.length === 0 && (
+            <div
+              className={css({
+                bg: 'rgba(255, 255, 255, 0.05)',
+                backdropFilter: 'blur(10px)',
+                border: '1px solid rgba(255, 255, 255, 0.1)',
+                rounded: 'lg',
+                p: '12',
+                textAlign: 'center',
+                color: 'white',
+              })}
+            >
+              <p className={css({ fontSize: 'xl', mb: '2' })}>No rooms available</p>
+              <p className={css({ color: '#a0a0ff' })}>Be the first to create one!</p>
+            </div>
+          )}
+
+          {!loading && !error && rooms.length > 0 && (
+            <div className={css({ display: 'grid', gap: '4' })}>
+              {rooms.map((room) => (
+                <div
+                  key={room.id}
+                  className={css({
+                    bg: 'rgba(255, 255, 255, 0.05)',
+                    backdropFilter: 'blur(10px)',
+                    border: '1px solid rgba(255, 255, 255, 0.1)',
+                    rounded: 'lg',
+                    p: '6',
+                    transition: 'all 0.2s',
+                    _hover: {
+                      bg: 'rgba(255, 255, 255, 0.08)',
+                      borderColor: 'rgba(255, 255, 255, 0.2)',
+                    },
+                  })}
+                >
+                  <div
+                    className={css({
+                      display: 'flex',
+                      justifyContent: 'space-between',
+                      alignItems: 'center',
+                    })}
+                  >
+                    <div
+                      onClick={() => router.push(`/arcade-rooms/${room.id}`)}
+                      className={css({ flex: 1, cursor: 'pointer' })}
+                    >
+                      <div
+                        className={css({
+                          display: 'flex',
+                          alignItems: 'center',
+                          gap: '3',
+                          mb: '2',
+                        })}
+                      >
+                        <h3
+                          className={css({ fontSize: '2xl', fontWeight: 'bold', color: 'white' })}
+                        >
+                          {room.name}
+                        </h3>
+                        <span
+                          className={css({
+                            px: '3',
+                            py: '1',
+                            bg: 'rgba(255, 255, 255, 0.1)',
+                            color: '#fbbf24',
+                            rounded: 'full',
+                            fontSize: 'sm',
+                            fontWeight: '600',
+                            fontFamily: 'monospace',
+                          })}
+                        >
+                          {room.code}
+                        </span>
+                        {room.isLocked && (
+                          <span className={css({ color: '#f87171', fontSize: 'sm' })}>
+                            🔒 Locked
+                          </span>
+                        )}
+                      </div>
+                      <div
+                        className={css({
+                          display: 'flex',
+                          gap: '4',
+                          color: '#a0a0ff',
+                          fontSize: 'sm',
+                          flexWrap: 'wrap',
+                        })}
+                      >
+                        <span>👤 Host: {room.creatorName}</span>
+                        <span>🎮 {room.gameName}</span>
+                        {room.memberCount !== undefined && (
+                          <span>
+                            👥 {room.memberCount} member{room.memberCount !== 1 ? 's' : ''}
+                          </span>
+                        )}
+                        {room.playerCount !== undefined && room.playerCount > 0 && (
+                          <span>
+                            🎯 {room.playerCount} player{room.playerCount !== 1 ? 's' : ''}
+                          </span>
+                        )}
+                        <span
+                          className={css({
+                            color:
+                              room.status === 'lobby'
+                                ? '#10b981'
+                                : room.status === 'playing'
+                                  ? '#fbbf24'
+                                  : '#6b7280',
+                          })}
+                        >
+                          {room.status === 'lobby'
+                            ? '⏳ Waiting'
+                            : room.status === 'playing'
+                              ? '🎮 Playing'
+                              : '✓ Finished'}
+                        </span>
+                      </div>
+                    </div>
+                    {room.isMember ? (
+                      <div
+                        className={css({
+                          px: '6',
+                          py: '3',
+                          bg: '#10b981',
+                          color: 'white',
+                          rounded: 'lg',
+                          fontWeight: '600',
+                          display: 'flex',
+                          alignItems: 'center',
+                          gap: '2',
+                        })}
+                      >
+                        ✓ Joined
+                      </div>
+                    ) : (
+                      <button
+                        onClick={(e) => {
+                          e.stopPropagation()
+                          joinRoom(room.id)
+                        }}
+                        disabled={room.isLocked}
+                        className={css({
+                          px: '6',
+                          py: '3',
+                          bg: room.isLocked ? '#6b7280' : '#3b82f6',
+                          color: 'white',
+                          rounded: 'lg',
+                          fontWeight: '600',
+                          cursor: room.isLocked ? 'not-allowed' : 'pointer',
+                          opacity: room.isLocked ? 0.5 : 1,
+                          _hover: room.isLocked ? {} : { bg: '#2563eb' },
+                          transition: 'all 0.2s',
+                        })}
+                      >
+                        Join Room
+                      </button>
+                    )}
+                  </div>
+                </div>
+              ))}
+            </div>
+          )}
+        </div>
+
+        {/* Create Room Modal */}
+        {showCreateModal && (
+          <div
+            className={css({
+              position: 'fixed',
+              top: 0,
+              left: 0,
+              right: 0,
+              bottom: 0,
+              bg: 'rgba(0, 0, 0, 0.7)',
+              backdropFilter: 'blur(4px)',
+              display: 'flex',
+              alignItems: 'center',
+              justifyContent: 'center',
+              zIndex: 50,
+            })}
+            onClick={() => setShowCreateModal(false)}
+          >
+            <div
+              className={css({
+                bg: 'white',
+                rounded: 'xl',
+                p: '8',
+                maxW: '500px',
+                w: 'full',
+                mx: '4',
+              })}
+              onClick={(e) => e.stopPropagation()}
+            >
+              <h2 className={css({ fontSize: '2xl', fontWeight: 'bold', mb: '6' })}>
+                Create New Room
+              </h2>
+              <form
+                onSubmit={(e) => {
+                  e.preventDefault()
+                  const formData = new FormData(e.currentTarget)
+                  const name = formData.get('name') as string
+                  const gameName = formData.get('gameName') as string
+                  if (name && gameName) {
+                    createRoom(name, gameName)
+                  }
+                }}
+              >
+                <div className={css({ mb: '4' })}>
+                  <label className={css({ display: 'block', mb: '2', fontWeight: '600' })}>
+                    Room Name
+                  </label>
+                  <input
+                    name="name"
+                    type="text"
+                    required
+                    placeholder="My Awesome Room"
+                    className={css({
+                      w: 'full',
+                      px: '4',
+                      py: '3',
+                      border: '1px solid #d1d5db',
+                      rounded: 'lg',
+                      _focus: { outline: 'none', borderColor: '#3b82f6' },
+                    })}
+                  />
+                </div>
+                <div className={css({ mb: '6' })}>
+                  <label className={css({ display: 'block', mb: '2', fontWeight: '600' })}>
+                    Game
+                  </label>
+                  <select
+                    name="gameName"
+                    required
+                    className={css({
+                      w: 'full',
+                      px: '4',
+                      py: '3',
+                      border: '1px solid #d1d5db',
+                      rounded: 'lg',
+                      _focus: { outline: 'none', borderColor: '#3b82f6' },
+                    })}
+                  >
+                    <option value="matching">Memory Matching</option>
+                    <option value="memory-quiz">Memory Quiz</option>
+                    <option value="complement-race">Complement Race</option>
+                  </select>
+                </div>
+                <div className={css({ display: 'flex', gap: '3' })}>
+                  <button
+                    type="button"
+                    onClick={() => setShowCreateModal(false)}
+                    className={css({
+                      flex: 1,
+                      px: '6',
+                      py: '3',
+                      bg: '#e5e7eb',
+                      color: '#374151',
+                      rounded: 'lg',
+                      fontWeight: '600',
+                      cursor: 'pointer',
+                      _hover: { bg: '#d1d5db' },
+                    })}
+                  >
+                    Cancel
+                  </button>
+                  <button
+                    type="submit"
+                    className={css({
+                      flex: 1,
+                      px: '6',
+                      py: '3',
+                      bg: '#10b981',
+                      color: 'white',
+                      rounded: 'lg',
+                      fontWeight: '600',
+                      cursor: 'pointer',
+                      _hover: { bg: '#059669' },
+                    })}
+                  >
+                    Create Room
+                  </button>
+                </div>
+              </form>
+            </div>
+          </div>
+        )}
+      </div>
+    </PageWithNav>
+  )
+}

apps/web/src/app/arcade/matching/context/ArcadeMemoryPairsContext.tsx

@@ -2,6 +2,7 @@
 
 import { createContext, type ReactNode, useCallback, useContext, useEffect, useMemo } from 'react'
 import { useArcadeSession } from '@/hooks/useArcadeSession'
+import { useRoomData } from '@/hooks/useRoomData'
 import { useViewerId } from '@/hooks/useViewerId'
 import type { GameMove } from '@/lib/arcade/validation'
 import { useGameMode } from '../../../../contexts/GameModeContext'
@@ -104,6 +105,7 @@ const ArcadeMemoryPairsContext = createContext<MemoryPairsContextValue | null>(n
 // Provider component
 export function ArcadeMemoryPairsProvider({ children }: { children: ReactNode }) {
   const { data: viewerId } = useViewerId()
+  const { roomData } = useRoomData()
   const { activePlayerCount, activePlayers: activePlayerIds } = useGameMode()
 
   // Get active player IDs directly as strings (UUIDs)
@@ -112,7 +114,7 @@ export function ArcadeMemoryPairsProvider({ children }: { children: ReactNode })
   // Derive game mode from active player count
   const gameMode = activePlayerCount > 1 ? 'multiplayer' : 'single'
 
-  // Arcade session integration
+  // Arcade session integration with room-wide sync
   const {
     state,
     sendMove,
@@ -120,6 +122,7 @@ export function ArcadeMemoryPairsProvider({ children }: { children: ReactNode })
     exitSession,
   } = useArcadeSession<MemoryPairsState>({
     userId: viewerId || '',
+    roomId: roomData?.id, // Enable multi-user sync for room-based games
     initialState,
     applyMove: applyMoveOptimistically,
   })
@@ -195,7 +198,7 @@ export function ArcadeMemoryPairsProvider({ children }: { children: ReactNode })
         activePlayers,
       },
     })
-  }, [state.gameType, state.difficulty, activePlayers, sendMove])
+  }, [state.gameType, state.difficulty, activePlayers, sendMove, roomData])
 
   const flipCard = useCallback(
     (cardId: string) => {

apps/web/src/app/arcade/room/page.tsx

@@ -0,0 +1,76 @@
+'use client'
+
+import { useRouter } from 'next/navigation'
+import { useEffect } from 'react'
+import { ArcadeGuardedPage } from '@/components/ArcadeGuardedPage'
+import { useRoomData } from '@/hooks/useRoomData'
+import { MemoryPairsGame } from '../matching/components/MemoryPairsGame'
+import { ArcadeMemoryPairsProvider } from '../matching/context/ArcadeMemoryPairsContext'
+
+/**
+ * /arcade/room - Renders the game for the user's current room
+ * Since users can only be in one room at a time, this is a simple singular route
+ */
+export default function RoomPage() {
+  const router = useRouter()
+  const { roomData, isLoading } = useRoomData()
+
+  // Redirect to arcade if no room
+  useEffect(() => {
+    if (!isLoading && !roomData) {
+      router.push('/arcade')
+    }
+  }, [isLoading, roomData, router])
+
+  // Show loading state
+  if (isLoading) {
+    return (
+      <div
+        style={{
+          display: 'flex',
+          alignItems: 'center',
+          justifyContent: 'center',
+          height: '100vh',
+          fontSize: '18px',
+          color: '#666',
+        }}
+      >
+        Loading room...
+      </div>
+    )
+  }
+
+  // Show nothing while redirecting
+  if (!roomData) {
+    return null
+  }
+
+  // Render the appropriate game based on room's gameName
+  switch (roomData.gameName) {
+    case 'matching':
+      return (
+        <ArcadeGuardedPage>
+          <ArcadeMemoryPairsProvider>
+            <MemoryPairsGame />
+          </ArcadeMemoryPairsProvider>
+        </ArcadeGuardedPage>
+      )
+
+    // TODO: Add other games (complement-race, memory-quiz, etc.)
+    default:
+      return (
+        <div
+          style={{
+            display: 'flex',
+            alignItems: 'center',
+            justifyContent: 'center',
+            height: '100vh',
+            fontSize: '18px',
+            color: '#666',
+          }}
+        >
+          Game "{roomData.gameName}" not yet supported
+        </div>
+      )
+  }
+}

apps/web/src/components/PageWithNav.tsx

@@ -2,6 +2,9 @@
 
 import React from 'react'
 import { useGameMode } from '../contexts/GameModeContext'
+import { useArcadeGuard } from '../hooks/useArcadeGuard'
+import { useRoomData } from '../hooks/useRoomData'
+import { useViewerId } from '../hooks/useViewerId'
 import { AppNavBar } from './AppNavBar'
 import { GameContextNav } from './nav/GameContextNav'
 import { PlayerConfigDialog } from './nav/PlayerConfigDialog'
@@ -28,6 +31,9 @@ export function PageWithNav({
   children,
 }: PageWithNavProps) {
   const { players, activePlayers, setActive, activePlayerCount } = useGameMode()
+  const { hasActiveSession, activeSession } = useArcadeGuard({ enabled: false }) // Don't redirect, just get info
+  const { roomData, isInRoom } = useRoomData()
+  const { data: viewerId } = useViewerId()
   const [mounted, setMounted] = React.useState(false)
   const [configurePlayerId, setConfigurePlayerId] = React.useState<string | null>(null)
 
@@ -76,6 +82,36 @@ export function PageWithNav({
   const shouldEmphasize = emphasizeGameContext && mounted
   const showFullscreenSelection = shouldEmphasize && activePlayerCount === 0
 
+  // Compute arcade session info for display
+  const roomInfo =
+    isInRoom && roomData
+      ? {
+          roomName: roomData.name,
+          gameName: roomData.gameName,
+          playerCount: roomData.members.length,
+        }
+      : hasActiveSession && activeSession
+        ? {
+            gameName: activeSession.currentGame,
+            playerCount: activePlayerCount,
+          }
+        : undefined
+
+  // Compute network players (other players in the room, excluding current user)
+  const networkPlayers: Array<{ id: string; emoji?: string; name?: string }> =
+    isInRoom && roomData
+      ? roomData.members
+          .filter((member) => member.userId !== viewerId)
+          .flatMap((member) => {
+            const memberPlayerList = roomData.memberPlayers[member.userId] || []
+            return memberPlayerList.map((player) => ({
+              id: player.id,
+              emoji: player.emoji,
+              name: `${player.name} (${member.displayName})`,
+            }))
+          })
+      : []
+
   // Create nav content if title is provided
   const navContent = navTitle ? (
     <GameContextNav
@@ -93,6 +129,8 @@ export function PageWithNav({
       onSetup={onSetup}
       onNewGame={onNewGame}
       canModifyPlayers={canModifyPlayers}
+      roomInfo={roomInfo}
+      networkPlayers={networkPlayers}
     />
   ) : null
 

apps/web/src/components/nav/GameContextNav.tsx

@@ -4,6 +4,8 @@ import { AddPlayerButton } from './AddPlayerButton'
 import { FullscreenPlayerSelection } from './FullscreenPlayerSelection'
 import { GameControlButtons } from './GameControlButtons'
 import { GameModeIndicator } from './GameModeIndicator'
+import { NetworkPlayerIndicator } from './NetworkPlayerIndicator'
+import { RoomInfo } from './RoomInfo'
 
 type GameMode = 'none' | 'single' | 'battle' | 'tournament'
 
@@ -13,6 +15,18 @@ interface Player {
   emoji: string
 }
 
+interface NetworkPlayer {
+  id: string
+  emoji?: string
+  name?: string
+}
+
+interface ArcadeRoomInfo {
+  roomName?: string
+  gameName: string
+  playerCount: number
+}
+
 interface GameContextNavProps {
   navTitle: string
   navEmoji?: string
@@ -28,6 +42,9 @@ interface GameContextNavProps {
   onSetup?: () => void
   onNewGame?: () => void
   canModifyPlayers?: boolean
+  // Arcade session info
+  networkPlayers?: NetworkPlayer[]
+  roomInfo?: ArcadeRoomInfo
 }
 
 export function GameContextNav({
@@ -45,6 +62,8 @@ export function GameContextNav({
   onSetup,
   onNewGame,
   canModifyPlayers = true,
+  networkPlayers = [],
+  roomInfo,
 }: GameContextNavProps) {
   const [_isTransitioning, setIsTransitioning] = React.useState(false)
   const [layoutMode, setLayoutMode] = React.useState<'column' | 'row'>(
@@ -113,6 +132,35 @@ export function GameContextNav({
           showFullscreenSelection={showFullscreenSelection}
         />
 
+        {/* Room Info - show when in arcade session */}
+        {roomInfo && !showFullscreenSelection && (
+          <RoomInfo
+            roomName={roomInfo.roomName}
+            gameName={roomInfo.gameName}
+            playerCount={roomInfo.playerCount}
+            shouldEmphasize={shouldEmphasize}
+          />
+        )}
+
+        {/* Network Players - show other players in the room */}
+        {networkPlayers.length > 0 && !showFullscreenSelection && (
+          <div
+            style={{
+              display: 'flex',
+              alignItems: 'center',
+              gap: shouldEmphasize ? '12px' : '6px',
+            }}
+          >
+            {networkPlayers.map((player) => (
+              <NetworkPlayerIndicator
+                key={player.id}
+                player={player}
+                shouldEmphasize={shouldEmphasize}
+              />
+            ))}
+          </div>
+        )}
+
         {/* Game Control Buttons - only show during active game */}
         {!showFullscreenSelection && !canModifyPlayers && (
           <GameControlButtons onSetup={onSetup} onNewGame={onNewGame} onQuit={onExitSession} />

apps/web/src/components/nav/NetworkPlayerIndicator.tsx

@@ -0,0 +1,121 @@
+import React from 'react'
+
+interface NetworkPlayer {
+  id: string
+  emoji?: string
+  name?: string
+}
+
+interface NetworkPlayerIndicatorProps {
+  player: NetworkPlayer
+  shouldEmphasize: boolean
+}
+
+/**
+ * Displays a network player with a special "network" frame border
+ * to distinguish them from local players
+ */
+export function NetworkPlayerIndicator({ player, shouldEmphasize }: NetworkPlayerIndicatorProps) {
+  const [isHovered, setIsHovered] = React.useState(false)
+
+  return (
+    <div
+      style={{
+        position: 'relative',
+        fontSize: shouldEmphasize ? '48px' : '20px',
+        lineHeight: 1,
+        transition: 'all 0.4s cubic-bezier(0.4, 0, 0.2, 1)',
+        cursor: 'default',
+      }}
+      title={player.name || `Network Player ${player.id.slice(0, 8)}`}
+      onMouseEnter={() => setIsHovered(true)}
+      onMouseLeave={() => setIsHovered(false)}
+    >
+      {/* Network frame border */}
+      <div
+        style={{
+          position: 'absolute',
+          inset: '-6px',
+          borderRadius: '8px',
+          background: `
+            linear-gradient(135deg,
+              rgba(59, 130, 246, 0.4),
+              rgba(147, 51, 234, 0.4),
+              rgba(236, 72, 153, 0.4))
+          `,
+          opacity: isHovered ? 1 : 0.7,
+          transition: 'opacity 0.2s ease',
+          zIndex: -1,
+        }}
+      />
+
+      {/* Animated network signal indicator */}
+      <div
+        style={{
+          position: 'absolute',
+          top: '-8px',
+          right: '-8px',
+          width: '12px',
+          height: '12px',
+          borderRadius: '50%',
+          background: 'rgba(34, 197, 94, 0.9)',
+          boxShadow: '0 0 8px rgba(34, 197, 94, 0.6)',
+          animation: 'networkPulse 2s ease-in-out infinite',
+          zIndex: 1,
+        }}
+        title="Connected"
+      />
+
+      {/* Player emoji or fallback */}
+      <div
+        style={{
+          position: 'relative',
+          filter: shouldEmphasize ? 'drop-shadow(0 4px 8px rgba(0,0,0,0.25))' : 'none',
+        }}
+      >
+        {player.emoji || '🌐'}
+      </div>
+
+      {/* Network icon badge */}
+      <div
+        style={{
+          position: 'absolute',
+          bottom: '-4px',
+          left: '-4px',
+          width: '16px',
+          height: '16px',
+          borderRadius: '50%',
+          border: '2px solid white',
+          background: 'linear-gradient(135deg, #3b82f6, #8b5cf6)',
+          color: 'white',
+          fontSize: '8px',
+          display: 'flex',
+          alignItems: 'center',
+          justifyContent: 'center',
+          boxShadow: '0 2px 6px rgba(0,0,0,0.3)',
+          zIndex: 1,
+        }}
+        title="Network Player"
+      >
+        📡
+      </div>
+
+      <style
+        dangerouslySetInnerHTML={{
+          __html: `
+            @keyframes networkPulse {
+              0%, 100% {
+                opacity: 1;
+                transform: scale(1);
+              }
+              50% {
+                opacity: 0.5;
+                transform: scale(1.2);
+              }
+            }
+          `,
+        }}
+      />
+    </div>
+  )
+}

apps/web/src/components/nav/RoomInfo.tsx

@@ -0,0 +1,88 @@
+interface RoomInfoProps {
+  roomName?: string
+  gameName: string
+  playerCount: number
+  shouldEmphasize: boolean
+}
+
+/**
+ * Displays current arcade room/session information
+ */
+export function RoomInfo({ roomName, gameName, playerCount, shouldEmphasize }: RoomInfoProps) {
+  return (
+    <div
+      style={{
+        display: 'flex',
+        alignItems: 'center',
+        gap: '8px',
+        padding: shouldEmphasize ? '8px 16px' : '4px 12px',
+        background: 'linear-gradient(135deg, rgba(59, 130, 246, 0.2), rgba(147, 51, 234, 0.2))',
+        borderRadius: '12px',
+        border: '2px solid rgba(59, 130, 246, 0.4)',
+        fontSize: shouldEmphasize ? '16px' : '14px',
+        fontWeight: '600',
+        color: 'rgba(255, 255, 255, 0.95)',
+        transition: 'all 0.4s cubic-bezier(0.4, 0, 0.2, 1)',
+        boxShadow: '0 4px 12px rgba(59, 130, 246, 0.2)',
+      }}
+      title="Active Arcade Session"
+    >
+      {/* Room icon */}
+      <div
+        style={{
+          fontSize: shouldEmphasize ? '20px' : '16px',
+          display: 'flex',
+          alignItems: 'center',
+        }}
+      >
+        🎮
+      </div>
+
+      {/* Room details */}
+      <div
+        style={{
+          display: 'flex',
+          flexDirection: 'column',
+          gap: '2px',
+        }}
+      >
+        <div
+          style={{
+            fontSize: shouldEmphasize ? '14px' : '12px',
+            opacity: 0.8,
+            textTransform: 'uppercase',
+            letterSpacing: '0.5px',
+          }}
+        >
+          {roomName ? 'Room' : 'Arcade Session'}
+        </div>
+        <div
+          style={{
+            fontSize: shouldEmphasize ? '16px' : '14px',
+            fontWeight: 'bold',
+          }}
+        >
+          {roomName || gameName}
+        </div>
+      </div>
+
+      {/* Player count badge */}
+      <div
+        style={{
+          marginLeft: '8px',
+          padding: '4px 8px',
+          background: 'rgba(255, 255, 255, 0.2)',
+          borderRadius: '8px',
+          fontSize: shouldEmphasize ? '14px' : '12px',
+          fontWeight: 'bold',
+          display: 'flex',
+          alignItems: 'center',
+          gap: '4px',
+        }}
+      >
+        <span>👥</span>
+        <span>{playerCount}</span>
+      </div>
+    </div>
+  )
+}

apps/web/src/contexts/GameModeContext.tsx

@@ -8,6 +8,8 @@ import {
   useUpdatePlayer,
   useUserPlayers,
 } from '@/hooks/useUserPlayers'
+import { useRoomData } from '@/hooks/useRoomData'
+import { useViewerId } from '@/hooks/useViewerId'
 import { getNextPlayerColor } from '../types/player'
 
 // Client-side Player type (compatible with old type)
@@ -66,28 +68,72 @@ export function GameModeProvider({ children }: { children: ReactNode }) {
   const { mutate: createPlayer } = useCreatePlayer()
   const { mutate: updatePlayerMutation } = useUpdatePlayer()
   const { mutate: deletePlayer } = useDeletePlayer()
+  const { roomData } = useRoomData()
+  const { data: viewerId } = useViewerId()
 
   const [isInitialized, setIsInitialized] = useState(false)
 
-  // Convert DB players to Map
-  const players = useMemo(() => {
+  // Convert DB players to Map (local players)
+  const localPlayers = useMemo(() => {
     const map = new Map<string, Player>()
     dbPlayers.forEach((dbPlayer) => {
-      map.set(dbPlayer.id, toClientPlayer(dbPlayer))
+      map.set(dbPlayer.id, {
+        ...toClientPlayer(dbPlayer),
+        isLocal: true,
+      })
     })
     return map
   }, [dbPlayers])
 
-  // Track active players from DB isActive status
+  // When in a room, merge all players from all room members
+  const players = useMemo(() => {
+    const map = new Map<string, Player>(localPlayers)
+
+    if (roomData) {
+      // Add players from other room members (marked as remote)
+      Object.entries(roomData.memberPlayers).forEach(([userId, memberPlayers]) => {
+        // Skip the current user's players (already in localPlayers)
+        if (userId === viewerId) return
+
+        memberPlayers.forEach((roomPlayer) => {
+          map.set(roomPlayer.id, {
+            id: roomPlayer.id,
+            name: roomPlayer.name,
+            emoji: roomPlayer.emoji,
+            color: roomPlayer.color,
+            createdAt: Date.now(),
+            isActive: true, // Players in memberPlayers are active
+            isLocal: false, // Remote player
+          })
+        })
+      })
+    }
+
+    return map
+  }, [localPlayers, roomData, viewerId])
+
+  // Track active players (local + room members when in a room)
   const activePlayers = useMemo(() => {
     const set = new Set<string>()
-    dbPlayers.forEach((player) => {
-      if (player.isActive) {
-        set.add(player.id)
-      }
-    })
+
+    if (roomData) {
+      // In room mode: all players from all members are active
+      Object.values(roomData.memberPlayers).forEach((memberPlayers) => {
+        memberPlayers.forEach((player) => {
+          set.add(player.id)
+        })
+      })
+    } else {
+      // Solo mode: only local active players
+      dbPlayers.forEach((player) => {
+        if (player.isActive) {
+          set.add(player.id)
+        }
+      })
+    }
+
     return set
-  }, [dbPlayers])
+  }, [dbPlayers, roomData])
 
   // Initialize with default players if none exist
   useEffect(() => {
@@ -125,15 +171,33 @@ export function GameModeProvider({ children }: { children: ReactNode }) {
   }
 
   const updatePlayer = (id: string, updates: Partial<Player>) => {
-    updatePlayerMutation({ id, updates })
+    const player = players.get(id)
+    // Only allow updating local players
+    if (player?.isLocal) {
+      updatePlayerMutation({ id, updates })
+    } else {
+      console.warn('[GameModeContext] Cannot update remote player:', id)
+    }
   }
 
   const removePlayer = (id: string) => {
-    deletePlayer(id)
+    const player = players.get(id)
+    // Only allow removing local players
+    if (player?.isLocal) {
+      deletePlayer(id)
+    } else {
+      console.warn('[GameModeContext] Cannot remove remote player:', id)
+    }
   }
 
   const setActive = (id: string, active: boolean) => {
-    updatePlayerMutation({ id, updates: { isActive: active } })
+    const player = players.get(id)
+    // Only allow changing active status of local players
+    if (player?.isLocal) {
+      updatePlayerMutation({ id, updates: { isActive: active } })
+    } else {
+      console.warn('[GameModeContext] Cannot change active status of remote player:', id)
+    }
   }
 
   const getActivePlayers = (): Player[] => {

apps/web/src/db/schema/room-members.ts

@@ -1,29 +1,36 @@
 import { createId } from '@paralleldrive/cuid2'
-import { integer, sqliteTable, text } from 'drizzle-orm/sqlite-core'
+import { integer, sqliteTable, text, uniqueIndex } from 'drizzle-orm/sqlite-core'
 import { arcadeRooms } from './arcade-rooms'
 
-export const roomMembers = sqliteTable('room_members', {
-  id: text('id')
-    .primaryKey()
-    .$defaultFn(() => createId()),
+export const roomMembers = sqliteTable(
+  'room_members',
+  {
+    id: text('id')
+      .primaryKey()
+      .$defaultFn(() => createId()),
 
-  roomId: text('room_id')
-    .notNull()
-    .references(() => arcadeRooms.id, { onDelete: 'cascade' }),
+    roomId: text('room_id')
+      .notNull()
+      .references(() => arcadeRooms.id, { onDelete: 'cascade' }),
 
-  userId: text('user_id').notNull(), // User/guest ID
-  displayName: text('display_name', { length: 50 }).notNull(),
+    userId: text('user_id').notNull(), // User/guest ID - UNIQUE: one room per user (enforced by index below)
+    displayName: text('display_name', { length: 50 }).notNull(),
 
-  isCreator: integer('is_creator', { mode: 'boolean' }).notNull().default(false),
+    isCreator: integer('is_creator', { mode: 'boolean' }).notNull().default(false),
 
-  joinedAt: integer('joined_at', { mode: 'timestamp' })
-    .notNull()
-    .$defaultFn(() => new Date()),
-  lastSeen: integer('last_seen', { mode: 'timestamp' })
-    .notNull()
-    .$defaultFn(() => new Date()),
-  isOnline: integer('is_online', { mode: 'boolean' }).notNull().default(true),
-})
+    joinedAt: integer('joined_at', { mode: 'timestamp' })
+      .notNull()
+      .$defaultFn(() => new Date()),
+    lastSeen: integer('last_seen', { mode: 'timestamp' })
+      .notNull()
+      .$defaultFn(() => new Date()),
+    isOnline: integer('is_online', { mode: 'boolean' }).notNull().default(true),
+  },
+  (table) => ({
+    // Explicit unique index for clarity and database-level enforcement
+    userIdIdx: uniqueIndex('idx_room_members_user_id_unique').on(table.userId),
+  })
+)
 
 export type RoomMember = typeof roomMembers.$inferSelect
 export type NewRoomMember = typeof roomMembers.$inferInsert

apps/web/src/hooks/__tests__/useArcadeGuard.test.ts

@@ -65,9 +65,11 @@ describe('useArcadeGuard', () => {
 
   it('should fetch active session on mount', async () => {
     const mockSession = {
-      gameUrl: '/arcade/matching',
-      currentGame: 'matching',
-      gameState: {},
+      session: {
+        gameUrl: '/arcade/matching',
+        currentGame: 'matching',
+        gameState: {},
+      },
     }
 
     ;(global.fetch as any).mockResolvedValue({
@@ -91,9 +93,11 @@ describe('useArcadeGuard', () => {
 
   it('should redirect to active session if on different page', async () => {
     const mockSession = {
-      gameUrl: '/arcade/memory-quiz',
-      currentGame: 'memory-quiz',
-      gameState: {},
+      session: {
+        gameUrl: '/arcade/memory-quiz',
+        currentGame: 'memory-quiz',
+        gameState: {},
+      },
     }
 
     ;(global.fetch as any).mockResolvedValue({
@@ -112,9 +116,11 @@ describe('useArcadeGuard', () => {
 
   it('should NOT redirect if already on active session page', async () => {
     const mockSession = {
-      gameUrl: '/arcade/matching',
-      currentGame: 'matching',
-      gameState: {},
+      session: {
+        gameUrl: '/arcade/matching',
+        currentGame: 'matching',
+        gameState: {},
+      },
     }
 
     ;(global.fetch as any).mockResolvedValue({
@@ -152,9 +158,11 @@ describe('useArcadeGuard', () => {
   it('should call onRedirect callback when redirecting', async () => {
     const onRedirect = vi.fn()
     const mockSession = {
-      gameUrl: '/arcade/memory-quiz',
-      currentGame: 'memory-quiz',
-      gameState: {},
+      session: {
+        gameUrl: '/arcade/memory-quiz',
+        currentGame: 'memory-quiz',
+        gameState: {},
+      },
     }
 
     ;(global.fetch as any).mockResolvedValue({
@@ -248,9 +256,11 @@ describe('useArcadeGuard', () => {
     })
 
     const mockSession = {
-      gameUrl: '/arcade/matching',
-      currentGame: 'matching',
-      gameState: {},
+      session: {
+        gameUrl: '/arcade/matching',
+        currentGame: 'matching',
+        gameState: {},
+      },
     }
 
     ;(global.fetch as any).mockResolvedValue({
@@ -285,4 +295,136 @@ describe('useArcadeGuard', () => {
     // Should not crash, just set loading to false
     expect(result.current.hasActiveSession).toBe(false)
   })
+
+  describe('enabled flag behavior', () => {
+    it('should NOT redirect from HTTP check when enabled=false', async () => {
+      const mockSession = {
+        session: {
+          gameUrl: '/arcade/memory-quiz',
+          currentGame: 'memory-quiz',
+          gameState: {},
+        },
+      }
+
+      ;(global.fetch as any).mockResolvedValue({
+        ok: true,
+        json: async () => mockSession,
+      })
+
+      vi.spyOn(nextNavigation, 'usePathname').mockReturnValue('/arcade-rooms')
+
+      renderHook(() => useArcadeGuard({ enabled: false }))
+
+      await waitFor(() => {
+        expect(global.fetch).not.toHaveBeenCalled()
+      })
+
+      // Should NOT redirect
+      expect(mockRouter.push).not.toHaveBeenCalled()
+    })
+
+    it('should NOT redirect from WebSocket when enabled=false', async () => {
+      let onSessionStateCallback: ((data: any) => void) | null = null
+
+      vi.spyOn(arcadeSocket, 'useArcadeSocket').mockImplementation((events) => {
+        onSessionStateCallback = events?.onSessionState || null
+        return mockUseArcadeSocket
+      })
+
+      ;(global.fetch as any).mockResolvedValue({
+        ok: false,
+        status: 404,
+      })
+
+      vi.spyOn(nextNavigation, 'usePathname').mockReturnValue('/arcade-rooms')
+
+      const { result } = renderHook(() => useArcadeGuard({ enabled: false }))
+
+      await waitFor(() => {
+        expect(result.current.loading).toBe(false)
+      })
+
+      // Simulate session-state event from WebSocket
+      onSessionStateCallback?.({
+        gameUrl: '/arcade/room',
+        currentGame: 'matching',
+        gameState: {},
+        activePlayers: [1],
+        version: 1,
+      })
+
+      await waitFor(() => {
+        // Should track the session
+        expect(result.current.hasActiveSession).toBe(true)
+        expect(result.current.activeSession).toEqual({
+          gameUrl: '/arcade/room',
+          currentGame: 'matching',
+        })
+      })
+
+      // But should NOT redirect since enabled=false
+      expect(mockRouter.push).not.toHaveBeenCalled()
+    })
+
+    it('should STILL redirect from WebSocket when enabled=true', async () => {
+      let onSessionStateCallback: ((data: any) => void) | null = null
+
+      vi.spyOn(arcadeSocket, 'useArcadeSocket').mockImplementation((events) => {
+        onSessionStateCallback = events?.onSessionState || null
+        return mockUseArcadeSocket
+      })
+
+      ;(global.fetch as any).mockResolvedValue({
+        ok: false,
+        status: 404,
+      })
+
+      vi.spyOn(nextNavigation, 'usePathname').mockReturnValue('/arcade-rooms')
+
+      renderHook(() => useArcadeGuard({ enabled: true }))
+
+      await waitFor(() => {
+        expect(mockUseArcadeSocket.joinSession).toHaveBeenCalled()
+      })
+
+      // Simulate session-state event from WebSocket
+      onSessionStateCallback?.({
+        gameUrl: '/arcade/room',
+        currentGame: 'matching',
+        gameState: {},
+        activePlayers: [1],
+        version: 1,
+      })
+
+      // Should redirect when enabled=true
+      await waitFor(() => {
+        expect(mockRouter.push).toHaveBeenCalledWith('/arcade/room')
+      })
+    })
+
+    it('should track session state even when enabled=false', async () => {
+      const mockSession = {
+        session: {
+          gameUrl: '/arcade/room',
+          currentGame: 'matching',
+          gameState: {},
+        },
+      }
+
+      ;(global.fetch as any).mockResolvedValue({
+        ok: true,
+        json: async () => mockSession,
+      })
+
+      const { result } = renderHook(() => useArcadeGuard({ enabled: false }))
+
+      await waitFor(() => {
+        expect(result.current.loading).toBe(false)
+      })
+
+      // Should still provide session info even without redirects
+      expect(result.current.hasActiveSession).toBe(false) // No fetch happened
+      expect(result.current.activeSession).toBe(null)
+    })
+  })
 })

apps/web/src/hooks/useArcadeGuard.ts

@@ -73,8 +73,8 @@ export function useArcadeGuard(options: UseArcadeGuardOptions = {}): UseArcadeGu
         currentGame: data.currentGame,
       })
 
-      // Redirect if we're not already on the active game page
-      if (pathname !== data.gameUrl) {
+      // Redirect if we're not already on the active game page (only if enabled)
+      if (enabled && pathname !== data.gameUrl) {
         console.log('[ArcadeGuard] Redirecting to active session:', data.gameUrl)
         onRedirect?.(data.gameUrl)
         router.push(data.gameUrl)
@@ -126,8 +126,8 @@ export function useArcadeGuard(options: UseArcadeGuardOptions = {}): UseArcadeGu
             currentGame: session.currentGame,
           })
 
-          // Redirect if we're not already on the active game page
-          if (pathname !== session.gameUrl) {
+          // Redirect if we're not already on the active game page (only if enabled)
+          if (enabled && pathname !== session.gameUrl) {
             console.log('[ArcadeGuard] Redirecting to active session:', session.gameUrl)
             onRedirect?.(session.gameUrl)
             router.push(session.gameUrl)

apps/web/src/hooks/useArcadeSession.ts

@@ -12,6 +12,12 @@ export interface UseArcadeSessionOptions<TState> extends UseOptimisticGameStateO
    */
   userId: string
 
+  /**
+   * Room ID for multi-user sync (optional)
+   * If provided, game state will sync across all users in the room
+   */
+  roomId?: string
+
   /**
    * Auto-join session on mount
    * @default true
@@ -76,7 +82,7 @@ export interface UseArcadeSessionReturn<TState> {
 export function useArcadeSession<TState>(
   options: UseArcadeSessionOptions<TState>
 ): UseArcadeSessionReturn<TState> {
-  const { userId, autoJoin = true, ...optimisticOptions } = options
+  const { userId, roomId, autoJoin = true, ...optimisticOptions } = options
 
   // Optimistic state management
   const optimistic = useOptimisticGameState<TState>(optimisticOptions)
@@ -122,9 +128,9 @@ export function useArcadeSession<TState>(
   // Auto-join session when connected
   useEffect(() => {
     if (connected && autoJoin && userId) {
-      joinSession(userId)
+      joinSession(userId, roomId)
     }
-  }, [connected, autoJoin, userId, joinSession])
+  }, [connected, autoJoin, userId, roomId, joinSession])
 
   // Send move with optimistic update
   const sendMove = useCallback(
@@ -156,9 +162,9 @@ export function useArcadeSession<TState>(
 
   const refresh = useCallback(() => {
     if (connected && userId) {
-      joinSession(userId)
+      joinSession(userId, roomId)
     }
-  }, [connected, userId, joinSession])
+  }, [connected, userId, roomId, joinSession])
 
   return {
     state: optimistic.state,

apps/web/src/hooks/useArcadeSocket.ts

@@ -20,7 +20,7 @@ export interface ArcadeSocketEvents {
 export interface UseArcadeSocketReturn {
   socket: Socket | null
   connected: boolean
-  joinSession: (userId: string) => void
+  joinSession: (userId: string, roomId?: string) => void
   sendMove: (userId: string, move: GameMove) => void
   exitSession: (userId: string) => void
   pingSession: (userId: string) => void
@@ -103,13 +103,17 @@ export function useArcadeSocket(events: ArcadeSocketEvents = {}): UseArcadeSocke
   }, [])
 
   const joinSession = useCallback(
-    (userId: string) => {
+    (userId: string, roomId?: string) => {
       if (!socket) {
         console.warn('[ArcadeSocket] Cannot join session - socket not connected')
         return
       }
-      console.log('[ArcadeSocket] Joining session for user:', userId)
-      socket.emit('join-arcade-session', { userId })
+      console.log(
+        '[ArcadeSocket] Joining session for user:',
+        userId,
+        roomId ? `in room ${roomId}` : '(solo)'
+      )
+      socket.emit('join-arcade-session', { userId, roomId })
     },
     [socket]
   )

apps/web/src/hooks/useRoomData.ts

@@ -0,0 +1,205 @@
+import { useEffect, useState } from 'react'
+import { io, type Socket } from 'socket.io-client'
+import { useViewerId } from './useViewerId'
+
+export interface RoomMember {
+  id: string
+  userId: string
+  displayName: string
+  isOnline: boolean
+  isCreator: boolean
+}
+
+export interface RoomPlayer {
+  id: string
+  name: string
+  emoji: string
+  color: string
+}
+
+export interface RoomData {
+  id: string
+  name: string
+  code: string
+  gameName: string
+  members: RoomMember[]
+  memberPlayers: Record<string, RoomPlayer[]> // userId -> players
+}
+
+/**
+ * Hook to fetch and subscribe to the user's current room data
+ * Returns null if user is not in any room
+ */
+export function useRoomData() {
+  const { data: userId, isPending: isUserIdPending } = useViewerId()
+  const [socket, setSocket] = useState<Socket | null>(null)
+  const [roomData, setRoomData] = useState<RoomData | null>(null)
+  const [isLoading, setIsLoading] = useState(false)
+  const [hasAttemptedFetch, setHasAttemptedFetch] = useState(false)
+
+  // Fetch the user's current room
+  useEffect(() => {
+    if (!userId) {
+      setRoomData(null)
+      setHasAttemptedFetch(false)
+      return
+    }
+
+    setIsLoading(true)
+    setHasAttemptedFetch(false)
+
+    // Fetch current room data
+    fetch('/api/arcade/rooms/current')
+      .then((res) => {
+        if (!res.ok) throw new Error('Failed to fetch current room')
+        return res.json()
+      })
+      .then((data) => {
+        if (data.room) {
+          const roomData = {
+            id: data.room.id,
+            name: data.room.name,
+            code: data.room.code,
+            gameName: data.room.gameName,
+            members: data.members || [],
+            memberPlayers: data.memberPlayers || {},
+          }
+          setRoomData(roomData)
+        } else {
+          setRoomData(null)
+        }
+        setIsLoading(false)
+        setHasAttemptedFetch(true)
+      })
+      .catch((error) => {
+        console.error('[useRoomData] Failed to fetch room data:', error)
+        setRoomData(null)
+        setIsLoading(false)
+        setHasAttemptedFetch(true)
+      })
+  }, [userId])
+
+  // Initialize socket connection when user has a room
+  useEffect(() => {
+    if (!roomData?.id || !userId) {
+      if (socket) {
+        socket.disconnect()
+        setSocket(null)
+      }
+      return
+    }
+
+    const sock = io({ path: '/api/socket' })
+
+    sock.on('connect', () => {
+      // Join the room to receive updates
+      sock.emit('join-room', { roomId: roomData.id, userId })
+    })
+
+    sock.on('disconnect', () => {
+      // Socket disconnected
+    })
+
+    setSocket(sock)
+
+    return () => {
+      if (sock.connected) {
+        // Leave the room before disconnecting
+        sock.emit('leave-room', { roomId: roomData.id, userId })
+        sock.disconnect()
+      }
+    }
+  }, [roomData?.id, userId])
+
+  // Subscribe to real-time updates via socket
+  useEffect(() => {
+    if (!socket || !roomData?.id) return
+
+    const handleRoomJoined = (data: {
+      roomId: string
+      members: RoomMember[]
+      memberPlayers: Record<string, RoomPlayer[]>
+    }) => {
+      if (data.roomId === roomData.id) {
+        setRoomData((prev) => {
+          if (!prev) return null
+          return {
+            ...prev,
+            members: data.members,
+            memberPlayers: data.memberPlayers,
+          }
+        })
+      }
+    }
+
+    const handleMemberJoined = (data: {
+      roomId: string
+      userId: string
+      members: RoomMember[]
+      memberPlayers: Record<string, RoomPlayer[]>
+    }) => {
+      if (data.roomId === roomData.id) {
+        setRoomData((prev) => {
+          if (!prev) return null
+          return {
+            ...prev,
+            members: data.members,
+            memberPlayers: data.memberPlayers,
+          }
+        })
+      }
+    }
+
+    const handleMemberLeft = (data: {
+      roomId: string
+      userId: string
+      members: RoomMember[]
+      memberPlayers: Record<string, RoomPlayer[]>
+    }) => {
+      if (data.roomId === roomData.id) {
+        setRoomData((prev) => {
+          if (!prev) return null
+          return {
+            ...prev,
+            members: data.members,
+            memberPlayers: data.memberPlayers,
+          }
+        })
+      }
+    }
+
+    const handleRoomPlayersUpdated = (data: {
+      roomId: string
+      memberPlayers: Record<string, RoomPlayer[]>
+    }) => {
+      if (data.roomId === roomData.id) {
+        setRoomData((prev) => {
+          if (!prev) return null
+          return {
+            ...prev,
+            memberPlayers: data.memberPlayers,
+          }
+        })
+      }
+    }
+
+    socket.on('room-joined', handleRoomJoined)
+    socket.on('member-joined', handleMemberJoined)
+    socket.on('member-left', handleMemberLeft)
+    socket.on('room-players-updated', handleRoomPlayersUpdated)
+
+    return () => {
+      socket.off('room-joined', handleRoomJoined)
+      socket.off('member-joined', handleMemberJoined)
+      socket.off('member-left', handleMemberLeft)
+      socket.off('room-players-updated', handleRoomPlayersUpdated)
+    }
+  }, [socket, roomData?.id])
+
+  return {
+    roomData,
+    // Loading if: userId is pending, currently fetching, or have userId but haven't tried fetching yet
+    isLoading: isUserIdPending || isLoading || (!!userId && !hasAttemptedFetch),
+    isInRoom: !!roomData,
+  }
+}

apps/web/src/lib/arcade/__tests__/arcade-session-integration.test.ts

@@ -8,6 +8,7 @@ import {
   deleteArcadeSession,
   getArcadeSession,
 } from '../session-manager'
+import { createRoom, deleteRoom } from '../room-manager'
 
 /**
  * Integration test for the full arcade session flow
@@ -16,6 +17,7 @@ import {
 describe('Arcade Session Integration', () => {
   const testUserId = 'integration-test-user'
   const testGuestId = 'integration-test-guest'
+  let testRoomId: string
 
   beforeEach(async () => {
     // Create test user
@@ -27,11 +29,25 @@ describe('Arcade Session Integration', () => {
         createdAt: new Date(),
       })
       .onConflictDoNothing()
+
+    // Create test room
+    const room = await createRoom({
+      name: 'Test Room',
+      createdBy: testGuestId,
+      creatorName: 'Test User',
+      gameName: 'matching',
+      gameConfig: { difficulty: 6, gameType: 'abacus-numeral', turnTimer: 30 },
+      ttlMinutes: 60,
+    })
+    testRoomId = room.id
   })
 
   afterEach(async () => {
     // Clean up
-    await deleteArcadeSession(testUserId)
+    await deleteArcadeSession(testGuestId)
+    if (testRoomId) {
+      await deleteRoom(testRoomId)
+    }
     await db.delete(schema.users).where(eq(schema.users.id, testUserId))
   })
 
@@ -45,12 +61,12 @@ describe('Arcade Session Integration', () => {
       difficulty: 6,
       turnTimer: 30,
       gamePhase: 'setup',
-      currentPlayer: "1",
+      currentPlayer: '1',
       matchedPairs: 0,
       totalPairs: 6,
       moves: 0,
       scores: {},
-      activePlayers: ["1"],
+      activePlayers: ['1'],
       consecutiveMatches: {},
       gameStartTime: null,
       gameEndTime: null,
@@ -63,11 +79,12 @@ describe('Arcade Session Integration', () => {
     }
 
     const session = await createArcadeSession({
-      userId: testUserId,
+      userId: testGuestId,
       gameName: 'matching',
       gameUrl: '/arcade/matching',
       initialState,
-      activePlayers: ["1"],
+      activePlayers: ['1'],
+      roomId: testRoomId,
     })
 
     expect(session).toBeDefined()
@@ -86,7 +103,7 @@ describe('Arcade Session Integration', () => {
       playerId: testUserId,
       timestamp: Date.now(),
       data: {
-        activePlayers: ["1"],
+        activePlayers: ['1'],
       },
     }
 
@@ -147,12 +164,12 @@ describe('Arcade Session Integration', () => {
       difficulty: 6,
       turnTimer: 30,
       gamePhase: 'playing',
-      currentPlayer: "1",
+      currentPlayer: '1',
       matchedPairs: 0,
       totalPairs: 6,
       moves: 0,
       scores: { 1: 0 },
-      activePlayers: ["1"],
+      activePlayers: ['1'],
       consecutiveMatches: { 1: 0 },
       gameStartTime: Date.now(),
       gameEndTime: null,
@@ -165,11 +182,12 @@ describe('Arcade Session Integration', () => {
     }
 
     await createArcadeSession({
-      userId: testUserId,
+      userId: testGuestId,
       gameName: 'matching',
       gameUrl: '/arcade/matching',
       initialState: playingState,
-      activePlayers: ["1"],
+      activePlayers: ['1'],
+      roomId: testRoomId,
     })
 
     // First move: flip card 1

apps/web/src/lib/arcade/__tests__/modal-rooms.test.ts

@@ -0,0 +1,281 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { eq } from 'drizzle-orm'
+import { db, schema } from '@/db'
+import { addRoomMember, getRoomMember, getUserRooms } from '../room-membership'
+import { createRoom, deleteRoom } from '../room-manager'
+
+/**
+ * Integration tests for modal room enforcement
+ *
+ * Tests the database-level unique constraint combined with application-level
+ * auto-leave logic to ensure users can only be in one room at a time.
+ */
+describe('Modal Room Enforcement', () => {
+  const testGuestId1 = 'modal-test-guest-1'
+  const testGuestId2 = 'modal-test-guest-2'
+  const testUserId1 = 'modal-test-user-1'
+  const testUserId2 = 'modal-test-user-2'
+  let room1Id: string
+  let room2Id: string
+  let room3Id: string
+
+  beforeEach(async () => {
+    // Create test users
+    await db
+      .insert(schema.users)
+      .values([
+        {
+          id: testUserId1,
+          guestId: testGuestId1,
+          createdAt: new Date(),
+        },
+        {
+          id: testUserId2,
+          guestId: testGuestId2,
+          createdAt: new Date(),
+        },
+      ])
+      .onConflictDoNothing()
+
+    // Create test rooms
+    const room1 = await createRoom({
+      name: 'Modal Test Room 1',
+      createdBy: testGuestId1,
+      creatorName: 'User 1',
+      gameName: 'matching',
+      gameConfig: { difficulty: 6 },
+      ttlMinutes: 60,
+    })
+    room1Id = room1.id
+
+    const room2 = await createRoom({
+      name: 'Modal Test Room 2',
+      createdBy: testGuestId1,
+      creatorName: 'User 1',
+      gameName: 'matching',
+      gameConfig: { difficulty: 8 },
+      ttlMinutes: 60,
+    })
+    room2Id = room2.id
+
+    const room3 = await createRoom({
+      name: 'Modal Test Room 3',
+      createdBy: testGuestId1,
+      creatorName: 'User 1',
+      gameName: 'memory-quiz',
+      gameConfig: {},
+      ttlMinutes: 60,
+    })
+    room3Id = room3.id
+  })
+
+  afterEach(async () => {
+    // Clean up
+    await db.delete(schema.roomMembers).where(eq(schema.roomMembers.userId, testGuestId1))
+    await db.delete(schema.roomMembers).where(eq(schema.roomMembers.userId, testGuestId2))
+
+    try {
+      await deleteRoom(room1Id)
+      await deleteRoom(room2Id)
+      await deleteRoom(room3Id)
+    } catch {
+      // Rooms may have been deleted in test
+    }
+
+    await db.delete(schema.users).where(eq(schema.users.id, testUserId1))
+    await db.delete(schema.users).where(eq(schema.users.id, testUserId2))
+  })
+
+  it('should allow user to join their first room', async () => {
+    const result = await addRoomMember({
+      roomId: room1Id,
+      userId: testGuestId1,
+      displayName: 'Test User',
+      isCreator: false,
+    })
+
+    expect(result.member).toBeDefined()
+    expect(result.member.roomId).toBe(room1Id)
+    expect(result.member.userId).toBe(testGuestId1)
+    expect(result.autoLeaveResult).toBeUndefined()
+
+    const userRooms = await getUserRooms(testGuestId1)
+    expect(userRooms).toHaveLength(1)
+    expect(userRooms[0]).toBe(room1Id)
+  })
+
+  it('should automatically leave previous room when joining new one', async () => {
+    // Join room 1
+    await addRoomMember({
+      roomId: room1Id,
+      userId: testGuestId1,
+      displayName: 'Test User',
+      isCreator: false,
+    })
+
+    let userRooms = await getUserRooms(testGuestId1)
+    expect(userRooms).toHaveLength(1)
+    expect(userRooms[0]).toBe(room1Id)
+
+    // Join room 2 (should auto-leave room 1)
+    const result = await addRoomMember({
+      roomId: room2Id,
+      userId: testGuestId1,
+      displayName: 'Test User',
+      isCreator: false,
+    })
+
+    expect(result.autoLeaveResult).toBeDefined()
+    expect(result.autoLeaveResult?.leftRooms).toHaveLength(1)
+    expect(result.autoLeaveResult?.leftRooms[0]).toBe(room1Id)
+    expect(result.autoLeaveResult?.previousRoomMembers).toHaveLength(1)
+
+    userRooms = await getUserRooms(testGuestId1)
+    expect(userRooms).toHaveLength(1)
+    expect(userRooms[0]).toBe(room2Id)
+
+    // Verify user is no longer in room 1
+    const room1Member = await getRoomMember(room1Id, testGuestId1)
+    expect(room1Member).toBeUndefined()
+
+    // Verify user is in room 2
+    const room2Member = await getRoomMember(room2Id, testGuestId1)
+    expect(room2Member).toBeDefined()
+  })
+
+  it('should handle rejoining the same room without auto-leave', async () => {
+    // Join room 1
+    const firstJoin = await addRoomMember({
+      roomId: room1Id,
+      userId: testGuestId1,
+      displayName: 'Test User',
+      isCreator: false,
+    })
+
+    expect(firstJoin.autoLeaveResult).toBeUndefined()
+
+    // "Rejoin" room 1 (should just update status)
+    const secondJoin = await addRoomMember({
+      roomId: room1Id,
+      userId: testGuestId1,
+      displayName: 'Test User Updated',
+      isCreator: false,
+    })
+
+    expect(secondJoin.autoLeaveResult).toBeUndefined()
+    expect(secondJoin.member.roomId).toBe(room1Id)
+
+    const userRooms = await getUserRooms(testGuestId1)
+    expect(userRooms).toHaveLength(1)
+    expect(userRooms[0]).toBe(room1Id)
+  })
+
+  it('should allow different users in different rooms simultaneously', async () => {
+    // User 1 joins room 1
+    await addRoomMember({
+      roomId: room1Id,
+      userId: testGuestId1,
+      displayName: 'User 1',
+      isCreator: false,
+    })
+
+    // User 2 joins room 2
+    await addRoomMember({
+      roomId: room2Id,
+      userId: testGuestId2,
+      displayName: 'User 2',
+      isCreator: false,
+    })
+
+    const user1Rooms = await getUserRooms(testGuestId1)
+    const user2Rooms = await getUserRooms(testGuestId2)
+
+    expect(user1Rooms).toHaveLength(1)
+    expect(user1Rooms[0]).toBe(room1Id)
+
+    expect(user2Rooms).toHaveLength(1)
+    expect(user2Rooms[0]).toBe(room2Id)
+  })
+
+  it('should auto-leave when switching between multiple rooms', async () => {
+    // Join room 1
+    await addRoomMember({
+      roomId: room1Id,
+      userId: testGuestId1,
+      displayName: 'Test User',
+    })
+
+    // Join room 2 (auto-leave room 1)
+    const result2 = await addRoomMember({
+      roomId: room2Id,
+      userId: testGuestId1,
+      displayName: 'Test User',
+    })
+    expect(result2.autoLeaveResult?.leftRooms).toContain(room1Id)
+
+    // Join room 3 (auto-leave room 2)
+    const result3 = await addRoomMember({
+      roomId: room3Id,
+      userId: testGuestId1,
+      displayName: 'Test User',
+    })
+    expect(result3.autoLeaveResult?.leftRooms).toContain(room2Id)
+
+    // Verify only in room 3
+    const userRooms = await getUserRooms(testGuestId1)
+    expect(userRooms).toHaveLength(1)
+    expect(userRooms[0]).toBe(room3Id)
+  })
+
+  it('should provide correct auto-leave metadata', async () => {
+    // Join room 1
+    await addRoomMember({
+      roomId: room1Id,
+      userId: testGuestId1,
+      displayName: 'Original Name',
+    })
+
+    // Join room 2 and check metadata
+    const result = await addRoomMember({
+      roomId: room2Id,
+      userId: testGuestId1,
+      displayName: 'New Name',
+    })
+
+    expect(result.autoLeaveResult).toBeDefined()
+    expect(result.autoLeaveResult?.previousRoomMembers).toHaveLength(1)
+
+    const previousMember = result.autoLeaveResult?.previousRoomMembers[0]
+    expect(previousMember?.roomId).toBe(room1Id)
+    expect(previousMember?.member.userId).toBe(testGuestId1)
+    expect(previousMember?.member.displayName).toBe('Original Name')
+  })
+
+  it('should enforce unique constraint at database level', async () => {
+    // This test verifies the database constraint catches issues even if
+    // application logic fails
+
+    // Join room 1
+    await addRoomMember({
+      roomId: room1Id,
+      userId: testGuestId1,
+      displayName: 'Test User',
+    })
+
+    // Try to directly insert a second membership (bypassing auto-leave logic)
+    const directInsert = async () => {
+      await db.insert(schema.roomMembers).values({
+        roomId: room2Id,
+        userId: testGuestId1,
+        displayName: 'Test User',
+        isCreator: false,
+        joinedAt: new Date(),
+        lastSeen: new Date(),
+        isOnline: true,
+      })
+    }
+
+    // Should fail due to unique constraint
+    await expect(directInsert()).rejects.toThrow()
+  })
+})

apps/web/src/lib/arcade/__tests__/orphaned-session-cleanup.test.ts

@@ -0,0 +1,199 @@
+import { eq } from 'drizzle-orm'
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { db, schema } from '@/db'
+import { createArcadeSession, deleteArcadeSession, getArcadeSession } from '../session-manager'
+import { createRoom, deleteRoom } from '../room-manager'
+
+/**
+ * Integration tests for orphaned session cleanup
+ *
+ * These tests ensure that sessions without valid rooms are properly
+ * cleaned up to prevent the bug where users get redirected to
+ * non-existent games when rooms have been TTL deleted.
+ */
+describe('Orphaned Session Cleanup', () => {
+  const testUserId = 'orphan-test-user-id'
+  const testGuestId = 'orphan-test-guest-id'
+  let testRoomId: string
+
+  beforeEach(async () => {
+    // Create test user
+    await db
+      .insert(schema.users)
+      .values({
+        id: testUserId,
+        guestId: testGuestId,
+        createdAt: new Date(),
+      })
+      .onConflictDoNothing()
+
+    // Create test room
+    const room = await createRoom({
+      name: 'Orphan Test Room',
+      createdBy: testGuestId,
+      creatorName: 'Test User',
+      gameName: 'matching',
+      gameConfig: { difficulty: 6, gameType: 'abacus-numeral', turnTimer: 30 },
+      ttlMinutes: 60,
+    })
+    testRoomId = room.id
+  })
+
+  afterEach(async () => {
+    // Clean up
+    await deleteArcadeSession(testGuestId)
+    if (testRoomId) {
+      try {
+        await deleteRoom(testRoomId)
+      } catch {
+        // Room may have been deleted in test
+      }
+    }
+    await db.delete(schema.users).where(eq(schema.users.id, testUserId))
+  })
+
+  it('should return undefined when session has no roomId', async () => {
+    // Create a session with a valid room
+    const session = await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: { gamePhase: 'setup' },
+      activePlayers: ['player-1'],
+      roomId: testRoomId,
+    })
+
+    expect(session).toBeDefined()
+    expect(session.roomId).toBe(testRoomId)
+
+    // Manually set roomId to null to simulate orphaned session
+    await db
+      .update(schema.arcadeSessions)
+      .set({ roomId: null })
+      .where(eq(schema.arcadeSessions.userId, testUserId))
+
+    // Getting the session should auto-delete it and return undefined
+    const result = await getArcadeSession(testGuestId)
+    expect(result).toBeUndefined()
+
+    // Verify session was actually deleted
+    const [directCheck] = await db
+      .select()
+      .from(schema.arcadeSessions)
+      .where(eq(schema.arcadeSessions.userId, testUserId))
+      .limit(1)
+
+    expect(directCheck).toBeUndefined()
+  })
+
+  it('should return undefined when session room has been deleted', async () => {
+    // Create a session with a valid room
+    const session = await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: { gamePhase: 'setup' },
+      activePlayers: ['player-1'],
+      roomId: testRoomId,
+    })
+
+    expect(session).toBeDefined()
+    expect(session.roomId).toBe(testRoomId)
+
+    // Delete the room (simulating TTL expiration)
+    await deleteRoom(testRoomId)
+
+    // Getting the session should detect missing room and auto-delete
+    const result = await getArcadeSession(testGuestId)
+    expect(result).toBeUndefined()
+
+    // Verify session was actually deleted
+    const [directCheck] = await db
+      .select()
+      .from(schema.arcadeSessions)
+      .where(eq(schema.arcadeSessions.userId, testUserId))
+      .limit(1)
+
+    expect(directCheck).toBeUndefined()
+  })
+
+  it('should return valid session when room exists', async () => {
+    // Create a session with a valid room
+    const session = await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: { gamePhase: 'setup' },
+      activePlayers: ['player-1'],
+      roomId: testRoomId,
+    })
+
+    expect(session).toBeDefined()
+
+    // Getting the session should work fine when room exists
+    const result = await getArcadeSession(testGuestId)
+    expect(result).toBeDefined()
+    expect(result?.roomId).toBe(testRoomId)
+    expect(result?.currentGame).toBe('matching')
+  })
+
+  it('should handle multiple getArcadeSession calls idempotently', async () => {
+    // Create a session with a valid room
+    await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: { gamePhase: 'setup' },
+      activePlayers: ['player-1'],
+      roomId: testRoomId,
+    })
+
+    // Delete the room
+    await deleteRoom(testRoomId)
+
+    // Multiple calls should all return undefined and not error
+    const result1 = await getArcadeSession(testGuestId)
+    const result2 = await getArcadeSession(testGuestId)
+    const result3 = await getArcadeSession(testGuestId)
+
+    expect(result1).toBeUndefined()
+    expect(result2).toBeUndefined()
+    expect(result3).toBeUndefined()
+  })
+
+  it('should prevent orphaned sessions from causing redirect loops', async () => {
+    /**
+     * Regression test for the specific bug:
+     * - Room gets TTL deleted
+     * - Session persists with null/invalid roomId
+     * - User visits /arcade
+     * - useArcadeRedirect finds the orphaned session
+     * - User gets redirected to /arcade/matching
+     * - But there's no valid game to play
+     *
+     * Fix: getArcadeSession should auto-delete orphaned sessions
+     */
+
+    // 1. Create session with room
+    await createArcadeSession({
+      userId: testGuestId,
+      gameName: 'matching',
+      gameUrl: '/arcade/matching',
+      initialState: { gamePhase: 'setup' },
+      activePlayers: ['player-1'],
+      roomId: testRoomId,
+    })
+
+    // 2. Room gets TTL deleted
+    await deleteRoom(testRoomId)
+
+    // 3. User's client checks for active session (like useArcadeRedirect does)
+    const activeSession = await getArcadeSession(testGuestId)
+
+    // 4. Should return undefined, preventing redirect
+    expect(activeSession).toBeUndefined()
+
+    // 5. User can now proceed to arcade lobby normally
+    // (no redirect to non-existent game)
+  })
+})

apps/web/src/lib/arcade/__tests__/room-manager.test.ts

@@ -0,0 +1,473 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { db, type schema } from '@/db'
+import {
+  cleanupExpiredRooms,
+  createRoom,
+  deleteRoom,
+  getRoomByCode,
+  getRoomById,
+  isRoomCreator,
+  listActiveRooms,
+  touchRoom,
+  updateRoom,
+  type CreateRoomOptions,
+} from '../room-manager'
+import * as roomCode from '../room-code'
+
+// Mock the database
+vi.mock('@/db', () => ({
+  db: {
+    query: {
+      arcadeRooms: {
+        findFirst: vi.fn(),
+        findMany: vi.fn(),
+      },
+    },
+    insert: vi.fn(),
+    update: vi.fn(),
+    delete: vi.fn(),
+  },
+  schema: {
+    arcadeRooms: {
+      id: 'id',
+      code: 'code',
+      name: 'name',
+      gameName: 'gameName',
+      isLocked: 'isLocked',
+      status: 'status',
+      lastActivity: 'lastActivity',
+    },
+    arcadeSessions: {
+      userId: 'userId',
+      roomId: 'roomId',
+    },
+  },
+}))
+
+// Mock room-code module
+vi.mock('../room-code', () => ({
+  generateRoomCode: vi.fn(),
+}))
+
+describe('Room Manager', () => {
+  const mockRoom: schema.ArcadeRoom = {
+    id: 'room-123',
+    code: 'ABC123',
+    name: 'Test Room',
+    createdBy: 'user-1',
+    creatorName: 'Test User',
+    createdAt: new Date(),
+    lastActivity: new Date(),
+    ttlMinutes: 60,
+    isLocked: false,
+    gameName: 'matching',
+    gameConfig: { difficulty: 6 },
+    status: 'lobby',
+    currentSessionId: null,
+    totalGamesPlayed: 0,
+  }
+
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  describe('createRoom', () => {
+    it('creates a room with generated code', async () => {
+      const options: CreateRoomOptions = {
+        name: 'Test Room',
+        createdBy: 'user-1',
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: { difficulty: 6 },
+      }
+
+      // Mock code generation
+      vi.mocked(roomCode.generateRoomCode).mockReturnValue('ABC123')
+
+      // Mock code uniqueness check
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(undefined)
+
+      // Mock insert
+      const mockInsert = {
+        values: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([mockRoom]),
+      }
+      vi.mocked(db.insert).mockReturnValue(mockInsert as any)
+
+      const room = await createRoom(options)
+
+      expect(room).toEqual(mockRoom)
+      expect(roomCode.generateRoomCode).toHaveBeenCalled()
+      expect(db.insert).toHaveBeenCalled()
+    })
+
+    it('retries code generation on collision', async () => {
+      const options: CreateRoomOptions = {
+        name: 'Test Room',
+        createdBy: 'user-1',
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: { difficulty: 6 },
+      }
+
+      // First code collides, second is unique
+      vi.mocked(roomCode.generateRoomCode)
+        .mockReturnValueOnce('ABC123')
+        .mockReturnValueOnce('XYZ789')
+
+      // First check finds collision, second check is unique
+      vi.mocked(db.query.arcadeRooms.findFirst)
+        .mockResolvedValueOnce(mockRoom) // Collision
+        .mockResolvedValueOnce(undefined) // Unique
+
+      const mockInsert = {
+        values: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([{ ...mockRoom, code: 'XYZ789' }]),
+      }
+      vi.mocked(db.insert).mockReturnValue(mockInsert as any)
+
+      const room = await createRoom(options)
+
+      expect(room.code).toBe('XYZ789')
+      expect(roomCode.generateRoomCode).toHaveBeenCalledTimes(2)
+    })
+
+    it('throws error after max collision attempts', async () => {
+      const options: CreateRoomOptions = {
+        name: 'Test Room',
+        createdBy: 'user-1',
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: { difficulty: 6 },
+      }
+
+      // All codes collide
+      vi.mocked(roomCode.generateRoomCode).mockReturnValue('ABC123')
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(mockRoom)
+
+      await expect(createRoom(options)).rejects.toThrow('Failed to generate unique room code')
+    })
+
+    it('sets default TTL to 60 minutes', async () => {
+      const options: CreateRoomOptions = {
+        name: 'Test Room',
+        createdBy: 'user-1',
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: { difficulty: 6 },
+      }
+
+      vi.mocked(roomCode.generateRoomCode).mockReturnValue('ABC123')
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(undefined)
+
+      const mockInsert = {
+        values: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([mockRoom]),
+      }
+      vi.mocked(db.insert).mockReturnValue(mockInsert as any)
+
+      const room = await createRoom(options)
+
+      expect(room.ttlMinutes).toBe(60)
+    })
+
+    it('respects custom TTL', async () => {
+      const options: CreateRoomOptions = {
+        name: 'Test Room',
+        createdBy: 'user-1',
+        creatorName: 'Test User',
+        gameName: 'matching',
+        gameConfig: { difficulty: 6 },
+        ttlMinutes: 120,
+      }
+
+      vi.mocked(roomCode.generateRoomCode).mockReturnValue('ABC123')
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(undefined)
+
+      const mockInsert = {
+        values: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([{ ...mockRoom, ttlMinutes: 120 }]),
+      }
+      vi.mocked(db.insert).mockReturnValue(mockInsert as any)
+
+      const room = await createRoom(options)
+
+      expect(room.ttlMinutes).toBe(120)
+    })
+  })
+
+  describe('getRoomById', () => {
+    it('returns room when found', async () => {
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(mockRoom)
+
+      const room = await getRoomById('room-123')
+
+      expect(room).toEqual(mockRoom)
+      expect(db.query.arcadeRooms.findFirst).toHaveBeenCalled()
+    })
+
+    it('returns undefined when not found', async () => {
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(undefined)
+
+      const room = await getRoomById('nonexistent')
+
+      expect(room).toBeUndefined()
+    })
+  })
+
+  describe('getRoomByCode', () => {
+    it('returns room when found', async () => {
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(mockRoom)
+
+      const room = await getRoomByCode('ABC123')
+
+      expect(room).toEqual(mockRoom)
+    })
+
+    it('converts code to uppercase', async () => {
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(mockRoom)
+
+      await getRoomByCode('abc123')
+
+      // Check that the where clause used uppercase
+      const call = vi.mocked(db.query.arcadeRooms.findFirst).mock.calls[0][0]
+      expect(call).toBeDefined()
+    })
+
+    it('returns undefined when not found', async () => {
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(undefined)
+
+      const room = await getRoomByCode('NONEXISTENT')
+
+      expect(room).toBeUndefined()
+    })
+  })
+
+  describe('updateRoom', () => {
+    it('updates room and returns updated data', async () => {
+      const updates = { name: 'Updated Room', isLocked: true }
+
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([{ ...mockRoom, ...updates }]),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      const room = await updateRoom('room-123', updates)
+
+      expect(room?.name).toBe('Updated Room')
+      expect(room?.isLocked).toBe(true)
+      expect(db.update).toHaveBeenCalled()
+    })
+
+    it('updates lastActivity timestamp', async () => {
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([mockRoom]),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      await updateRoom('room-123', { name: 'Updated' })
+
+      const setCall = mockUpdate.set.mock.calls[0][0]
+      expect(setCall).toHaveProperty('lastActivity')
+      expect(setCall.lastActivity).toBeInstanceOf(Date)
+    })
+  })
+
+  describe('touchRoom', () => {
+    it('updates lastActivity timestamp', async () => {
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      await touchRoom('room-123')
+
+      expect(db.update).toHaveBeenCalled()
+      const setCall = mockUpdate.set.mock.calls[0][0]
+      expect(setCall).toHaveProperty('lastActivity')
+      expect(setCall.lastActivity).toBeInstanceOf(Date)
+    })
+  })
+
+  describe('deleteRoom', () => {
+    it('deletes room from database', async () => {
+      const mockDelete = {
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.delete).mockReturnValue(mockDelete as any)
+
+      await deleteRoom('room-123')
+
+      expect(db.delete).toHaveBeenCalled()
+    })
+  })
+
+  describe('listActiveRooms', () => {
+    const activeRooms = [mockRoom, { ...mockRoom, id: 'room-456', name: 'Another Room' }]
+
+    it('returns active rooms', async () => {
+      vi.mocked(db.query.arcadeRooms.findMany).mockResolvedValue(activeRooms)
+
+      const rooms = await listActiveRooms()
+
+      expect(rooms).toEqual(activeRooms)
+      expect(rooms).toHaveLength(2)
+    })
+
+    it('filters by game name when provided', async () => {
+      vi.mocked(db.query.arcadeRooms.findMany).mockResolvedValue([mockRoom])
+
+      const rooms = await listActiveRooms('matching')
+
+      expect(rooms).toHaveLength(1)
+      expect(db.query.arcadeRooms.findMany).toHaveBeenCalled()
+    })
+
+    it('excludes locked rooms', async () => {
+      vi.mocked(db.query.arcadeRooms.findMany).mockResolvedValue(activeRooms)
+
+      await listActiveRooms()
+
+      // Verify the where clause excludes locked rooms
+      const call = vi.mocked(db.query.arcadeRooms.findMany).mock.calls[0][0]
+      expect(call).toBeDefined()
+    })
+
+    it('limits results to 50 rooms', async () => {
+      vi.mocked(db.query.arcadeRooms.findMany).mockResolvedValue(activeRooms)
+
+      await listActiveRooms()
+
+      const call = vi.mocked(db.query.arcadeRooms.findMany).mock.calls[0][0]
+      expect(call?.limit).toBe(50)
+    })
+  })
+
+  describe('cleanupExpiredRooms', () => {
+    it('deletes expired rooms', async () => {
+      const now = new Date()
+      const expiredRoom = {
+        ...mockRoom,
+        lastActivity: new Date(now.getTime() - 2 * 60 * 60 * 1000), // 2 hours ago
+        ttlMinutes: 60, // 1 hour TTL = expired
+      }
+
+      vi.mocked(db.query.arcadeRooms.findMany).mockResolvedValue([expiredRoom])
+
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      const mockDelete = {
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.delete).mockReturnValue(mockDelete as any)
+
+      const count = await cleanupExpiredRooms()
+
+      expect(count).toBe(1)
+      expect(db.update).toHaveBeenCalled() // Should clear roomId from sessions first
+      expect(db.delete).toHaveBeenCalled()
+    })
+
+    it('does not delete active rooms', async () => {
+      const now = new Date()
+      const activeRoom = {
+        ...mockRoom,
+        lastActivity: new Date(now.getTime() - 30 * 60 * 1000), // 30 min ago
+        ttlMinutes: 60, // 1 hour TTL = still active
+      }
+
+      vi.mocked(db.query.arcadeRooms.findMany).mockResolvedValue([activeRoom])
+
+      const count = await cleanupExpiredRooms()
+
+      expect(count).toBe(0)
+      expect(db.delete).not.toHaveBeenCalled()
+    })
+
+    it('handles mixed expired and active rooms', async () => {
+      const now = new Date()
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      const rooms = [
+        {
+          ...mockRoom,
+          id: 'expired-1',
+          lastActivity: new Date(now.getTime() - 2 * 60 * 60 * 1000),
+          ttlMinutes: 60,
+        },
+        {
+          ...mockRoom,
+          id: 'active-1',
+          lastActivity: new Date(now.getTime() - 30 * 60 * 1000),
+          ttlMinutes: 60,
+        },
+        {
+          ...mockRoom,
+          id: 'expired-2',
+          lastActivity: new Date(now.getTime() - 3 * 60 * 60 * 1000),
+          ttlMinutes: 120,
+        },
+      ]
+
+      vi.mocked(db.query.arcadeRooms.findMany).mockResolvedValue(rooms)
+
+      const mockDelete = {
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.delete).mockReturnValue(mockDelete as any)
+
+      const count = await cleanupExpiredRooms()
+
+      expect(count).toBe(2) // Only 2 expired rooms
+      expect(db.delete).toHaveBeenCalled()
+    })
+
+    it('returns 0 when no rooms exist', async () => {
+      vi.mocked(db.query.arcadeRooms.findMany).mockResolvedValue([])
+
+      const count = await cleanupExpiredRooms()
+
+      expect(count).toBe(0)
+      expect(db.delete).not.toHaveBeenCalled()
+    })
+  })
+
+  describe('isRoomCreator', () => {
+    it('returns true for room creator', async () => {
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(mockRoom)
+
+      const isCreator = await isRoomCreator('room-123', 'user-1')
+
+      expect(isCreator).toBe(true)
+    })
+
+    it('returns false for non-creator', async () => {
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(mockRoom)
+
+      const isCreator = await isRoomCreator('room-123', 'user-2')
+
+      expect(isCreator).toBe(false)
+    })
+
+    it('returns false when room not found', async () => {
+      vi.mocked(db.query.arcadeRooms.findFirst).mockResolvedValue(undefined)
+
+      const isCreator = await isRoomCreator('nonexistent', 'user-1')
+
+      expect(isCreator).toBe(false)
+    })
+  })
+})

apps/web/src/lib/arcade/__tests__/room-membership.test.ts

@@ -0,0 +1,377 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { db, type schema } from '@/db'
+import {
+  addRoomMember,
+  getOnlineMemberCount,
+  getOnlineRoomMembers,
+  getRoomMember,
+  getRoomMembers,
+  getUserRooms,
+  isMember,
+  removeAllMembers,
+  removeMember,
+  setMemberOnline,
+  touchMember,
+  type AddMemberOptions,
+} from '../room-membership'
+
+// Mock the database
+vi.mock('@/db', () => ({
+  db: {
+    query: {
+      roomMembers: {
+        findFirst: vi.fn(),
+        findMany: vi.fn(),
+      },
+    },
+    insert: vi.fn(),
+    update: vi.fn(),
+    delete: vi.fn(),
+  },
+  schema: {
+    roomMembers: {
+      id: 'id',
+      roomId: 'roomId',
+      userId: 'userId',
+      isOnline: 'isOnline',
+      joinedAt: 'joinedAt',
+    },
+  },
+}))
+
+describe('Room Membership', () => {
+  const mockMember: schema.RoomMember = {
+    id: 'member-123',
+    roomId: 'room-123',
+    userId: 'user-1',
+    displayName: 'Test User',
+    isCreator: false,
+    joinedAt: new Date(),
+    lastSeen: new Date(),
+    isOnline: true,
+  }
+
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  describe('addRoomMember', () => {
+    it('adds new member to room', async () => {
+      const options: AddMemberOptions = {
+        roomId: 'room-123',
+        userId: 'user-1',
+        displayName: 'Test User',
+      }
+
+      // No existing member
+      vi.mocked(db.query.roomMembers.findFirst).mockResolvedValue(undefined)
+
+      // Mock insert
+      const mockInsert = {
+        values: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([mockMember]),
+      }
+      vi.mocked(db.insert).mockReturnValue(mockInsert as any)
+
+      // Mock getUserRooms to return empty array (no existing rooms)
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue([])
+
+      const result = await addRoomMember(options)
+
+      expect(result.member).toEqual(mockMember)
+      expect(result.autoLeaveResult).toBeUndefined()
+      expect(db.insert).toHaveBeenCalled()
+    })
+
+    it('updates existing member instead of creating duplicate', async () => {
+      const options: AddMemberOptions = {
+        roomId: 'room-123',
+        userId: 'user-1',
+        displayName: 'Test User',
+      }
+
+      // Existing member found
+      const existingMember = { ...mockMember, isOnline: false }
+      vi.mocked(db.query.roomMembers.findFirst).mockResolvedValue(existingMember)
+
+      // Mock update
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([{ ...existingMember, isOnline: true }]),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      const result = await addRoomMember(options)
+
+      expect(result.member.isOnline).toBe(true)
+      expect(result.autoLeaveResult).toBeUndefined()
+      expect(db.update).toHaveBeenCalled()
+      expect(db.insert).not.toHaveBeenCalled()
+    })
+
+    it('sets isCreator flag when specified', async () => {
+      const options: AddMemberOptions = {
+        roomId: 'room-123',
+        userId: 'user-1',
+        displayName: 'Test User',
+        isCreator: true,
+      }
+
+      vi.mocked(db.query.roomMembers.findFirst).mockResolvedValue(undefined)
+
+      const mockInsert = {
+        values: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([{ ...mockMember, isCreator: true }]),
+      }
+      vi.mocked(db.insert).mockReturnValue(mockInsert as any)
+
+      // Mock getUserRooms to return empty array
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue([])
+
+      const result = await addRoomMember(options)
+
+      expect(result.member.isCreator).toBe(true)
+    })
+
+    it('sets isOnline to true by default', async () => {
+      const options: AddMemberOptions = {
+        roomId: 'room-123',
+        userId: 'user-1',
+        displayName: 'Test User',
+      }
+
+      vi.mocked(db.query.roomMembers.findFirst).mockResolvedValue(undefined)
+
+      const mockInsert = {
+        values: vi.fn().mockReturnThis(),
+        returning: vi.fn().mockResolvedValue([mockMember]),
+      }
+      vi.mocked(db.insert).mockReturnValue(mockInsert as any)
+
+      // Mock getUserRooms to return empty array
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue([])
+
+      const result = await addRoomMember(options)
+
+      expect(result.member.isOnline).toBe(true)
+    })
+  })
+
+  describe('getRoomMember', () => {
+    it('returns member when found', async () => {
+      vi.mocked(db.query.roomMembers.findFirst).mockResolvedValue(mockMember)
+
+      const member = await getRoomMember('room-123', 'user-1')
+
+      expect(member).toEqual(mockMember)
+    })
+
+    it('returns undefined when not found', async () => {
+      vi.mocked(db.query.roomMembers.findFirst).mockResolvedValue(undefined)
+
+      const member = await getRoomMember('room-123', 'user-999')
+
+      expect(member).toBeUndefined()
+    })
+  })
+
+  describe('getRoomMembers', () => {
+    const members = [
+      mockMember,
+      { ...mockMember, id: 'member-456', userId: 'user-2', displayName: 'User 2' },
+    ]
+
+    it('returns all members in room', async () => {
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue(members)
+
+      const result = await getRoomMembers('room-123')
+
+      expect(result).toEqual(members)
+      expect(result).toHaveLength(2)
+    })
+
+    it('returns empty array when no members', async () => {
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue([])
+
+      const result = await getRoomMembers('room-123')
+
+      expect(result).toEqual([])
+    })
+  })
+
+  describe('getOnlineRoomMembers', () => {
+    const onlineMembers = [
+      mockMember,
+      { ...mockMember, id: 'member-456', userId: 'user-2', isOnline: true },
+    ]
+
+    it('returns only online members', async () => {
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue(onlineMembers)
+
+      const result = await getOnlineRoomMembers('room-123')
+
+      expect(result).toEqual(onlineMembers)
+      expect(result.every((m) => m.isOnline)).toBe(true)
+    })
+
+    it('returns empty array when no online members', async () => {
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue([])
+
+      const result = await getOnlineRoomMembers('room-123')
+
+      expect(result).toEqual([])
+    })
+  })
+
+  describe('setMemberOnline', () => {
+    it('updates member online status to true', async () => {
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      await setMemberOnline('room-123', 'user-1', true)
+
+      expect(db.update).toHaveBeenCalled()
+      const setCall = mockUpdate.set.mock.calls[0][0]
+      expect(setCall.isOnline).toBe(true)
+      expect(setCall.lastSeen).toBeInstanceOf(Date)
+    })
+
+    it('updates member online status to false', async () => {
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      await setMemberOnline('room-123', 'user-1', false)
+
+      const setCall = mockUpdate.set.mock.calls[0][0]
+      expect(setCall.isOnline).toBe(false)
+    })
+
+    it('updates lastSeen timestamp', async () => {
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      await setMemberOnline('room-123', 'user-1', true)
+
+      const setCall = mockUpdate.set.mock.calls[0][0]
+      expect(setCall.lastSeen).toBeInstanceOf(Date)
+    })
+  })
+
+  describe('touchMember', () => {
+    it('updates lastSeen timestamp', async () => {
+      const mockUpdate = {
+        set: vi.fn().mockReturnThis(),
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.update).mockReturnValue(mockUpdate as any)
+
+      await touchMember('room-123', 'user-1')
+
+      expect(db.update).toHaveBeenCalled()
+      const setCall = mockUpdate.set.mock.calls[0][0]
+      expect(setCall.lastSeen).toBeInstanceOf(Date)
+    })
+  })
+
+  describe('removeMember', () => {
+    it('removes member from room', async () => {
+      const mockDelete = {
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.delete).mockReturnValue(mockDelete as any)
+
+      await removeMember('room-123', 'user-1')
+
+      expect(db.delete).toHaveBeenCalled()
+    })
+  })
+
+  describe('removeAllMembers', () => {
+    it('removes all members from room', async () => {
+      const mockDelete = {
+        where: vi.fn().mockReturnThis(),
+      }
+      vi.mocked(db.delete).mockReturnValue(mockDelete as any)
+
+      await removeAllMembers('room-123')
+
+      expect(db.delete).toHaveBeenCalled()
+    })
+  })
+
+  describe('getOnlineMemberCount', () => {
+    it('returns count of online members', async () => {
+      const onlineMembers = [
+        mockMember,
+        { ...mockMember, id: 'member-456', userId: 'user-2' },
+        { ...mockMember, id: 'member-789', userId: 'user-3' },
+      ]
+
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue(onlineMembers)
+
+      const count = await getOnlineMemberCount('room-123')
+
+      expect(count).toBe(3)
+    })
+
+    it('returns 0 when no online members', async () => {
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue([])
+
+      const count = await getOnlineMemberCount('room-123')
+
+      expect(count).toBe(0)
+    })
+  })
+
+  describe('isMember', () => {
+    it('returns true when user is member', async () => {
+      vi.mocked(db.query.roomMembers.findFirst).mockResolvedValue(mockMember)
+
+      const result = await isMember('room-123', 'user-1')
+
+      expect(result).toBe(true)
+    })
+
+    it('returns false when user is not member', async () => {
+      vi.mocked(db.query.roomMembers.findFirst).mockResolvedValue(undefined)
+
+      const result = await isMember('room-123', 'user-999')
+
+      expect(result).toBe(false)
+    })
+  })
+
+  describe('getUserRooms', () => {
+    it('returns list of room IDs user is member of', async () => {
+      const memberships = [
+        { ...mockMember, roomId: 'room-1' },
+        { ...mockMember, roomId: 'room-2' },
+        { ...mockMember, roomId: 'room-3' },
+      ]
+
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue(memberships)
+
+      const rooms = await getUserRooms('user-1')
+
+      expect(rooms).toEqual(['room-1', 'room-2', 'room-3'])
+    })
+
+    it('returns empty array when user has no rooms', async () => {
+      vi.mocked(db.query.roomMembers.findMany).mockResolvedValue([])
+
+      const rooms = await getUserRooms('user-1')
+
+      expect(rooms).toEqual([])
+    })
+  })
+})

apps/web/src/lib/arcade/__tests__/session-manager.test.ts

@@ -103,7 +103,8 @@ describe('session-manager', () => {
         gameName: 'matching',
         gameUrl: '/arcade/matching',
         initialState: {},
-        activePlayers: ["1"],
+        activePlayers: ['1'],
+        roomId: 'test-room-id',
       })
 
       // Verify user lookup by guestId
@@ -159,7 +160,8 @@ describe('session-manager', () => {
         gameName: 'matching',
         gameUrl: '/arcade/matching',
         initialState: {},
-        activePlayers: ["1"],
+        activePlayers: ['1'],
+        roomId: 'test-room-id',
       })
 
       // Verify user was created

apps/web/src/lib/arcade/player-manager.ts

@@ -0,0 +1,130 @@
+/**
+ * Player manager for arcade rooms
+ * Handles fetching and validating player participation in rooms
+ */
+
+import { and, eq } from 'drizzle-orm'
+import { db, schema } from '@/db'
+import type { Player } from '@/db/schema/players'
+
+/**
+ * Get all players for a user (regardless of isActive status)
+ * @param viewerId - The guestId from the cookie (same as what getViewerId() returns)
+ */
+export async function getAllPlayers(viewerId: string): Promise<Player[]> {
+  // First get the user record by guestId
+  const user = await db.query.users.findFirst({
+    where: eq(schema.users.guestId, viewerId),
+  })
+
+  if (!user) {
+    return []
+  }
+
+  // Now query all players by the actual user.id (no isActive filter)
+  return await db.query.players.findMany({
+    where: eq(schema.players.userId, user.id),
+    orderBy: schema.players.createdAt,
+  })
+}
+
+/**
+ * Get a user's active players (solo mode)
+ * These are the players that will participate when the user joins a solo game
+ * @param viewerId - The guestId from the cookie (same as what getViewerId() returns)
+ */
+export async function getActivePlayers(viewerId: string): Promise<Player[]> {
+  // First get the user record by guestId
+  const user = await db.query.users.findFirst({
+    where: eq(schema.users.guestId, viewerId),
+  })
+
+  if (!user) {
+    return []
+  }
+
+  // Now query players by the actual user.id
+  return await db.query.players.findMany({
+    where: and(eq(schema.players.userId, user.id), eq(schema.players.isActive, true)),
+    orderBy: schema.players.createdAt,
+  })
+}
+
+/**
+ * Get active players for all members in a room
+ * Returns only players marked isActive=true from each room member
+ * Returns a map of userId -> Player[]
+ */
+export async function getRoomActivePlayers(roomId: string): Promise<Map<string, Player[]>> {
+  // Get all room members
+  const members = await db.query.roomMembers.findMany({
+    where: eq(schema.roomMembers.roomId, roomId),
+  })
+
+  // Fetch active players for each member (respects isActive flag)
+  const playerMap = new Map<string, Player[]>()
+  for (const member of members) {
+    const players = await getActivePlayers(member.userId)
+    playerMap.set(member.userId, players)
+  }
+
+  return playerMap
+}
+
+/**
+ * Get all player IDs that should participate in a room game
+ * Flattens the player lists from all room members
+ */
+export async function getRoomPlayerIds(roomId: string): Promise<string[]> {
+  const playerMap = await getRoomActivePlayers(roomId)
+  const allPlayers: string[] = []
+
+  for (const players of playerMap.values()) {
+    allPlayers.push(...players.map((p) => p.id))
+  }
+
+  return allPlayers
+}
+
+/**
+ * Validate that a player ID belongs to a user who is a member of a room
+ */
+export async function validatePlayerInRoom(playerId: string, roomId: string): Promise<boolean> {
+  // Get the player
+  const player = await db.query.players.findFirst({
+    where: eq(schema.players.id, playerId),
+  })
+
+  if (!player) return false
+
+  // Check if the player's user is a member of the room
+  const member = await db.query.roomMembers.findFirst({
+    where: and(eq(schema.roomMembers.roomId, roomId), eq(schema.roomMembers.userId, player.userId)),
+  })
+
+  return !!member
+}
+
+/**
+ * Get player details by ID
+ */
+export async function getPlayer(playerId: string): Promise<Player | undefined> {
+  return await db.query.players.findFirst({
+    where: eq(schema.players.id, playerId),
+  })
+}
+
+/**
+ * Get multiple players by IDs
+ */
+export async function getPlayers(playerIds: string[]): Promise<Player[]> {
+  if (playerIds.length === 0) return []
+
+  const players: Player[] = []
+  for (const id of playerIds) {
+    const player = await getPlayer(id)
+    if (player) players.push(player)
+  }
+
+  return players
+}

apps/web/src/lib/arcade/room-membership.ts

@@ -13,16 +13,25 @@ export interface AddMemberOptions {
   isCreator?: boolean
 }
 
+export interface AutoLeaveResult {
+  leftRooms: string[] // Room IDs user was removed from
+  previousRoomMembers: Array<{ roomId: string; member: schema.RoomMember }>
+}
+
 /**
  * Add a member to a room
+ * Automatically removes user from any other rooms they're in (modal room enforcement)
+ * Returns the new membership and info about rooms that were auto-left
  */
-export async function addRoomMember(options: AddMemberOptions): Promise<schema.RoomMember> {
+export async function addRoomMember(
+  options: AddMemberOptions
+): Promise<{ member: schema.RoomMember; autoLeaveResult?: AutoLeaveResult }> {
   const now = new Date()
 
-  // Check if member already exists
+  // Check if member already exists in THIS room
   const existing = await getRoomMember(options.roomId, options.userId)
   if (existing) {
-    // Update lastSeen and isOnline
+    // Already in this room - just update status (no auto-leave needed)
     const [updated] = await db
       .update(schema.roomMembers)
       .set({
@@ -31,9 +40,35 @@ export async function addRoomMember(options: AddMemberOptions): Promise<schema.R
       })
       .where(eq(schema.roomMembers.id, existing.id))
       .returning()
-    return updated
+    return { member: updated }
   }
 
+  // AUTO-LEAVE LOGIC: Remove from all other rooms before joining this one
+  const currentRooms = await getUserRooms(options.userId)
+  const autoLeaveResult: AutoLeaveResult = {
+    leftRooms: [],
+    previousRoomMembers: [],
+  }
+
+  for (const roomId of currentRooms) {
+    if (roomId !== options.roomId) {
+      // Get member info before removing (for socket events)
+      const memberToRemove = await getRoomMember(roomId, options.userId)
+      if (memberToRemove) {
+        autoLeaveResult.previousRoomMembers.push({
+          roomId,
+          member: memberToRemove,
+        })
+      }
+
+      // Remove from room
+      await removeMember(roomId, options.userId)
+      autoLeaveResult.leftRooms.push(roomId)
+      console.log(`[Room Membership] Auto-left room ${roomId} for user ${options.userId}`)
+    }
+  }
+
+  // Now add to new room
   const newMember: schema.NewRoomMember = {
     roomId: options.roomId,
     userId: options.userId,
@@ -44,9 +79,29 @@ export async function addRoomMember(options: AddMemberOptions): Promise<schema.R
     isOnline: true,
   }
 
-  const [member] = await db.insert(schema.roomMembers).values(newMember).returning()
-  console.log('[Room Membership] Added member:', member.userId, 'to room:', member.roomId)
-  return member
+  try {
+    const [member] = await db.insert(schema.roomMembers).values(newMember).returning()
+    console.log('[Room Membership] Added member:', member.userId, 'to room:', member.roomId)
+
+    return {
+      member,
+      autoLeaveResult: autoLeaveResult.leftRooms.length > 0 ? autoLeaveResult : undefined,
+    }
+  } catch (error: any) {
+    // Handle unique constraint violation
+    // This should rarely happen due to auto-leave logic above, but catch it for safety
+    if (
+      error.code === 'SQLITE_CONSTRAINT' ||
+      error.message?.includes('UNIQUE') ||
+      error.message?.includes('unique')
+    ) {
+      console.error('[Room Membership] Unique constraint violation:', error.message)
+      throw new Error(
+        'ROOM_MEMBERSHIP_CONFLICT: User is already in another room. This should have been handled by auto-leave logic.'
+      )
+    }
+    throw error
+  }
 }
 
 /**

apps/web/src/lib/arcade/room-ttl-cleanup.ts

@@ -0,0 +1,58 @@
+/**
+ * Room TTL Cleanup Scheduler
+ * Periodically cleans up expired rooms
+ */
+
+import { cleanupExpiredRooms } from './room-manager'
+
+// Cleanup interval: run every 5 minutes
+const CLEANUP_INTERVAL_MS = 5 * 60 * 1000
+
+let cleanupInterval: NodeJS.Timeout | null = null
+
+/**
+ * Start the TTL cleanup scheduler
+ * Runs cleanup every 5 minutes
+ */
+export function startRoomTTLCleanup() {
+  if (cleanupInterval) {
+    console.log('[Room TTL] Cleanup scheduler already running')
+    return
+  }
+
+  console.log('[Room TTL] Starting cleanup scheduler (every 5 minutes)')
+
+  // Run immediately on start
+  cleanupExpiredRooms()
+    .then((count) => {
+      if (count > 0) {
+        console.log(`[Room TTL] Initial cleanup removed ${count} expired rooms`)
+      }
+    })
+    .catch((error) => {
+      console.error('[Room TTL] Initial cleanup failed:', error)
+    })
+
+  // Then run periodically
+  cleanupInterval = setInterval(async () => {
+    try {
+      const count = await cleanupExpiredRooms()
+      if (count > 0) {
+        console.log(`[Room TTL] Cleanup removed ${count} expired rooms`)
+      }
+    } catch (error) {
+      console.error('[Room TTL] Cleanup failed:', error)
+    }
+  }, CLEANUP_INTERVAL_MS)
+}
+
+/**
+ * Stop the TTL cleanup scheduler
+ */
+export function stopRoomTTLCleanup() {
+  if (cleanupInterval) {
+    clearInterval(cleanupInterval)
+    cleanupInterval = null
+    console.log('[Room TTL] Cleanup scheduler stopped')
+  }
+}

apps/web/src/lib/arcade/session-manager.ts

@@ -13,6 +13,7 @@ export interface CreateSessionOptions {
   gameUrl: string
   initialState: unknown
   activePlayers: string[] // Player IDs (UUIDs)
+  roomId: string // Required - sessions must be associated with a room
 }
 
 export interface SessionUpdateResult {
@@ -71,6 +72,7 @@ export async function createArcadeSession(
     gameUrl: options.gameUrl,
     gameState: options.initialState as any,
     activePlayers: options.activePlayers as any,
+    roomId: options.roomId, // Associate session with room
     startedAt: now,
     lastActivityAt: now,
     expiresAt,
@@ -96,8 +98,29 @@ export async function getArcadeSession(guestId: string): Promise<schema.ArcadeSe
     .where(eq(schema.arcadeSessions.userId, userId))
     .limit(1)
 
+  if (!session) return undefined
+
   // Check if session has expired
-  if (session && session.expiresAt < new Date()) {
+  if (session.expiresAt < new Date()) {
+    await deleteArcadeSession(guestId)
+    return undefined
+  }
+
+  // Check if session has a valid room association
+  // Sessions without rooms are orphaned and should be cleaned up
+  if (!session.roomId) {
+    console.log('[Session Manager] Deleting orphaned session without room:', session.userId)
+    await deleteArcadeSession(guestId)
+    return undefined
+  }
+
+  // Verify the room still exists
+  const room = await db.query.arcadeRooms.findFirst({
+    where: eq(schema.arcadeRooms.id, session.roomId),
+  })
+
+  if (!room) {
+    console.log('[Session Manager] Deleting session with non-existent room:', session.roomId)
     await deleteArcadeSession(guestId)
     return undefined
   }

apps/web/src/lib/socket-io.ts

@@ -0,0 +1,40 @@
+/**
+ * Socket.IO server instance accessor for API routes
+ * This module provides a way for API routes to access the socket.io server
+ * to broadcast real-time updates.
+ */
+
+import type { Server as SocketIOServerType } from 'socket.io'
+
+// Cache for the socket server module
+let socketServerModule: any = null
+
+/**
+ * Get the socket.io server instance
+ * Returns null if not initialized or if called on client-side
+ */
+export async function getSocketIO(): Promise<SocketIOServerType | null> {
+  // Client-side: return null
+  if (typeof window !== 'undefined') {
+    return null
+  }
+
+  // Lazy-load the socket server module on first call
+  if (!socketServerModule) {
+    try {
+      // Dynamic import to avoid bundling issues
+      socketServerModule = await import('../../socket-server')
+    } catch (error) {
+      console.error('[Socket IO] Failed to load socket server:', error)
+      return null
+    }
+  }
+
+  // Call the exported getSocketIO function from the module
+  if (socketServerModule && typeof socketServerModule.getSocketIO === 'function') {
+    return socketServerModule.getSocketIO()
+  }
+
+  console.warn('[Socket IO] getSocketIO function not found in socket-server module')
+  return null
+}

apps/web/src/stories/AbacusReact.progressive-test-suite.stories.tsx

@@ -49,9 +49,8 @@ const ProgressiveTestComponent: React.FC<{
 
     stepIndices.forEach((stepIndex, i) => {
       const description = fullInstruction.multiStepInstructions?.[i] || `Step ${i + 1}`
-      const stepBeads = fullInstruction.stepBeadHighlights?.filter(
-        (bead) => bead.stepIndex === stepIndex
-      ) || []
+      const stepBeads =
+        fullInstruction.stepBeadHighlights?.filter((bead) => bead.stepIndex === stepIndex) || []
 
       // Calculate the value change for this step by applying all bead movements
       let valueChange = 0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "soroban-monorepo",
-  "version": "2.3.1",
+  "version": "2.8.2",
   "private": true,
   "description": "Beautiful Soroban Flashcard Generator - Monorepo",
   "workspaces": [