diff --git a/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/.openspec.yaml b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/.openspec.yaml
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+schema: spec-driven
+created: 2026-05-17
diff --git a/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/design.md b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/design.md
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+## Context
+
+The current PokeR app implements Texas Hold'em poker but contains 10 critical bugs in its game flow logic. The core issues stem from three architectural problems: (1) ambiguous `currentBet` semantics that conflate "player contribution" with "bet matched," (2) lack of last-aggressor tracking for betting round completion, and (3) no side pot support for all-in scenarios. The hand evaluator and card systems are solid; the game orchestration layer needs complete reconstruction.
+
+## Goals / Non-Goals
+
+**Goals:**
+- Implement correct Texas Hold'em betting mechanics per official rules
+- Fix all identified bugs without introducing new ones
+- Support side pots for multi-player all-in scenarios
+- Prevent race conditions between human input and AI turns
+- Maintain existing Svelte 5 runes-based architecture and component structure
+
+**Non-Goals:**
+- Adding new game variants (Omaha, Stud, etc.)
+- Implementing GTO or strategic AI improvements
+- Multiplayer networking
+- Educational features (pot odds, hand ranges)
+- UI/visual redesign
+
+## Decisions
+
+### Decision 1: Separate `betMatched` flag from `currentBet`
+
+**Current:** `PlayerSeat.currentBet` serves dual purpose — tracks actual chips contributed AND whether player has matched the current bet level. This causes `applyCheck` to corrupt state by setting `currentBet = state.currentBet`.
+
+**Decision:** Add explicit `betMatched: boolean` field to `PlayerSeat`. `currentBet` becomes purely "chips contributed this round." Check simply sets `betMatched = true` without modifying chip counts.
+
+```
+PlayerSeat {
+  // ... existing fields
+  currentBet: number    // actual chips contributed this round
+  betMatched: boolean   // has player matched or checked this round?
+}
+```
+
+**Rationale:** Eliminates the fundamental semantic confusion that causes cascading bugs. Call amount becomes `state.currentBet - player.currentBet` with no corruption from check actions.
+
+### Decision 2: Last-aggressor betting round completion
+
+**Current:** `completeBettingRound` checks if all active players have `currentBet >= currentMaxBet`. This fails when all-in players are included and doesn't handle the "return to last aggressor" rule.
+
+**Decision:** Track `lastAggressorIndex` in GameState. A betting round ends when:
+- Action returns to `lastAggressorIndex` AND that player has matched, OR
+- All active (non-all-in) players have `betMatched = true`, OR
+- Only one active player remains
+
+```
+// Round completion logic
+function isRoundComplete(state): boolean {
+  const activePlayers = state.players.filter(p => p.status === 'active');
+  
+  // Single active player — round over
+  if (activePlayers.length <= 1) return true;
+  
+  // No raises occurred — everyone checked/called
+  if (state.lastAggressorIndex === -1) {
+    return activePlayers.every(p => p.betMatched);
+  }
+  
+  // Raises occurred — must return to last aggressor who matches
+  const lastAgg = state.players[state.lastAggressorIndex];
+  return lastAgg.status === 'active' && 
+         state.currentTurn === state.lastAggressorIndex && 
+         lastAgg.betMatched;
+}
+```
+
+**Rationale:** Texas Hold'em rules require action to return to the last aggressor. This is the standard implementation pattern used by poker software.
+
+### Decision 3: Side pot algorithm
+
+**Current:** No side pot support. All chips go into a single pot, causing incorrect distributions when players go all-in at different levels.
+
+**Decision:** Implement standard side pot calculation:
+1. Sort all-in players by their bet amount (ascending)
+2. Create pots from bottom up — each pot contains chips above the next lower all-in level
+3. Track which players are eligible for each pot (active or all-in at that level or above)
+
+```
+SidePot {
+  amount: number
+  eligiblePlayerIds: string[]
+}
+
+// Algorithm sketch:
+function calculatePots(players, currentPot): { mainPot: number, sidePots: SidePot[] }
+  // Sort players by bet amount
+  // Create nested pots from smallest all-in to largest
+  // Main pot = chips matched by all remaining active/all-in players
+```
+
+**Rationale:** Standard poker software approach. Keeps implementation clean and matches real-world rules exactly.
+
+### Decision 4: Unified game state machine in `+page.svelte`
+
+**Current:** `processGame()` has complex branching logic with async AI turns, state discarding, and multiple exit paths. Race conditions occur when human actions interrupt AI chains.
+
+**Decision:** Replace with a clear state machine pattern:
+- `aiActing: boolean` flag disables controls during AI turns
+- Single `processTurn()` function handles all post-action processing
+- State transitions are always applied atomically (`gameState = newState`)
+- AI turns use sequential promise chains, not nested timeouts
+
+```
+function processTurn() {
+  // 1. Check for early win (single active player)
+  // 2. Check if betting round is complete
+  // 3. If complete: advance to next stage or showdown
+  // 4. If not complete: check if next player is AI, schedule turn
+}
+
+// In handleAction:
+if (aiActing) return;  // Guard against race conditions
+gameState = applyAction(gameState, action);
+processTurn();
+```
+
+**Rationale:** Eliminates race conditions and state discarding bugs. Single source of truth for game flow logic.
+
+### Decision 5: Validation enforcement
+
+**Current:** `validateAction` exists but is never called by `applyRaise`, `applyFold`, etc. The AI and human actions bypass validation entirely.
+
+**Decision:** All action functions call `validateAction` internally and return unchanged state on invalid actions. The UI layer also validates before rendering buttons.
+
+```
+function applyRaise(state, playerId, amount) {
+  const validation = validateAction(playerId, 'raise', amount, state);
+  if (!validation.valid) return state;
+  // ... proceed with raise logic
+}
+```
+
+**Rationale:** Defense in depth — both the action layer and UI layer enforce rules. Prevents illegal states from being created.
+
+## Risks / Trade-offs
+
+[Side pot complexity] → Side pots add significant complexity to showdown logic. Mitigation: Thoroughly test with edge cases (2 all-ins, 3 all-ins, all-in on flop/turn/river).
+
+[State expansion] → Adding `betMatched`, `lastAggressorIndex`, and `sidePots` to GameState increases mutation surface. Mitigation: Use immutable state updates consistently, reset all fields in `startNewHand`.
+
+[AI timing changes] → Switching from nested timeouts to promise chains changes AI behavior timing. Mitigation: Keep 400ms delay per AI action for consistent feel.
+
+[Performance] → Side pot calculation at showdown could be expensive with many players. Mitigation: 6-max table limits complexity; algorithm is O(n log n) with n ≤ 6.
+
+[currentTurn deadlock] → `completeBettingRound` originally set `currentTurn = dealerPosition + 1`, which could land on a folded/all-in player, causing an infinite loop in the game state machine. Fixed by using `findFirstActivePlayer()` to always point to an active player.
+
+## Open Questions
+
+- Should we implement burn cards (standard in real poker, currently not implemented)?
+- How should all-in raises that don't constitute a full raise be handled (half-pot rule)?
+- Should the BB option (BB can check pre-flop if no raise) be explicitly documented in the UI?
diff --git a/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/proposal.md b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/proposal.md
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+## Why
+
+The current poker game logic contains multiple critical bugs that violate Texas Hold'em rules, causing rounds to skip, bets to calculate incorrectly, and chips to disappear. The game needs a complete rewrite of its core game flow to produce legitimate, playable poker.
+
+## What Changes
+
+- **Fix `applyCheck`**: Remove phantom chip assignment that corrupts call calculations and round completion
+- **Fix betting round completion**: Exclude all-in players from "all matched" check so active players aren't skipped
+- **Fix game loop state management**: Always apply returned state from `completeBettingRound` instead of discarding it when rounds don't advance
+- **Implement side pot support**: Create and distribute side pots when players go all-in at different levels
+- **Enforce minimum raise validation**: Call `validateAction` before applying any action, reject illegal raises
+- **Fix fold validation**: Allow folding in all situations per Texas Hold'em rules
+- **Fix pot distribution**: Award remainder chips to first winner instead of losing them
+- **Add input guardrails**: Disable player controls during AI turns to prevent race conditions
+- **Rewrite turn advancement**: Properly track last aggressor and end betting rounds when action returns correctly
+
+## Capabilities
+
+### New Capabilities
+- `side-pots`: Handle all-in scenarios by creating main pot and side pots with correct chip distribution among eligible players
+- `betting-round-flow`: Complete rewrite of betting round completion logic with proper last-aggressor tracking, all-in handling, and turn advancement
+- `game-loop-integrity`: Unified game state machine that prevents race conditions, always applies state transitions, and disables controls during AI turns
+
+### Modified Capabilities
+<!-- No existing specs to modify — this is a bug fix for fundamental game rules -->
+
+## Impact
+
+- `src/lib/game/actions.ts` — Complete rewrite of check, call, raise, fold, all-in functions
+- `src/lib/game/betting-round.ts` — Rewrite completion logic with side pot awareness and last-aggressor tracking
+- `src/lib/game/state.ts` — Add last aggressor tracking, side pot structures to GameState
+- `src/lib/types/game-state.ts` — Extend with `lastAggressor`, `sidePots`, betting round metadata
+- `src/lib/game/showdown.ts` — Fix pot distribution, handle side pots at showdown
+- `src/lib/game/validation.ts` — Fix fold validation, enforce minimum raise rules
+- `src/routes/+page.svelte` — Add input disabling during AI turns, proper state machine flow
+- `src/lib/game/turn.ts` — Rewrite turn advancement logic
diff --git a/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/betting-round-flow/spec.md b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/betting-round-flow/spec.md
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+++ b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/betting-round-flow/spec.md
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+## ADDED Requirements
+
+### Requirement: Check action does not modify player chip count or bet contribution
+When a player checks, the system SHALL only mark the player as having matched the current bet level without deducting chips or modifying their `currentBet` value.
+
+#### Scenario: Check with zero current bet
+- **WHEN** the current bet is 0 and Player A checks
+- **THEN** Player A's `betMatched` becomes true, `currentBet` remains unchanged, and chip count remains unchanged
+
+#### Scenario: Check after matching previous bet
+- **WHEN** Player A has already called a bet of 100 (currentBet = 100) and the next player checks (no raise occurred)
+- **THEN** Player A's state remains unchanged except `betMatched` is set to true
+
+### Requirement: Betting round completes when action returns to last aggressor
+The system SHALL end a betting round when all active players have matched the current bet and action returns to the position of the last player who raised or opened betting.
+
+#### Scenario: Pre-flop BB option (no raises)
+- **WHEN** SB posts 10, BB posts 20, and all players check around back to BB
+- **THEN** BB may check without posting additional chips, and the betting round completes
+
+#### Scenario: Raise requires action to return to raiser
+- **WHEN** Player A raises to 100, Players B and C call, and Player D checks
+- **THEN** the round does not complete until Player A either checks or faces no further raises
+
+### Requirement: All-in players are excluded from betting round completion check
+When determining if a betting round is complete, the system SHALL only consider active (non-all-in) players for the "all matched" condition.
+
+#### Scenario: Active player skipped by all-in completion bug
+- **WHEN** Player A bets 100, Player B goes all-in for 50, and Player C has not yet acted
+- **THEN** the betting round does NOT complete; Player C must act before the round advances
+
+#### Scenario: Single active player ends round
+- **WHEN** all players except one have folded or gone all-in
+- **THEN** the betting round completes immediately and the game proceeds to the next stage
+
+### Requirement: Turn advancement skips non-active players correctly
+The system SHALL advance turns to the next player with `status === 'active'`, skipping folded and all-in players.
+
+#### Scenario: Folded player is skipped
+- **WHEN** Player A folds and it's their turn position
+- **THEN** the turn advances to the next active player clockwise from Player A
+
+#### Scenario: All-in player is skipped during betting
+- **WHEN** Player B goes all-in during a betting round
+- **THEN** subsequent turns skip Player B and advance to the next active player
diff --git a/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/game-loop-integrity/spec.md b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/game-loop-integrity/spec.md
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+++ b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/game-loop-integrity/spec.md
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+## ADDED Requirements
+
+### Requirement: Game state transitions are always applied atomically
+The system SHALL always apply the complete returned state from action functions and never discard intermediate state updates.
+
+#### Scenario: Betting round completion state is preserved
+- **WHEN** `completeBettingRound` returns a new state with advanced `currentTurn` and reset bets
+- **THEN** the game applies the entire returned state, including turn advancement and bet resets, even if the betting round stage does not change
+
+#### Scenario: Action function results are never lost
+- **WHEN** a player performs any action (check, call, raise, fold, all-in)
+- **THEN** the returned state from the action function is applied completely before any subsequent processing occurs
+
+### Requirement: Player controls are disabled during AI turns
+The system SHALL disable human player input controls while AI players are taking their turns to prevent race conditions.
+
+#### Scenario: Human clicks during AI turn
+- **WHEN** an AI player is processing their turn (400ms delay) and the human player clicks a bet control
+- **THEN** the action is rejected, the UI shows disabled controls, and no state mutation occurs
+
+#### Scenario: Controls re-enable after AI turn completes
+- **WHEN** an AI player completes their action and the turn advances to the human player
+- **THEN** the bet controls become enabled and the human player may act
+
+### Requirement: Validation is enforced before applying any action
+The system SHALL validate all actions against game rules before applying state changes, returning unchanged state for invalid actions.
+
+#### Scenario: Invalid raise is rejected
+- **WHEN** a player attempts to raise below the minimum raise amount
+- **THEN** the action is rejected, the state remains unchanged, and an error reason is returned
+
+#### Scenario: Fold always permitted
+- **WHEN** a player attempts to fold during any betting round, including pre-flop
+- **THEN** the action is accepted regardless of current bet level
+
+### Requirement: Pot distribution preserves all chips
+When awarding pots to winners, the system SHALL distribute all chips without losing remainder amounts.
+
+#### Scenario: Odd pot split between two winners
+- **WHEN** the pot contains 105 chips and two players tie for the win
+- **THEN** one winner receives 53 chips, the other receives 52 chips, and zero chips are lost
+
+#### Scenario: Single winner receives full pot
+- **WHEN** a single player wins the pot of 200 chips
+- **THEN** the winner receives exactly 200 chips and the pot is reset to 0
diff --git a/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/side-pots/spec.md b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/side-pots/spec.md
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+++ b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/specs/side-pots/spec.md
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+## ADDED Requirements
+
+### Requirement: Side pots are created when players go all-in at different bet levels
+When one or more players go all-in for less than the current bet level, the system SHALL create separate side pots to ensure only eligible players can win chips they contributed to.
+
+#### Scenario: Single all-in creates main pot and side pot
+- **WHEN** Player A bets 100, Player B goes all-in for 50, and Player C calls 100
+- **THEN** a main pot of 150 (50×3) is created with all three players eligible, and a side pot of 100 (25×4) is created with Players A and C eligible
+
+#### Scenario: Multiple all-ins create multiple side pots
+- **WHEN** Player A bets 200, Player B goes all-in for 100, Player C goes all-in for 150, and Player D calls 200
+- **THEN** a main pot of 400 (100×4) is created with all players eligible, a side pot of 100 (50×3) is created with Players A, C, D eligible, and a side pot of 100 (50×2) is created with Players A and D eligible
+
+### Requirement: Side pots are awarded to eligible winners only
+When determining winners for each pot, the system SHALL only award a pot to players who contributed chips to that specific pot level.
+
+#### Scenario: All-in player wins main pot only
+- **WHEN** Player B is all-in for 50 and has the best hand at showdown, Player A and C are still active with worse hands
+- **THEN** Player B receives the main pot amount proportional to their contribution, and Players A/C compete for the side pot
+
+#### Scenario: All-in player loses all pots
+- **WHEN** Player B is all-in for 50 and has the worst hand at showdown
+- **THEN** Player B receives no chips from any pot, and eligible players split the main pot proportionally
+
+### Requirement: Side pot calculation handles edge cases correctly
+The system SHALL correctly calculate side pots when all players go all-in or when an all-in does not constitute a raise.
+
+#### Scenario: All players all-in creates single pot
+- **WHEN** all remaining players go all-in during a betting round
+- **THEN** a single main pot containing all chips is created with all players eligible, and no side pots are generated
+
+#### Scenario: All-in that doesn't raise does not create side pot
+- **WHEN** the current bet is 100 and Player B goes all-in for 80 (less than a full raise)
+- **THEN** no side pot is created; the main pot contains all chips and active players may check to continue
diff --git a/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/tasks.md b/openspec/changes/archive/2026-05-17-fix-texas-holdem-rules/tasks.md
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+## 1. Type system updates
+
+- [x] 1.1 Add `betMatched: boolean` field to `PlayerSeat` interface in `src/lib/types/player.ts`
+- [x] 1.2 Add `lastAggressorIndex: number` field to `GameState` interface in `src/lib/types/game-state.ts`
+- [x] 1.3 Define `SidePot` interface with `amount` and `eligiblePlayerIds` fields
+- [x] 1.4 Add `sidePots: SidePot[]` field to `GameState` interface
+
+## 2. State initialization & reset
+
+- [x] 2.1 Update `createInitialState` to initialize new fields (`betMatched`, `lastAggressorIndex`, `sidePots`)
+- [x] 2.2 Update `startNewHand` to reset all per-round fields including new fields
+- [x] 2.3 Update `postBlinds` to set `betMatched` correctly for SB and BB players
+
+## 3. Action function rewrites
+
+- [x] 3.1 Rewrite `applyCheck` to set `betMatched = true` without modifying `currentBet` or chips
+- [x] 3.2 Rewrite `applyCall` to use `state.currentBet - player.currentBet` for call amount with correct chip deduction
+- [x] 3.3 Rewrite `applyRaise` to update `lastAggressorIndex`, reset other players' `betMatched`, and enforce minimum raise
+- [x] 3.4 Rewrite `applyFold` to correctly mark player as folded and advance turn
+- [x] 3.5 Rewrite `applyAllIn` to handle partial all-in raises and update `lastAggressorIndex` if applicable
+- [x] 3.6 Add `validateAction` call at the start of each action function with early return on invalid actions
+
+## 4. Validation fixes
+
+- [x] 4.1 Fix fold validation to always permit folding (remove pre-flop restriction)
+- [x] 4.2 Fix raise validation to correctly calculate minimum raise based on `lastRaiseAmount`
+- [x] 4.3 Add validation for all-in actions that don't constitute a full raise
+
+## 5. Betting round completion rewrite
+
+- [x] 5.1 Implement `isRoundComplete` function with last-aggressor tracking logic
+- [x] 5.2 Rewrite `completeBettingRound` to use `betMatched` flag and exclude all-in players from match check
+- [x] 5.3 Implement BB option: allow BB to check pre-flop when no raises occurred
+- [x] 5.4 Ensure `currentTurn` advances correctly after round completion
+
+## 6. Side pot implementation
+
+- [x] 6.1 Implement `calculatePots` function to compute main pot and side pots from player bets
+- [x] 6.2 Integrate side pot calculation into all-in action handling
+- [x] 6.3 Update `awardPot` to distribute main pot and all side pots correctly
+- [x] 6.4 Fix remainder chip distribution (award leftover chips to first winner)
+- [x] 6.5 Update showdown logic to determine winners for each pot based on eligibility
+
+## 7. Turn advancement fixes
+
+- [x] 7.1 Rewrite `advanceTurn` to skip folded and all-in players correctly
+- [x] 7.2 Ensure turn advancement respects dealer position and betting round start position
+- [x] 7.3 Handle edge case where no active players remain for turn advancement
+
+## 8. Game loop rewrite (+page.svelte)
+
+- [x] 8.1 Add `aiActing: boolean` state flag to disable controls during AI turns
+- [x] 8.2 Replace `processGame` with unified `processTurn` state machine function
+- [x] 8.3 Ensure all state transitions apply returned state atomically (no discarding)
+- [x] 8.4 Convert AI turn timing from nested setTimeout to sequential promise chain
+- [x] 8.5 Add guard clause in `handleAction` to reject actions when `aiActing` is true
+- [x] 8.6 Update BetControls component to accept and respond to `disabled` prop
+
+## 9. Bug fixes discovered during playtesting
+
+- [x] 9.1 Fix deadlock: `completeBettingRound` sets `currentTurn` to first active player instead of hardcoded `dealerPosition + 1`
+- [x] 9.2 Simplify `processTurn` to use corrected `currentTurn` directly after round completion
+
+## 10. Testing & verification
+
+- [ ] 10.1 Test pre-flop betting round with all action combinations (check, call, raise, fold)
+- [ ] 10.2 Test single all-in scenario verifies correct main pot and side pot creation
+- [ ] 10.3 Test multiple all-ins at different levels verifies correct multi-side pot distribution
+- [ ] 10.4 Test BB option pre-flop (BB checks when no raises)
+- [ ] 10.5 Test full hand flow from deal through showdown with no state corruption
+- [ ] 10.6 Test race condition prevention (rapid human clicks during AI turn are rejected)
\ No newline at end of file
diff --git a/openspec/specs/betting-round-flow/spec.md b/openspec/specs/betting-round-flow/spec.md
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+# betting-round-flow Specification
+
+## Purpose
+TBD - created by archiving change fix-texas-holdem-rules. Update Purpose after archive.
+## Requirements
+### Requirement: Check action does not modify player chip count or bet contribution
+When a player checks, the system SHALL only mark the player as having matched the current bet level without deducting chips or modifying their `currentBet` value.
+
+#### Scenario: Check with zero current bet
+- **WHEN** the current bet is 0 and Player A checks
+- **THEN** Player A's `betMatched` becomes true, `currentBet` remains unchanged, and chip count remains unchanged
+
+#### Scenario: Check after matching previous bet
+- **WHEN** Player A has already called a bet of 100 (currentBet = 100) and the next player checks (no raise occurred)
+- **THEN** Player A's state remains unchanged except `betMatched` is set to true
+
+### Requirement: Betting round completes when action returns to last aggressor
+The system SHALL end a betting round when all active players have matched the current bet and action returns to the position of the last player who raised or opened betting.
+
+#### Scenario: Pre-flop BB option (no raises)
+- **WHEN** SB posts 10, BB posts 20, and all players check around back to BB
+- **THEN** BB may check without posting additional chips, and the betting round completes
+
+#### Scenario: Raise requires action to return to raiser
+- **WHEN** Player A raises to 100, Players B and C call, and Player D checks
+- **THEN** the round does not complete until Player A either checks or faces no further raises
+
+### Requirement: All-in players are excluded from betting round completion check
+When determining if a betting round is complete, the system SHALL only consider active (non-all-in) players for the "all matched" condition.
+
+#### Scenario: Active player skipped by all-in completion bug
+- **WHEN** Player A bets 100, Player B goes all-in for 50, and Player C has not yet acted
+- **THEN** the betting round does NOT complete; Player C must act before the round advances
+
+#### Scenario: Single active player ends round
+- **WHEN** all players except one have folded or gone all-in
+- **THEN** the betting round completes immediately and the game proceeds to the next stage
+
+### Requirement: Turn advancement skips non-active players correctly
+The system SHALL advance turns to the next player with `status === 'active'`, skipping folded and all-in players.
+
+#### Scenario: Folded player is skipped
+- **WHEN** Player A folds and it's their turn position
+- **THEN** the turn advances to the next active player clockwise from Player A
+
+#### Scenario: All-in player is skipped during betting
+- **WHEN** Player B goes all-in during a betting round
+- **THEN** subsequent turns skip Player B and advance to the next active player
+
diff --git a/openspec/specs/game-loop-integrity/spec.md b/openspec/specs/game-loop-integrity/spec.md
new file mode 100644
index 0000000..1e93481
--- /dev/null
+++ b/openspec/specs/game-loop-integrity/spec.md
@@ -0,0 +1,49 @@
+# game-loop-integrity Specification
+
+## Purpose
+TBD - created by archiving change fix-texas-holdem-rules. Update Purpose after archive.
+## Requirements
+### Requirement: Game state transitions are always applied atomically
+The system SHALL always apply the complete returned state from action functions and never discard intermediate state updates.
+
+#### Scenario: Betting round completion state is preserved
+- **WHEN** `completeBettingRound` returns a new state with advanced `currentTurn` and reset bets
+- **THEN** the game applies the entire returned state, including turn advancement and bet resets, even if the betting round stage does not change
+
+#### Scenario: Action function results are never lost
+- **WHEN** a player performs any action (check, call, raise, fold, all-in)
+- **THEN** the returned state from the action function is applied completely before any subsequent processing occurs
+
+### Requirement: Player controls are disabled during AI turns
+The system SHALL disable human player input controls while AI players are taking their turns to prevent race conditions.
+
+#### Scenario: Human clicks during AI turn
+- **WHEN** an AI player is processing their turn (400ms delay) and the human player clicks a bet control
+- **THEN** the action is rejected, the UI shows disabled controls, and no state mutation occurs
+
+#### Scenario: Controls re-enable after AI turn completes
+- **WHEN** an AI player completes their action and the turn advances to the human player
+- **THEN** the bet controls become enabled and the human player may act
+
+### Requirement: Validation is enforced before applying any action
+The system SHALL validate all actions against game rules before applying state changes, returning unchanged state for invalid actions.
+
+#### Scenario: Invalid raise is rejected
+- **WHEN** a player attempts to raise below the minimum raise amount
+- **THEN** the action is rejected, the state remains unchanged, and an error reason is returned
+
+#### Scenario: Fold always permitted
+- **WHEN** a player attempts to fold during any betting round, including pre-flop
+- **THEN** the action is accepted regardless of current bet level
+
+### Requirement: Pot distribution preserves all chips
+When awarding pots to winners, the system SHALL distribute all chips without losing remainder amounts.
+
+#### Scenario: Odd pot split between two winners
+- **WHEN** the pot contains 105 chips and two players tie for the win
+- **THEN** one winner receives 53 chips, the other receives 52 chips, and zero chips are lost
+
+#### Scenario: Single winner receives full pot
+- **WHEN** a single player wins the pot of 200 chips
+- **THEN** the winner receives exactly 200 chips and the pot is reset to 0
+
diff --git a/openspec/specs/side-pots/spec.md b/openspec/specs/side-pots/spec.md
new file mode 100644
index 0000000..f0bc314
--- /dev/null
+++ b/openspec/specs/side-pots/spec.md
@@ -0,0 +1,38 @@
+# side-pots Specification
+
+## Purpose
+TBD - created by archiving change fix-texas-holdem-rules. Update Purpose after archive.
+## Requirements
+### Requirement: Side pots are created when players go all-in at different bet levels
+When one or more players go all-in for less than the current bet level, the system SHALL create separate side pots to ensure only eligible players can win chips they contributed to.
+
+#### Scenario: Single all-in creates main pot and side pot
+- **WHEN** Player A bets 100, Player B goes all-in for 50, and Player C calls 100
+- **THEN** a main pot of 150 (50×3) is created with all three players eligible, and a side pot of 100 (25×4) is created with Players A and C eligible
+
+#### Scenario: Multiple all-ins create multiple side pots
+- **WHEN** Player A bets 200, Player B goes all-in for 100, Player C goes all-in for 150, and Player D calls 200
+- **THEN** a main pot of 400 (100×4) is created with all players eligible, a side pot of 100 (50×3) is created with Players A, C, D eligible, and a side pot of 100 (50×2) is created with Players A and D eligible
+
+### Requirement: Side pots are awarded to eligible winners only
+When determining winners for each pot, the system SHALL only award a pot to players who contributed chips to that specific pot level.
+
+#### Scenario: All-in player wins main pot only
+- **WHEN** Player B is all-in for 50 and has the best hand at showdown, Player A and C are still active with worse hands
+- **THEN** Player B receives the main pot amount proportional to their contribution, and Players A/C compete for the side pot
+
+#### Scenario: All-in player loses all pots
+- **WHEN** Player B is all-in for 50 and has the worst hand at showdown
+- **THEN** Player B receives no chips from any pot, and eligible players split the main pot proportionally
+
+### Requirement: Side pot calculation handles edge cases correctly
+The system SHALL correctly calculate side pots when all players go all-in or when an all-in does not constitute a raise.
+
+#### Scenario: All players all-in creates single pot
+- **WHEN** all remaining players go all-in during a betting round
+- **THEN** a single main pot containing all chips is created with all players eligible, and no side pots are generated
+
+#### Scenario: All-in that doesn't raise does not create side pot
+- **WHEN** the current bet is 100 and Player B goes all-in for 80 (less than a full raise)
+- **THEN** no side pot is created; the main pot contains all chips and active players may check to continue
+
diff --git a/src/lib/components/BetControls.svelte b/src/lib/components/BetControls.svelte
index 0f83f65..62ce3d9 100644
--- a/src/lib/components/BetControls.svelte
+++ b/src/lib/components/BetControls.svelte
@@ -1,13 +1,15 @@
 <script lang="ts">
   import type { GameState } from '$lib/types/game-state';
 
-  let { gameState, onAction }: {
+  let { gameState, onAction, disabled = false }: {
     gameState: GameState;
     onAction: (type: string, amount?: number) => void;
+    disabled?: boolean;
   } = $props();
 
   const humanPlayer = $derived(gameState.players[0]);
   const isMyTurn = $derived(
+    !disabled &&
     gameState.currentTurn === 0 &&
     humanPlayer?.status === 'active' &&
     gameState.bettingRound !== 'idle' &&
@@ -38,7 +40,7 @@
         type="number"
         bind:value={raiseAmount}
         min={minRaise}
-        max={humanPlayer?.chips + humanPlayer?.currentBet ?? 0}
+        max={humanPlayer.chips + humanPlayer.currentBet}
         class="raise-input"
         aria-label="Raise amount"
       />
diff --git a/src/lib/game/actions.ts b/src/lib/game/actions.ts
index 5f429ca..54b415f 100644
--- a/src/lib/game/actions.ts
+++ b/src/lib/game/actions.ts
@@ -1,6 +1,8 @@
 import type { GameState } from '$lib/types/game-state';
+import type { ActionType } from '$lib/types/action';
+import { validateAction } from './validation';
 
-function recordActionForState(state: GameState, playerId: string, type: string, amount?: number): GameState {
+function recordActionForState(state: GameState, playerId: string, type: ActionType, amount?: number): GameState {
   return {
     ...state,
     actionHistory: [
@@ -27,15 +29,30 @@ function advanceTurn(state: GameState): number {
   return state.currentTurn;
 }
 
+function resetBetMatched(state: GameState, excludePlayerId?: string): GameState {
+  const updatedPlayers = state.players.map(p => {
+    if (p.id === excludePlayerId) return p;
+    if (p.status === 'active') return { ...p, betMatched: false };
+    return p;
+  });
+  return { ...state, players: updatedPlayers };
+}
+
 export function applyCheck(state: GameState, playerId: string): GameState {
+  const validation = validateAction(playerId, 'check', undefined, state);
+  if (!validation.valid) return state;
+
   const playerIdx = state.players.findIndex(p => p.id === playerId);
   const updatedPlayers = [...state.players];
-  updatedPlayers[playerIdx] = { ...updatedPlayers[playerIdx], currentBet: state.currentBet };
+  updatedPlayers[playerIdx] = { ...updatedPlayers[playerIdx], betMatched: true };
   const result = recordActionForState({ ...state, players: updatedPlayers }, playerId, 'check', 0);
   return { ...result, currentTurn: advanceTurn(result) };
 }
 
 export function applyCall(state: GameState, playerId: string): GameState {
+  const validation = validateAction(playerId, 'call', undefined, state);
+  if (!validation.valid) return state;
+
   const playerIdx = state.players.findIndex(p => p.id === playerId);
   const player = state.players[playerIdx];
   const callAmount = Math.min(state.currentBet - player.currentBet, player.chips);
@@ -43,6 +60,7 @@ export function applyCall(state: GameState, playerId: string): GameState {
   const newPlayer = { ...updatedPlayers[playerIdx] };
   newPlayer.chips -= callAmount;
   newPlayer.currentBet += callAmount;
+  newPlayer.betMatched = true;
   if (newPlayer.chips === 0 && callAmount > 0) {
     newPlayer.status = 'all-in';
   }
@@ -52,16 +70,29 @@ export function applyCall(state: GameState, playerId: string): GameState {
 }
 
 export function applyRaise(state: GameState, playerId: string, amount: number): GameState {
+  const validation = validateAction(playerId, 'raise', amount, state);
+  if (!validation.valid) return state;
+
   const playerIdx = state.players.findIndex(p => p.id === playerId);
   const player = state.players[playerIdx];
   const totalBet = Math.min(amount, player.chips + player.currentBet);
   const added = totalBet - player.currentBet;
   const raiseOverCurrent = totalBet - state.currentBet;
 
-  const updatedPlayers = [...state.players];
+  let newState: GameState = {
+    ...state,
+    currentBet: totalBet,
+    lastRaiseAmount: raiseOverCurrent > 0 ? raiseOverCurrent : state.lastRaiseAmount,
+    lastAggressorIndex: playerIdx
+  };
+
+  newState = resetBetMatched(newState, playerId);
+
+  const updatedPlayers = [...newState.players];
   const newPlayer = { ...updatedPlayers[playerIdx] };
   newPlayer.chips -= added;
   newPlayer.currentBet = totalBet;
+  newPlayer.betMatched = true;
   if (newPlayer.chips === 0 && added > 0) {
     newPlayer.status = 'all-in';
   }
@@ -69,11 +100,9 @@ export function applyRaise(state: GameState, playerId: string, amount: number):
 
   const result = recordActionForState(
     {
-      ...state,
+      ...newState,
       players: updatedPlayers,
-      pot: state.pot + added,
-      currentBet: totalBet,
-      lastRaiseAmount: raiseOverCurrent > 0 ? raiseOverCurrent : state.lastRaiseAmount
+      pot: newState.pot + added
     },
     playerId,
     'raise',
@@ -83,6 +112,9 @@ export function applyRaise(state: GameState, playerId: string, amount: number):
 }
 
 export function applyFold(state: GameState, playerId: string): GameState {
+  const validation = validateAction(playerId, 'fold', undefined, state);
+  if (!validation.valid) return state;
+
   const playerIdx = state.players.findIndex(p => p.id === playerId);
   const updatedPlayers = [...state.players];
   updatedPlayers[playerIdx] = { ...updatedPlayers[playerIdx], status: 'folded' as const };
@@ -91,23 +123,39 @@ export function applyFold(state: GameState, playerId: string): GameState {
 }
 
 export function applyAllIn(state: GameState, playerId: string): GameState {
+  const validation = validateAction(playerId, 'all-in', undefined, state);
+  if (!validation.valid) return state;
+
   const playerIdx = state.players.findIndex(p => p.id === playerId);
   const player = state.players[playerIdx];
   const amount = player.chips;
+  const totalBet = player.currentBet + amount;
+  const raiseOverCurrent = totalBet - state.currentBet;
 
-  const updatedPlayers = [...state.players];
+  let newState: GameState = { ...state };
+  if (raiseOverCurrent > 0) {
+    newState = {
+      ...newState,
+      currentBet: totalBet,
+      lastRaiseAmount: Math.max(raiseOverCurrent, state.lastRaiseAmount),
+      lastAggressorIndex: playerIdx
+    };
+    newState = resetBetMatched(newState, playerId);
+  }
+
+  const updatedPlayers = [...newState.players];
   const newPlayer = { ...updatedPlayers[playerIdx] };
   newPlayer.chips = 0;
-  newPlayer.currentBet += amount;
+  newPlayer.currentBet = totalBet;
   newPlayer.status = 'all-in';
+  newPlayer.betMatched = true;
   updatedPlayers[playerIdx] = newPlayer;
 
-  const newCurrentBet = Math.max(state.currentBet, newPlayer.currentBet);
   const result = recordActionForState(
-    { ...state, players: updatedPlayers, pot: state.pot + amount, currentBet: newCurrentBet },
+    { ...newState, players: updatedPlayers, pot: newState.pot + amount },
     playerId,
     'all-in',
     amount
   );
   return { ...result, currentTurn: advanceTurn(result) };
-}
+}
\ No newline at end of file
diff --git a/src/lib/game/betting-round.ts b/src/lib/game/betting-round.ts
index e4cc7cf..bf761f9 100644
--- a/src/lib/game/betting-round.ts
+++ b/src/lib/game/betting-round.ts
@@ -1,17 +1,40 @@
 import type { GameState } from '$lib/types/game-state';
 
-export function completeBettingRound(state: GameState): GameState {
-  const activePlayers = state.players.filter(p => p.status === 'active' || p.status === 'all-in');
+export function isRoundComplete(state: GameState): boolean {
+  const activePlayers = state.players.filter(p => p.status === 'active');
+
   if (activePlayers.length <= 1) {
-    return state;
+    return true;
   }
 
-  const currentMaxBet = state.currentBet;
-  const allMatched = activePlayers.every(
-    p => p.status === 'all-in' || p.currentBet >= currentMaxBet
-  );
+  if (state.lastAggressorIndex === -1) {
+    return activePlayers.every(p => p.betMatched);
+  }
 
-  if (!allMatched) {
+  const lastAgg = state.players[state.lastAggressorIndex];
+  if (lastAgg.status !== 'active') {
+    return activePlayers.every(p => p.betMatched);
+  }
+
+  return state.currentTurn === state.lastAggressorIndex && lastAgg.betMatched;
+}
+
+function findFirstActivePlayer(state: GameState): number {
+  const numPlayers = state.players.length;
+  let pos = (state.dealerPosition + 1) % numPlayers;
+  let checked = 0;
+  while (checked < numPlayers) {
+    if (state.players[pos].status === 'active') {
+      return pos;
+    }
+    pos = (pos + 1) % numPlayers;
+    checked++;
+  }
+  return state.dealerPosition;
+}
+
+export function completeBettingRound(state: GameState): GameState {
+  if (!isRoundComplete(state)) {
     return state;
   }
 
@@ -35,15 +58,18 @@ export function completeBettingRound(state: GameState): GameState {
 
   const resetPlayers = state.players.map(p => {
     if (p.status === 'folded' || p.status === 'all-in') return p;
-    return { ...p, currentBet: 0 };
+    return { ...p, currentBet: 0, betMatched: false };
   });
 
+  const nextTurn = findFirstActivePlayer(state);
+
   return {
     ...state,
     players: resetPlayers,
     bettingRound: nextRound,
     currentBet: 0,
     lastRaiseAmount: 0,
-    currentTurn: (state.dealerPosition + 1) % state.players.length
+    lastAggressorIndex: -1,
+    currentTurn: nextTurn
   };
-}
+}
\ No newline at end of file
diff --git a/src/lib/game/blinds.ts b/src/lib/game/blinds.ts
index ddfa249..f9f8f1f 100644
--- a/src/lib/game/blinds.ts
+++ b/src/lib/game/blinds.ts
@@ -9,12 +9,14 @@ export function postBlinds(state: GameState): GameState {
   const sbPlayer = { ...newState.players[sbIndex] };
   sbPlayer.chips -= state.smallBlind;
   sbPlayer.currentBet = state.smallBlind;
+  sbPlayer.betMatched = false;
   newState.players = [...newState.players];
   newState.players[sbIndex] = sbPlayer;
 
   const bbPlayer = { ...newState.players[bbIndex] };
   bbPlayer.chips -= state.bigBlind;
   bbPlayer.currentBet = state.bigBlind;
+  bbPlayer.betMatched = false;
   newState.players[bbIndex] = bbPlayer;
 
   newState.pot = state.smallBlind + state.bigBlind;
diff --git a/src/lib/game/hand.ts b/src/lib/game/hand.ts
index f63b3d6..381fe0d 100644
--- a/src/lib/game/hand.ts
+++ b/src/lib/game/hand.ts
@@ -8,11 +8,12 @@ export function startNewHand(state: GameState): GameState {
   let newState = rotateDealer(state);
 
   const deck = shuffleDeck(createDeck());
-  newState = { ...newState, deck, communityCards: [], pot: 0, actionHistory: [] };
+  newState = { ...newState, deck, communityCards: [], pot: 0, actionHistory: [], lastAggressorIndex: -1, sidePots: [] };
 
   const resetPlayers = newState.players.map(p => ({
     ...p,
     currentBet: 0,
+    betMatched: false,
     status: p.chips > 0 ? 'active' as const : p.status,
     holeCards: []
   }));
diff --git a/src/lib/game/pots.ts b/src/lib/game/pots.ts
new file mode 100644
index 0000000..85ee073
--- /dev/null
+++ b/src/lib/game/pots.ts
@@ -0,0 +1,38 @@
+import type { GameState, SidePot } from '$lib/types/game-state';
+
+export function calculatePots(state: GameState): { mainPot: number; sidePots: SidePot[] } {
+  const nonFolded = state.players.filter(p => p.status !== 'folded');
+  if (nonFolded.length === 0) return { mainPot: state.pot, sidePots: [] };
+
+  const sortedByBet = [...nonFolded].sort((a, b) => a.currentBet - b.currentBet);
+
+  const allInPlayers = nonFolded.filter(p => p.status === 'all-in');
+  if (allInPlayers.length === 0 || allInPlayers.length === nonFolded.length) {
+    return { mainPot: state.pot, sidePots: [] };
+  }
+
+  const sidePots: SidePot[] = [];
+  let previousLevel = 0;
+
+  for (let i = 0; i < allInPlayers.length; i++) {
+    const player = sortedByBet.find(p => p.status === 'all-in' && p.currentBet >= allInPlayers[i].currentBet)!;
+    const currentLevel = player.currentBet;
+    const diff = currentLevel - previousLevel;
+
+    if (diff <= 0) continue;
+
+    const eligible = nonFolded.filter(p => p.currentBet >= currentLevel || p.status === 'all-in');
+    const potAmount = eligible.length * diff;
+
+    if (i < allInPlayers.length - 1) {
+      sidePots.push({ amount: potAmount, eligiblePlayerIds: eligible.map(p => p.id) });
+    } else {
+      sidePots.push({ amount: potAmount, eligiblePlayerIds: eligible.map(p => p.id) });
+    }
+
+    previousLevel = currentLevel;
+  }
+
+  const mainPotAmount = state.pot - sidePots.reduce((sum, sp) => sum + sp.amount, 0);
+  return { mainPot: Math.max(0, mainPotAmount), sidePots };
+}
\ No newline at end of file
diff --git a/src/lib/game/showdown.ts b/src/lib/game/showdown.ts
index 558de5e..38bb867 100644
--- a/src/lib/game/showdown.ts
+++ b/src/lib/game/showdown.ts
@@ -1,6 +1,7 @@
-import type { GameState } from '$lib/types/game-state';
+import type { GameState, SidePot } from '$lib/types/game-state';
 import { evaluateHand } from '$lib/utils/hand-evaluator';
 import { compareHands } from '$lib/utils/ranks';
+import { calculatePots } from './pots';
 
 export interface ShowdownResult {
   winners: string[];
@@ -25,7 +26,7 @@ export function determineWinner(state: GameState): ShowdownResult {
   }
 
   let bestResult = handResults.values().next().value;
-  for (const [id, result] of handResults) {
+  for (const [, result] of handResults) {
     if (compareHands(result, bestResult!) > 0) {
       bestResult = result;
     }
@@ -41,11 +42,46 @@ export function determineWinner(state: GameState): ShowdownResult {
   return { winners, handResults };
 }
 
+function awardSinglePot(potAmount: number, eligibleWinners: string[]): { chipAwards: Map<string, number>; remainder: number } {
+  const awards = new Map<string, number>();
+  if (eligibleWinners.length === 0) return { chipAwards: awards, remainder: potAmount };
+
+  const share = Math.floor(potAmount / eligibleWinners.length);
+  let distributed = 0;
+
+  for (let i = 0; i < eligibleWinners.length; i++) {
+    const winnerId = eligibleWinners[i];
+    const amount = i === eligibleWinners.length - 1 ? potAmount - distributed : share;
+    awards.set(winnerId, (awards.get(winnerId) || 0) + amount);
+    distributed += amount;
+  }
+
+  return { chipAwards: awards, remainder: 0 };
+}
+
 export function awardPot(state: GameState, winners: string[]): GameState {
-  const share = Math.floor(state.pot / winners.length);
+  const { mainPot, sidePots } = calculatePots(state);
+
+  const allAwards = new Map<string, number>();
+
+  const eligibleMainWinners = winners;
+  const { chipAwards: mainAwards } = awardSinglePot(mainPot, eligibleMainWinners.length > 0 ? eligibleMainWinners : winners);
+  for (const [id, amount] of mainAwards) {
+    allAwards.set(id, (allAwards.get(id) || 0) + amount);
+  }
+
+  for (const sidePot of sidePots) {
+    const eligibleWinners = winners.filter(id => sidePot.eligiblePlayerIds.includes(id));
+    const { chipAwards: sideAwards } = awardSinglePot(sidePot.amount, eligibleWinners.length > 0 ? eligibleWinners : sidePot.eligiblePlayerIds.slice(0, 1));
+    for (const [id, amount] of sideAwards) {
+      allAwards.set(id, (allAwards.get(id) || 0) + amount);
+    }
+  }
+
   const updatedPlayers = state.players.map(p => {
-    if (winners.includes(p.id)) {
-      return { ...p, chips: p.chips + share };
+    const award = allAwards.get(p.id) || 0;
+    if (award > 0) {
+      return { ...p, chips: p.chips + award };
     }
     return p;
   });
@@ -53,6 +89,7 @@ export function awardPot(state: GameState, winners: string[]): GameState {
   return {
     ...state,
     players: updatedPlayers,
-    pot: 0
+    pot: 0,
+    sidePots: []
   };
-}
+}
\ No newline at end of file
diff --git a/src/lib/game/state.ts b/src/lib/game/state.ts
index 66c322a..6a93842 100644
--- a/src/lib/game/state.ts
+++ b/src/lib/game/state.ts
@@ -10,6 +10,7 @@ export function createInitialState(numPlayers: number, startingStack: number): G
       name: i === 0 ? 'You' : `Bot ${i}`,
       chips: startingStack,
       currentBet: 0,
+      betMatched: false,
       status: 'active',
       holeCards: [],
       position: i
@@ -28,7 +29,9 @@ export function createInitialState(numPlayers: number, startingStack: number): G
     currentBet: 0,
     lastRaiseAmount: 0,
     smallBlind: 10,
-    bigBlind: 20
+    bigBlind: 20,
+    lastAggressorIndex: -1,
+    sidePots: []
   };
 }
 
diff --git a/src/lib/game/turn.ts b/src/lib/game/turn.ts
index a402e55..0c31058 100644
--- a/src/lib/game/turn.ts
+++ b/src/lib/game/turn.ts
@@ -16,3 +16,19 @@ export function getNextActivePlayer(state: GameState): number | null {
 
   return null;
 }
+
+export function getFirstActivePlayerLeftOfDealer(state: GameState): number | null {
+  const numPlayers = state.players.length;
+  let pos = (state.dealerPosition + 1) % numPlayers;
+  let checked = 0;
+
+  while (checked < numPlayers) {
+    if (state.players[pos].status === 'active') {
+      return pos;
+    }
+    pos = (pos + 1) % numPlayers;
+    checked++;
+  }
+
+  return null;
+}
\ No newline at end of file
diff --git a/src/lib/game/validation.ts b/src/lib/game/validation.ts
index 6e3f108..9a7d6c7 100644
--- a/src/lib/game/validation.ts
+++ b/src/lib/game/validation.ts
@@ -23,11 +23,10 @@ export function validateAction(
     case 'call': {
       const callAmount = state.currentBet - player.currentBet;
       if (callAmount <= 0) return { valid: false, reason: 'Nothing to call' };
-      if (player.chips < callAmount && player.chips > 0) {
+      if (player.chips > 0) {
         return { valid: true };
       }
-      if (player.chips < callAmount) return { valid: false, reason: 'Not enough chips' };
-      return { valid: true };
+      return { valid: false, reason: 'Not enough chips' };
     }
 
     case 'raise': {
@@ -36,21 +35,24 @@ export function validateAction(
         ? state.currentBet + state.lastRaiseAmount
         : state.currentBet + state.bigBlind;
       if (amount < minRaise) return { valid: false, reason: `Minimum raise is ${minRaise}` };
-      if (player.chips - player.currentBet < amount) return { valid: false, reason: 'Not enough chips' };
+      const totalNeeded = amount - player.currentBet;
+      if (totalNeeded > player.chips) return { valid: false, reason: 'Not enough chips' };
       return { valid: true };
     }
 
     case 'fold':
-      if (state.currentBet <= player.currentBet && state.bettingRound !== 'pre-flop') {
-        return { valid: false, reason: 'Cannot check; use fold or check' };
-      }
       return { valid: true };
 
-    case 'all-in':
+    case 'all-in': {
       if (player.chips <= 0) return { valid: false, reason: 'No chips remaining' };
+      const allInTotal = player.chips + player.currentBet;
+      if (allInTotal <= state.currentBet) {
+        return { valid: false, reason: 'All-in amount does not exceed current bet' };
+      }
       return { valid: true };
+    }
 
     default:
       return { valid: false, reason: 'Unknown action' };
   }
-}
+}
\ No newline at end of file
diff --git a/src/lib/types/game-state.ts b/src/lib/types/game-state.ts
index 74564a5..5709908 100644
--- a/src/lib/types/game-state.ts
+++ b/src/lib/types/game-state.ts
@@ -4,6 +4,11 @@ import type { ActionRecord } from './action';
 
 export type BettingRound = 'pre-flop' | 'flop' | 'turn' | 'river' | 'showdown' | 'idle';
 
+export interface SidePot {
+  amount: number;
+  eligiblePlayerIds: string[];
+}
+
 export interface GameState {
   deck: Card[];
   players: PlayerSeat[];
@@ -17,4 +22,6 @@ export interface GameState {
   lastRaiseAmount: number;
   smallBlind: number;
   bigBlind: number;
+  lastAggressorIndex: number;
+  sidePots: SidePot[];
 }
diff --git a/src/lib/types/player.ts b/src/lib/types/player.ts
index f190d5f..6050138 100644
--- a/src/lib/types/player.ts
+++ b/src/lib/types/player.ts
@@ -7,6 +7,7 @@ export interface PlayerSeat {
   name: string;
   chips: number;
   currentBet: number;
+  betMatched: boolean;
   status: PlayerStatus;
   holeCards: Card[];
   position: number;
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index a77f9e8..89790c6 100644
--- a/src/routes/+page.svelte
+++ b/src/routes/+page.svelte
@@ -4,7 +4,7 @@
   import { createInitialState, rotateDealer } from '$lib/game/state';
   import { startNewHand } from '$lib/game/hand';
   import { applyCheck, applyCall, applyRaise, applyFold, applyAllIn } from '$lib/game/actions';
-  import { completeBettingRound } from '$lib/game/betting-round';
+  import { completeBettingRound, isRoundComplete } from '$lib/game/betting-round';
   import { dealCommunityCards } from '$lib/game/dealing';
   import { determineWinner, awardPot } from '$lib/game/showdown';
 
@@ -12,13 +12,17 @@
   let gameState = $state(startNewHand(initialState));
 
   let message = $state('');
+  let aiActing = $state(false);
 
-  const initialTurn = gameState.currentTurn;
-  if (initialTurn !== 0) {
-    setTimeout(() => aiAct(), 100);
+  function checkInitialTurn() {
+    if (gameState.currentTurn !== 0) {
+      setTimeout(() => aiAct(), 100);
+    }
   }
+  checkInitialTurn();
 
   function handleAction(type: string, amount?: number) {
+    if (aiActing) return;
     if (gameState.bettingRound === 'idle' || gameState.bettingRound === 'showdown') return;
 
     let newState: typeof gameState;
@@ -42,25 +46,29 @@
         return;
     }
 
+    if (newState === gameState) return;
+
     gameState = { ...newState };
-    processGame();
+    processTurn();
   }
 
-  function processGame() {
+  function processTurn() {
+    if (gameState.bettingRound === 'idle' || gameState.bettingRound === 'showdown') return;
+
     const activeCount = gameState.players.filter(p => p.status === 'active' || p.status === 'all-in').length;
 
     if (activeCount <= 1) {
       const winner = gameState.players.find(p => p.status !== 'folded')!;
       gameState = awardPot(gameState, [winner.id]);
       gameState.bettingRound = 'showdown';
-      message = `${winner.name} wins $${gameState.pot > 0 ? gameState.pot : 'the pot'}!`;
+      message = `${winner.name} wins the pot!`;
       return;
     }
 
-    let processed = completeBettingRound(gameState);
-
-    if (processed.bettingRound !== gameState.bettingRound) {
+    if (isRoundComplete(gameState)) {
+      const processed = completeBettingRound(gameState);
       gameState = { ...processed };
+
       if (gameState.bettingRound === 'flop') {
         const { deck, cards } = dealCommunityCards(gameState.deck, 3);
         gameState.deck = deck;
@@ -74,73 +82,90 @@
       if (gameState.bettingRound === 'showdown') {
         const { winners } = determineWinner(gameState);
         gameState = awardPot(gameState, winners);
-        message = `${winners.map(id => gameState.players.find(p => p.id === id)?.name).join(', ')} wins!`;
-      } else {
-        const canBet = gameState.players.some(p => p.status === 'active');
-        if (canBet && gameState.currentTurn !== 0) {
-          aiAct();
-        } else if (!canBet) {
-          setTimeout(() => processGame(), 300);
-        }
+        const winnerNames = winners.map(id => gameState.players.find(p => p.id === id)?.name).filter(Boolean);
+        message = `${winnerNames.join(', ')} wins!`;
+        return;
+      }
+
+      if (gameState.currentTurn !== 0) {
+        aiAct();
       }
       return;
     }
 
-    const canBet = gameState.players.some(p => p.status === 'active');
-    if (!canBet) {
-      setTimeout(() => processGame(), 300);
-    } else if (gameState.currentTurn !== 0) {
-      aiAct();
+    if (gameState.currentTurn !== 0) {
+      const nextPlayer = gameState.players[gameState.currentTurn];
+      if (nextPlayer && nextPlayer.status === 'active') {
+        aiAct();
+      }
     }
   }
 
-  function aiAct() {
-    let aiIndex = gameState.currentTurn;
+ async function aiAct() {
+    aiActing = true;
 
-    if (aiIndex === 0) return;
+    await new Promise(resolve => setTimeout(resolve, 400));
+
+    const aiIndex = gameState.currentTurn;
+    if (aiIndex === 0) {
+      aiActing = false;
+      return;
+    }
 
     const aiPlayer = gameState.players[aiIndex];
-    if (!aiPlayer || aiPlayer.status !== 'active') return;
+    if (!aiPlayer || aiPlayer.status !== 'active') {
+      aiActing = false;
+      processTurn();
+      return;
+    }
 
-    setTimeout(() => {
-      const actions: string[] = [];
-      if (aiPlayer.currentBet >= gameState.currentBet) actions.push('check');
-      else actions.push('call');
+    const actions: string[] = [];
+    if (aiPlayer.currentBet >= gameState.currentBet) actions.push('check');
+    else actions.push('call');
 
-      if (aiPlayer.chips > gameState.currentBet - aiPlayer.currentBet + gameState.bigBlind) {
-        actions.push('raise');
-      }
-      if (Math.random() < 0.15) actions.push('fold');
+    if (aiPlayer.chips > gameState.currentBet - aiPlayer.currentBet + gameState.bigBlind) {
+      actions.push('raise');
+    }
+    if (Math.random() < 0.15) actions.push('fold');
 
-      const action = actions[Math.floor(Math.random() * actions.length)];
+    const action = actions[Math.floor(Math.random() * actions.length)];
 
-      let newState: typeof gameState;
-      switch (action) {
-        case 'check':
-          newState = applyCheck(gameState, aiPlayer.id);
-          break;
-        case 'call':
-          newState = applyCall(gameState, aiPlayer.id);
-          break;
-        case 'raise':
-          const raiseAmt = Math.min(gameState.currentBet + gameState.bigBlind, aiPlayer.chips + aiPlayer.currentBet);
-          newState = applyRaise(gameState, aiPlayer.id, raiseAmt);
-          break;
-        case 'fold':
-          newState = applyFold(gameState, aiPlayer.id);
-          break;
-        default:
-          newState = applyCall(gameState, aiPlayer.id);
-      }
+    let newState: typeof gameState;
+    switch (action) {
+      case 'check':
+        newState = applyCheck(gameState, aiPlayer.id);
+        break;
+      case 'call':
+        newState = applyCall(gameState, aiPlayer.id);
+        break;
+      case 'raise':
+        const raiseAmt = Math.min(gameState.currentBet + gameState.bigBlind, aiPlayer.chips + aiPlayer.currentBet);
+        newState = applyRaise(gameState, aiPlayer.id, raiseAmt);
+        break;
+      case 'fold':
+        newState = applyFold(gameState, aiPlayer.id);
+        break;
+      default:
+        newState = applyCall(gameState, aiPlayer.id);
+    }
 
+    if (newState !== gameState) {
       gameState = { ...newState };
-      processGame();
-    }, 400);
+    }
+
+    aiActing = false;
+    processTurn();
   }
 
   function startNextHand() {
     message = '';
+    aiActing = false;
     gameState = startNewHand(gameState);
+
+    const initialTurn = gameState.currentTurn;
+    if (initialTurn !== 0) {
+      setTimeout(() => aiAct(), 100);
+    }
   }
 </script>
 
@@ -152,7 +177,7 @@
 
   <PokerTable {gameState} />
 
-  <BetControls {gameState} onAction={handleAction} />
+  <BetControls {gameState} onAction={handleAction} disabled={aiActing} />
 
   {#if message}
     <div class="message" role="alert">{message}</div>
@@ -216,4 +241,4 @@
     background: #27ae60;
     transform: translateY(-1px);
   }
-</style>
+</style>
\ No newline at end of file