Game winner

src/ai/simulate/graphs/spec-processing-graph/nodes/extract-instructions/prompts.ts

@@ -133,8 +133,8 @@ Rules & Guidance:
        - Runtime will automatically compute game.winningPlayers from these flags
        - Example stateChanges:
          * Single winner: "set winning player's isGameWinner to true"
-         * Tie/multiple winners: "set both/all winning players' isGameWinner to true"
-         * No winner/draw: "leave all isGameWinner flags false (default)"
+         * Tie/multiple winners: "set ALL players tied for the win isGameWinner to true"
+         * No winner/abandoned game: "explicitly set ALL players' isGameWinner to false"
        - Can be set before gameEnded (e.g., player meets win condition mid-game)
        - MUST be set on all paths leading to the "finished" phase (except no-winner scenarios)
        - ⚠️ Validation will fail if any path to "finished" doesn't set isGameWinner appropriately
@@ -464,25 +464,42 @@ Common variable patterns:
 - Example: {{ "op": "set", "path": "game.gameEnded", "value": true }}
 - Missing this will cause validation failure: "No transition sets game.gameEnded=true"
 
-**players.{{{{playerId}}}}.isGameWinner** (boolean) - Set to true for winning player(s):
-- ⚠️ CRITICAL: MUST be set on ALL paths to the "finished" phase (except no-winner scenarios)
-- Set to true for each player who won the game
-- Leave as false (default) for players who didn't win or in draw scenarios
+**players.{{{{playerId}}}}.isGameWinner** (boolean) - MUST be set in game-ending transitions:
+- ⚠️ CRITICAL: At least ONE transition MUST set isGameWinner (validation will fail otherwise)
+- ⚠️ CRITICAL: Set isGameWinner on ALL paths leading to "finished" phase (including no-winner 
+  scenarios)
 - Runtime automatically computes game.winningPlayers array from these flags
 - Can be set in same transition as gameEnded OR in an earlier transition
-- Examples:
-  * Single winner: {{ "op": "set", "path": "players.{{{{winnerId}}}}.isGameWinner", "value": true }}
-  * Multiple winners (tie): Two ops - {{ "op": "set", "path": "players.{{{{player1Id}}}}.isGameWinner", "value": true }} and {{ "op": "set", "path": "players.{{{{player2Id}}}}.isGameWinner", "value": true }}
-  * No winner (draw/abandoned): No operations needed - all flags remain false
-- Missing this will cause validation failure: "Path [phases] does not set isGameWinner"
+- **DO NOT** leave isGameWinner unset - validation requires explicit set operations
 - If game has multiple ending scenarios, EACH ending transition must set isGameWinner appropriately
 
-**Example: Complete game-ending transition stateDelta (sets BOTH required fields)**:
+**Complete Examples (game-ending transitions with BOTH required fields):**
+
+Single Winner:
 {{
   "stateDelta": [
     {{ "op": "set", "path": "players.{{{{winnerId}}}}.isGameWinner", "value": true }},
     {{ "op": "set", "path": "game.gameEnded", "value": true }},
-    {{ "op": "set", "path": "game.publicMessage", "value": "Game Over! {{{{winnerName}}}} wins!" }}
+    {{ "op": "set", "path": "game.publicMessage", "value": "{{{{winnerName}}}} wins!" }}
+  ]
+}}
+
+Tie (Multiple Winners - ALL tied players set to true):
+{{
+  "stateDelta": [
+    {{ "op": "set", "path": "players.{{{{player1Id}}}}.isGameWinner", "value": true }},
+    {{ "op": "set", "path": "players.{{{{player2Id}}}}.isGameWinner", "value": true }},
+    {{ "op": "set", "path": "game.gameEnded", "value": true }},
+    {{ "op": "set", "path": "game.publicMessage", "value": "It's a tie! Both players win!" }}
+  ]
+}}
+
+No Winner (Abandoned/Stalemate - explicitly set ALL to false):
+{{
+  "stateDelta": [
+    {{ "op": "setForAllPlayers", "field": "isGameWinner", "value": false }},
+    {{ "op": "set", "path": "game.gameEnded", "value": true }},
+    {{ "op": "set", "path": "game.publicMessage", "value": "Game ended with no winner." }}
   ]
 }}
 

src/ai/simulate/graphs/spec-processing-graph/nodes/extract-instructions/validators.ts

@@ -1008,8 +1008,8 @@ export async function validateGameCompletion(
       );
     }
 
-    // Check 3: All terminal paths set isGameWinner somewhere along the path
-    // Note: We don't require isGameWinner to be set for draw/no-winner scenarios
+    // Check 3: At least one terminal path sets isGameWinner to true (winning scenario)
+    // Note: No-winner scenarios should explicitly set isGameWinner=false (not leave unset)
     const terminalPaths = graph.getTerminalPaths();
 
     if (terminalPaths.length === 0) {
@@ -1025,12 +1025,14 @@ export async function validateGameCompletion(
         }
       }
 
-      // Warn if no paths set isGameWinner (might be intentional for draw-only games)
+      // Check if at least one path sets isGameWinner to true (winning scenario)
+      // Note: Paths that set all players to false (no-winner scenarios) still count as setting the field
       if (!hasWinningPath) {
         errors.push(
-          'No path to "finished" sets players.*.isGameWinner. ' +
-          'If your game has winners, at least one ending path must set isGameWinner=true for winning players. ' +
-          'If this is a draw-only game (no winners), you can ignore this warning.'
+          'No path to "finished" sets players.*.isGameWinner to true. ' +
+          'At least one ending path must set isGameWinner=true for winning players. ' +
+          'For no-winner scenarios (abandoned/stalemate), explicitly set isGameWinner=false for all players. ' +
+          'Do not leave isGameWinner unset - validation requires explicit set operations.'
         );
       }
     }

src/ai/simulate/graphs/spec-processing-graph/nodes/extract-transitions/prompts.ts

@@ -62,7 +62,13 @@ Don't create phases that only exist to trigger one automatic transition. Merge t
 - ❌ Wrong: phase_a → [trivial transition] → phase_b → [does actual work] → phase_c
 - ✅ Right: phase_a → [does all work] → phase_c
 
-### 5. Precondition Hints (for executor synthesis)
+### 5. Game-Ending Transitions MUST Set Winner
+
+⚠️ **CRITICAL**: Every path to "finished" must explicitly set the game winner. Any transition that determines winners MUST include "set isGameWinner" guidance in its \`humanSummary\` or validation will fail.
+
+Example: "After round 3, determine winner by closest guess, set isGameWinner=true for winner and false for others, then end game"
+
+### 6. Precondition Hints (for executor synthesis)
 When writing \`explain\` text for preconditionHints, follow these rules so executor can synthesize valid JsonLogic:
 
 ✅ Use wildcard for player array checks: "players[*].actionRequired == false"