diff --git a/src/game/engine/scenes/tests/auto_play.gd b/src/game/engine/scenes/tests/auto_play.gd
index 22f355e9..281691c6 100644
--- a/src/game/engine/scenes/tests/auto_play.gd
+++ b/src/game/engine/scenes/tests/auto_play.gd
@@ -829,7 +829,7 @@ func _apply_difficulty_starting_bonuses() -> void:
 		return
 	var unit_manager: Node = get_node_or_null("/root/UnitManager")
 	for p: Variant in GameState.players:
-		if p is PlayerScript and not p.is_human:
+		if p is Player and not p.is_human:
 			if gold_bonus > 0:
 				p.gold += gold_bonus
 			if extra_units > 0 and unit_manager != null:
diff --git a/src/simulator/api-gdext/src/ai.rs b/src/simulator/api-gdext/src/ai.rs
index ea57649d..062f98dc 100644
--- a/src/simulator/api-gdext/src/ai.rs
+++ b/src/simulator/api-gdext/src/ai.rs
@@ -143,8 +143,9 @@ impl GdMcTreeController {
         };
 
         let processor = TurnProcessor::new(300);
-        let snapshot = McSnapshot::from_game_state(&state, &processor);
+        let mut snapshot = McSnapshot::from_game_state(&state, &processor);
         let pi = player_index.max(0) as usize;
+        snapshot.active_player = pi as u8;
         let base_seed = seed as u64;
         let depth = self.rollout_depth;
 
@@ -239,8 +240,9 @@ impl GdMcTreeController {
         };
 
         let processor = TurnProcessor::new(300);
-        let snapshot = McSnapshot::from_game_state(&state, &processor);
+        let mut snapshot = McSnapshot::from_game_state(&state, &processor);
         let pi = player_index.max(0) as usize;
+        snapshot.active_player = pi as u8;
         let base_seed = seed as u64;
         let depth = self.rollout_depth;
 
@@ -526,6 +528,7 @@ mod tests {
             ],
             config: LairCombatConfig::default(),
             victory_city_count: 30,
+            active_player: 0,
         }
     }
 
diff --git a/src/simulator/crates/mc-turn/src/snapshot.rs b/src/simulator/crates/mc-turn/src/snapshot.rs
index 5d326a14..c5ac8d05 100644
--- a/src/simulator/crates/mc-turn/src/snapshot.rs
+++ b/src/simulator/crates/mc-turn/src/snapshot.rs
@@ -191,6 +191,27 @@ impl TreeState for McSnapshot {
     fn is_terminal(&self) -> bool {
         self.is_terminal()
     }
+
+    /// Personality-weighted action prior for PUCT selection (p0-38).
+    ///
+    /// Maps `McAction` variants to the `active_player`'s `ScoringWeights`:
+    /// - `SpawnUnit` → `military_base` (aggressive clans prefer early armies)
+    /// - `FoundCity` → `expansion` (expansionist clans prefer new cities)
+    /// - `Idle` → 1.0 baseline (everyone considers doing nothing)
+    ///
+    /// Returns unnormalised weights — `Tree::best_puct_child` normalises via
+    /// the PUCT formula rather than requiring pre-normalised priors.
+    fn action_prior(&self, action: &McAction) -> f32 {
+        let Some(p) = self.players.get(self.active_player as usize) else {
+            return 1.0;
+        };
+        let w = &p.scoring_weights;
+        match action {
+            McAction::SpawnUnit => w.military_base.max(0.1),
+            McAction::FoundCity => w.expansion_base.max(0.1),
+            McAction::Idle => 1.0,
+        }
+    }
 }
 
 // ── Tests ────────────────────────────────────────────────────────────────────