fix(rules): total defense denies attacks of opportunity (SRD Total Defense: allowance drops to 0 while the bonus is active)

src/pf1e_simulator/combat.py

@@ -744,9 +744,12 @@ class CombatantState:
     # granted by total defense (+4) and fighting defensively (+2), and the
     # fighting-defensively flag (-4 on attack and crit confirm). Both reset
     # at the start of the combatant's NEXT turn, so they last through the
-    # opponents' turns in between.
+    # opponents' turns in between. The total_defense flag additionally marks
+    # that the combatant is using total defense — PF1e (SRD "Total Defense"):
+    # "You can't make attacks of opportunity while using total defense."
     defensive_ac_bonus: int = 0
     fight_defensively: bool = False
+    total_defense: bool = False
     # Aid another & run (not in the frozen data model): aid bonuses granted to
     # this combatant by an ally's aid another — aid_attack_bonus is consumed by
     # its next attack roll, aid_ac_bonus applies against the next attack that
@@ -1776,6 +1779,7 @@ class CombatEngine:
             state.power_attack = False
             state.defensive_ac_bonus = 0
             state.fight_defensively = False
+            state.total_defense = False
             state.aid_attack_bonus = 0
             state.aid_ac_bonus = 0
             state.running = False
@@ -2693,7 +2697,12 @@ class CombatEngine:
 
         Base is 1. Combat Reflexes adds the DEX modifier on top (clamped to >= 1
         so a non-positive DEX mod never reduces the normal single AoO).
+        PF1e (SRD "Total Defense"): "You can't make attacks of opportunity
+        while using total defense" — the allowance drops to 0 while the
+        total-defense bonus is active (until the start of the next turn).
         """
+        if state.total_defense:
+            return 0
         if not self._has_feat(state, "Combat Reflexes"):
             return 1
         return max(1, 1 + ((state.combatant.abilities.dex_score - 10) // 2))
@@ -4089,7 +4098,11 @@ class CombatEngine:
     def _execute_total_defense(self, state: CombatantState) -> ActionResult:
         """Execute the total defense action (PF1e): standard action granting a
         +4 dodge bonus to AC until the start of the combatant's next turn.
+        PF1e (SRD "Total Defense"): "You can't make attacks of opportunity
+        while using total defense" — the flag drops the AoO allowance to 0
+        (see ``_aoo_allowance``).
         """
+        state.total_defense = True
         state.defensive_ac_bonus += _TOTAL_DEFENSE_AC_BONUS
         self._log(
             f"round {self._current_round} {state.combatant.id}: "