fix(rules): summon duration scales with caster level (SRD summon-monster: 1 round/level (D)) - SummonEffect gains duration_rounds_per_level resolved at cast time, summon_monster_i/ii JSON updated

src/pf1e_simulator/combat.py

@@ -7220,6 +7220,15 @@ class CombatEngine:
         _spell_name: str,
     ) -> str:
         """Apply a summoning effect - create a summoned creature."""
+        # PF1e (SRD spells/summon-monster-1.md): "Duration 1 round/level (D)"
+        # - a per-level duration resolves against the caster's level at cast
+        # time, mirroring the ConditionEffect convention; a fixed duration is
+        # the pre-conformance fallback.
+        duration = effect.duration_rounds
+        if effect.duration_rounds_per_level > 0:
+            duration = max(
+                1, state.combatant.level * effect.duration_rounds_per_level
+            )
         # Load the summoned creature
         try:
             summoned_combatant = load_combatant(Path(effect.creature))
@@ -7256,7 +7265,7 @@ class CombatEngine:
         self._states.insert(caster_idx + 1, summoned_state)
 
         # Set expiration
-        summoned_state.summon_duration = effect.duration_rounds
+        summoned_state.summon_duration = duration
         summoned_state.summon_caster_id = state.combatant.id
         self._apply_simple_monster_death(summoned_state)
 
@@ -7265,7 +7274,7 @@ class CombatEngine:
 
         self._log(
             f"round {self._current_round} {state.combatant.id}: "
-            f"summon {summoned_combatant.id} at {spawn_pos} ({effect.duration_rounds}r)"
+            f"summon {summoned_combatant.id} at {spawn_pos} ({duration}r)"
         )
         return f"summoned {summoned_combatant.id}"
 

src/pf1e_simulator/spells.py

@@ -296,10 +296,17 @@ class SummonEffect:
     """Summoning spell effect.
 
     - creature: path to the creature JSON file (e.g., "data/monsters/celestial_wolf.json")
-    - duration_rounds: how long the summoned creature stays
+    - duration_rounds: fixed rounds the summoned creature stays, used when
+      ``duration_rounds_per_level`` is 0
+    - duration_rounds_per_level: PF1e "1 round/level" summoning duration
+      (SRD spells/summon-monster-1.md: "Duration 1 round/level (D)") - when
+      > 0 the rounds resolve at cast time as
+      ``max(1, caster_level * duration_rounds_per_level)``, mirroring
+      ``ConditionEffect``'s field of the same name.
     """
     creature: str
     duration_rounds: int
+    duration_rounds_per_level: int = 0
 
 
 SpellEffect = (
@@ -690,6 +697,9 @@ def _parse_summon_effect(effect: dict[str, Json]) -> SummonEffect:
     return SummonEffect(
         creature=_as_str(effect["creature"]),
         duration_rounds=_as_int(effect["duration_rounds"]),
+        duration_rounds_per_level=_as_int(
+            effect.get("duration_rounds_per_level", 0)
+        ),
     )