fix(rules): correct P1 PF1e conformance bugs (area saves, concentration, prone, slots, helpless, nauseated)

tests/test_concentration.py

@@ -5,12 +5,15 @@ The concentration DC depends on the casting situation (CRB Table 9-1):
 - grappled or pinned:    DC = 10 + grappler's CMB + spell_level
 - casting defensively:   DC = 15 + 2 * spell_level
 
-The check roll = d20 + caster_level + casting ability mod (+4 Combat Casting),
-unchanged from the current logic.
+The check roll = d20 + caster level + the casting ability modifier used to
+determine bonus spells (Int/Wis/Cha) — NOT Constitution (PF1e conformance
+fix B2). Combat Casting's +4 applies only when casting defensively or while
+grappled — never for damage taken while casting.
 """
 
 from __future__ import annotations
 
+from pf1e_simulator.abilities import AbilitySpec
 from pf1e_simulator.combat import CombatantState, CombatEngine
 from pf1e_simulator.dice import parse_dice
 from pf1e_simulator.grid import Grid
@@ -32,6 +35,11 @@ def _combatant(
     level: int = 5,
     con: int = 12,
     cmb: int | None = None,
+    casting_ability: str = "wis",
+    int_score: int = 10,
+    wis_score: int = 10,
+    cha_score: int = 10,
+    combat_casting: bool = False,
 ) -> Combatant:
     attack = AttackSpec(
         id=f"{cid}-w",
@@ -40,6 +48,9 @@ def _combatant(
         attack_bonus=2,
         damage=[DamageComponent(formula=parse_dice("1d4"), types=["piercing"])],
     )
+    features = (
+        [AbilitySpec(name="Combat Casting", category="feat")] if combat_casting else []
+    )
     return Combatant(
         id=cid,
         name=cid,
@@ -49,9 +60,9 @@ def _combatant(
             str_score=10,
             dex_score=10,
             con_score=con,
-            int_score=10,
-            wis_score=10,
-            cha_score=10,
+            int_score=int_score,
+            wis_score=wis_score,
+            cha_score=cha_score,
         ),
         hp_max=30,
         ac=ACProfile(total=12, touch=12, flat_footed=10),
@@ -61,6 +72,8 @@ def _combatant(
         saves=Saves(fort=0, ref=0, will=0),
         attacks=[attack],
         cmb=cmb,
+        casting_ability=casting_ability,
+        features=features,
     )
 
 
@@ -113,3 +126,52 @@ class TestConcentrationDc:
         assert engine_pass._check_concentration(c, 1, damage_taken=4) is True
         engine_fail = _make_engine(caster, grappler, [9])[0]
         assert engine_fail._check_concentration(c, 1, damage_taken=4) is False
+
+
+class TestConcentrationUsesCastingAbilityNotCon:
+    """B2 (PF1e conformance): the check is d20 + caster level + the ability
+    modifier used for bonus spells (Int/Wis/Cha) — NOT Constitution."""
+
+    def test_high_con_low_casting_ability_fails_where_con_would_pass(self) -> None:
+        # CON 18 (+4) but casting ability INT 10 (+0): injured DC = 10+4+1 = 15.
+        # Correct roll: d20 6 + level 5 + int 0 = 11 < 15 -> FAIL.
+        # The old CON-based check would have given 6 + 5 + 4 = 15 -> pass.
+        caster = _combatant("caster", level=5, con=18, casting_ability="int")
+        grappler = _combatant("grappler")
+        engine, c, _ = _make_engine(caster, grappler, [6])
+        assert engine._check_concentration(c, 1, damage_taken=4) is False
+
+    def test_charisma_modifier_is_used_for_a_sorcerer(self) -> None:
+        # CHA 18 (+4), CON 6 (-2), casting ability cha: injured DC = 10+4+1 = 15.
+        # d20 6 + level 5 + cha 4 = 15 >= 15 -> PASS (CON would give 13 -> fail).
+        caster = _combatant("caster", level=5, con=6, cha_score=18, casting_ability="cha")
+        grappler = _combatant("grappler")
+        engine, c, _ = _make_engine(caster, grappler, [6])
+        assert engine._check_concentration(c, 1, damage_taken=4) is True
+
+
+class TestCombatCastingPlacement:
+    """B2 (PF1e conformance): Combat Casting's +4 applies only when casting
+    defensively or while grappled — never for damage taken while casting."""
+
+    def test_combat_casting_does_not_help_when_injured(self) -> None:
+        # Injured DC = 10+4+1 = 15. d20 6 + level 5 + wis 0 = 11 < 15 -> FAIL.
+        # The old blanket +4 would have made 15 -> pass.
+        caster = _combatant("caster", level=5, con=10, combat_casting=True)
+        grappler = _combatant("grappler")
+        engine, c, _ = _make_engine(caster, grappler, [6])
+        assert engine._check_concentration(c, 1, damage_taken=4) is False
+
+    def test_combat_casting_helps_when_casting_defensively(self) -> None:
+        # Defensive DC = 15 + 2*1 = 17. d20 8 + level 5 + wis 0 + 4 = 17 -> PASS.
+        caster = _combatant("caster", level=5, con=10, combat_casting=True)
+        grappler = _combatant("grappler")
+        engine, c, _ = _make_engine(caster, grappler, [8])
+        assert engine._check_concentration(c, 1, damage_taken=0) is True
+
+    def test_combat_casting_helps_while_grappled(self) -> None:
+        # Grappled DC = 10 + CMB 3 + level 1 = 14. d20 5 + 5 + 0 + 4 = 14 -> PASS.
+        caster = _combatant("caster", level=5, con=10, combat_casting=True)
+        grappler = _combatant("grappler", cmb=3)
+        engine, c, _ = _make_engine(caster, grappler, [5], grappled=True)
+        assert engine._check_concentration(c, 1, damage_taken=0) is True