diff --git a/README.md b/README.md
index ac8bf99..84eaf35 100644
--- a/README.md
+++ b/README.md
@@ -350,8 +350,12 @@ Règles modélisées :
 - Se jeter à terre (`Action(kind="drop_prone")`, action libre) : le combattant
   ajoute `prone` à la liste `conditions` **sans durée**, donc la condition
   persiste jusqu'à `stand_up` (contrairement à trip/overrun qui posent
-  `active_conditions` avec 1 round). Les modificateurs de `prone` (−4 CA, −4 aux
-  attaques à distance) s'appliquent immédiatement. Si la condition est déjà
+  `active_conditions` avec 1 round). Les modificateurs de `prone` s'appliquent
+  immédiatement : l'attaquant à plat ventre subit −4 à ses attaques (de mêlée
+  selon le CRB ; les armes à distance sont traitées comme des arbalètes —
+  utilisables à −4, simplification documentée), la cible à plat ventre subit
+  −4 CA contre les attaques de mêlée et gagne +4 CA contre les attaques à
+  distance. Si la condition est déjà
   présente, l'action est rejetée (`already_prone`). Le kind ne requiert pas de
   cible. `default_policy` ne la choisit pas (disponible via une politique
   personnalisée).
@@ -555,15 +559,19 @@ Règles modélisées :
   condition inconnue ou non supportée reste exclue (False).
 - Incantation : chaque `CombatantState` porte `spell_slots_left` (initialisé depuis
   le champ `spell_slots` du JSON, ex. `{"1": 4, ...}`) ; `_cast_spell` dépense
-  l'emplacement du niveau concerné (`spend_spell_slot`). Le DD vaut `10 + niveau du
+  l'emplacement du niveau concerné (`spend_spell_slot`) — **sans emplacement
+  disponible, l'incantation est refusée** (journalisée `NO SPELL SLOT`, aucun
+  jet consommé) ; les cantrips (niveau 0) s'incantent librement. Le DD vaut `10 + niveau du
   sort + mod de la caractéristique d'incantation` (`casting_ability`), la sauvegarde
   est résolue par `resolve_save`, et la RD ne réduit pas les dégâts des sorts
   (`test_dr_does_not_reduce_spell_damage`). Incanter dans une
   case menacée provoque des AoO ; tout dégât subi pendant l'incantation impose un
   jet de concentration dont le DD dépend de la situation (`_concentration_dc`) :
   `10 + dégâts + niveau` si blessé, `10 + CMB de l'adversaire + niveau` si agrippé,
-  sinon `15 + 2×niveau` (incantation défensive), jet = d20 + niveau + mod de CON
-  (+4 avec le don Combat Casting). Un sort ciblé avec sauvegarde fait pleins dégâts
+  sinon `15 + 2×niveau` (incantation défensive), jet = d20 + niveau + mod de
+  la caractéristique d'incantation (Int/Wis/Cha — jamais Constitution, CRB) ;
+  le don Combat Casting n'accorde son +4 qu'en incantation défensive ou quand
+  on est agrippé, jamais pour les dégâts subis pendant l'incantation. Un sort ciblé avec sauvegarde fait pleins dégâts
   sur un échec et **aucun dégât sur un succès** (la sauvegarde annule) ; le
   demi-dégât sur sauvegarde réussie ne s'applique que là où l'effet le déclare
   (`half_on_save: true` pour les rayons/lignes/cônes, `AreaEffect.save_for_half`
@@ -609,9 +617,15 @@ Règles modélisées :
   de Dextérité à la CA** (même chemin `denies_dex_to_ac` que flat-footed/course).
   L'invisibilité est symétrique : subi comme cible, la condition accorde le
   concealment total de 50 % ci-dessus.
-- Cible inerme (helpless, V5a) : les attaques de **mêlée** contre une cible
-  `helpless` gagnent **+4 au jet d'attaque et à la confirmation** (aucun bonus à
-  distance) ; `helpless` porte `denies_dex_to_ac` (CA flat-footed) + `cant_act`.
+- Cible inerme (helpless, V5a + conformance P1) : sont traitées comme
+  **inertes** les conditions `helpless`, `paralyzed`, `asleep` et
+  `unconscious` (CRB : inerme = paralysé, immobilisé, ligoté, endormi,
+  inconscient — `stunned` **ne** rend **pas** inerme). Les attaques de
+  **mêlée** contre une cible inerme gagnent **+4 au jet d'attaque et à la
+  confirmation** (aucun bonus à distance) ; la cible a une **Dextérité
+  effective de 0** : son modificateur de Dextérité est entièrement remplacé
+  par la pénalité Dex 0 (−5), en plus de la perte du bonus de Dextérité
+  (CA flat-footed via `denies_dex_to_ac`).
   Simplification documentée : l'attaque sournoise automatique du roublard sur
   cible inerme n'est pas modélisée (la cible, privée de Dextérité, la déclenche
   déjà via le chemin `denies_dex_to_ac`).
@@ -639,15 +653,22 @@ Règles modélisées :
 - Conditions effectives : 28 conditions prédéfinies (`conditions.py`). Leurs drapeaux
   comportementaux sont appliqués par le moteur : `cant_act` (étourdi, paralysé, dazed,
   endormi, inerme, fasciné) annule le tour ; `cant_attack` (nauséeux) n'autorise qu'une unique action
-  simple et bloque toute attaque / manœuvre ; `staggered` restreint à une action
+  de mouvement (`move`, `5foot_step`, `stand_up`, `drop_prone`) et bloque toute
+  attaque, manœuvre **et incantation** (CRB : un nauséeux ne peut ni attaquer,
+  ni incanter, ni se concentrer) ; `staggered` restreint à une action
   simple (pas d'attaque à outrance) ; `cant_move` bloque le déplacement ;
-  `denies_dex_to_ac` (à plat ventre, paralysé…) fait perdre le bonus de Dextérité à
+  `denies_dex_to_ac` (flat-footed, paralysé, aveuglé…) fait perdre le bonus de Dextérité à
   la CA (CA flat-footed) ; `miss_chance` (flou 20 %, déplacement 50 %, invisible
   50 %) impose la
-  chance de rater du concealment. À plat ventre : −4 CA et −4 aux attaques à distance.
+  chance de rater du concealment. À plat ventre : l'attaquant à plat ventre
+  subit −4 à ses attaques (mêlée selon le CRB ; distance traitée arbalète à
+  −4, simplification documentée) ; la cible à plat ventre subit −4 CA contre
+  la mêlée et gagne +4 CA contre la distance (le CRB inverse du « −4 CA
+  contre tout » précédemment modélisé).
   Agrippé : −4 Dextérité, −2 attaque/CA/Réflexes, sans déplacement ni AoO.
-  Inerme (`helpless`) : ne peut pas agir, perd sa Dextérité à la CA, +4 en mêlée
-  contre lui (voir « Cible inerme »). Fasciné (`fascinated`) : ne peut pas agir.
+  Inerme (`helpless`, `paralyzed`, `asleep`, `unconscious`) : ne peut pas agir,
+  Dextérité effective 0 (−5 CA en plus de la perte du bonus), +4 en mêlée
+  contre lui (voir « Cible inerme ») ; `stunned` ne rend pas inerte. Fasciné (`fascinated`) : ne peut pas agir.
   Invisible (`invisible`) : concealment total subi +2 attaquant / perte de Dex
   de la cible (voir « Attaquant invisible »).
   Saignement (`bleeding`, V5b) : une créature qui saigne subit `bleed_damage`
@@ -690,8 +711,12 @@ Règles modélisées :
 - Sortilèges du sorcier (witch hex) : le DD vaut `10 + niveau//2 + mod d'Intelligence`
   (evil_eye, slumber, cackle) ; `cackle` prolonge d'un round les sortilèges déjà
   actifs, sur une liste instantanée pour ne pas s'étendre à l'infini. Les sorts à
-  zone (AoE) utilisent le DD d'incantation du jeteur et, sur une sauvegarde réussie,
-  ne font que la moitié des dégâts.
+  zone (AoE) utilisent le DD d'incantation du jeteur et chaque créature de la
+  zone effectue la sauvegarde listée par le sort (Volonté / Réflexes /
+  Constitution — le sort primaire réutilise son jet déjà effectué) ; un succès
+  annule ou divise par deux selon ce que l'effet déclare (`save_negates` /
+  `half_on_save` / `AreaEffect.save_for_half`) — les zones « sauvegarde
+  annule » (Sleep, Color Spray, Web) sauvent donc aussi.
 - Dons : les 8 PJ portent 55 noms de dons uniques ; le chargeur résout chacun d'eux
   soit vers un effet réel (Power Attack actif, Weapon Focus ciblé par arme, Toughness
   lié au niveau, dons passifs via `_stat_modifiers`), soit vers un « no-op » tracé en
diff --git a/src/pf1e_simulator/combat.py b/src/pf1e_simulator/combat.py
index f6a1d0e..dcc55ff 100644
--- a/src/pf1e_simulator/combat.py
+++ b/src/pf1e_simulator/combat.py
@@ -101,6 +101,7 @@ from pf1e_simulator.spells import (
     ConditionEffect,
     DamageEffect,
     HealEffect,
+    SaveType,
     SpellEffect,
     SummonEffect,
     save_descriptors_for_effects,
@@ -166,6 +167,13 @@ _CONFUSED_BABBLE_MAX = 50
 _CONFUSED_SELF_DAMAGE_MAX = 75
 _INVISIBLE_ATTACK_BONUS = 2  # PF1e: +2 attack rolls for an invisible attacker
 _HELPLESS_MELEE_BONUS = 4  # PF1e: +4 melee attack rolls (and crit confirms) vs helpless
+# PF1e: a helpless creature (paralyzed, held, bound, sleeping, unconscious —
+# stunned is NOT helpless) has an effective Dexterity score of 0, i.e. a -5
+# modifier for a Medium creature (CRB, Helpless condition).
+_DEX_ZERO_MOD = -5
+_HELPLESS_CONDITION_NAMES: frozenset[str] = frozenset(
+    {"helpless", "paralyzed", "asleep", "unconscious"}
+)
 _AID_ANOTHER_DC = 10  # PF1e: aid another is an attack roll against AC 10
 _AID_ANOTHER_BONUS = 2  # PF1e: a successful aid grants +2 (next attack or AC)
 _RUN_SPEED_FACTOR = 4  # PF1e: running is a full-round action at 4x speed
@@ -1341,6 +1349,16 @@ class CombatEngine:
             or any(cond.name == name for cond in state.conditions)
         )
 
+    def _is_helpless(self, state: CombatantState) -> bool:
+        """PF1e (CRB): helpless = paralyzed, held, bound, sleeping, unconscious.
+
+        Stunned is NOT helpless. A helpless creature has effective Dexterity 0
+        and melee attackers gain +4 (resolve_attack)."""
+        return any(
+            self._has_condition_named(state, name)
+            for name in _HELPLESS_CONDITION_NAMES
+        )
+
     def _modifier_condition_holds(
         self,
         _state: CombatantState,
@@ -1805,11 +1823,9 @@ class CombatEngine:
                 if m.target == target
                 and (m.weapon_filter is None or m.weapon_filter == weapon_name)
             )
-        if target == "ac":
-            if self._has_condition_named(state, "prone"):
-                mods.append(StatModifier(target="ac", value=-4))
-            if self._has_condition_named(state, "paralyzed"):
-                mods.append(StatModifier(target="ac", value=-4))
+        # PF1e: prone and helpless (paralyzed/asleep/unconscious) AC
+        # adjustments depend on the weapon kind and are applied in
+        # resolve_attack, where it is known — not unconditionally here.
         return [
             m
             for m in mods
@@ -1901,6 +1917,29 @@ class CombatEngine:
             return 0
         return max(1, attacker.combatant.bab // 4 + 1)
 
+    def _attack_ac_mods(
+        self, target: CombatantState, weapon: AttackSpec
+    ) -> list[StatModifier]:
+        """AC modifiers for one attack — the weapon-kind-dependent ones included.
+
+        PF1e (CRB): a prone defender takes -4 AC against melee attacks but
+        gains +4 AC against ranged attacks; a helpless defender (paralyzed,
+        asleep, unconscious, helpless) has an effective Dexterity score of 0,
+        so its whole Dex modifier gives way to the Dex-0 penalty (-5) —
+        flat-footed AC already drops a positive Dex bonus, a native Dex
+        penalty must still be replaced."""
+        mods = self._stat_modifiers(target, "ac")
+        if self._has_condition_named(target, "prone"):
+            mods.append(
+                StatModifier(
+                    target="ac", value=4 if self._is_ranged_attack(weapon) else -4
+                )
+            )
+        if self._is_helpless(target):
+            dex_penalty = min(0, target.combatant.abilities.dex_mod)
+            mods.append(StatModifier(target="ac", value=_DEX_ZERO_MOD - dex_penalty))
+        return mods
+
     def resolve_attack(
         self,
         attacker: CombatantState,
@@ -1929,14 +1968,21 @@ class CombatEngine:
         atk_mods = self._stat_modifiers(
             attacker, "attack", weapon_name=weapon.name, weapon=weapon, dist_ft=dist_ft
         )
-        if self._is_ranged_attack(weapon) and self._has_condition_named(attacker, "prone"):
+        # PF1e (CRB): a prone attacker takes -4 on melee attack rolls. Ranged
+        # weapons cannot be used while prone at all, EXCEPT crossbows, which
+        # stay usable at -4. The model cannot tell a crossbow from a bow, so
+        # every ranged weapon is treated as the crossbow-exempt case: usable,
+        # but at -4 (documented simplification).
+        if self._has_condition_named(attacker, "prone"):
             atk_mods.append(StatModifier(target="attack", value=-4))
         # PF1e: an invisible attacker strikes from an unknown direction (+2 on
         # attack and crit confirmation, target loses its Dex bonus to AC).
         if self._has_condition_named(attacker, "invisible"):
             atk_mods.append(StatModifier(target="attack", value=_INVISIBLE_ATTACK_BONUS))
-        # PF1e: melee attacks against a helpless target gain +4 (ranged none).
-        if weapon.kind == "melee" and self._has_condition_named(target, "helpless"):
+        # PF1e (CRB): melee attacks against a helpless target gain +4; the
+        # helpless state includes paralyzed, asleep and unconscious (stunned
+        # is NOT helpless). Ranged attacks gain no bonus.
+        if weapon.kind == "melee" and self._is_helpless(target):
             atk_mods.append(StatModifier(target="attack", value=_HELPLESS_MELEE_BONUS))
         attack_mod = resolve_modifiers(atk_mods)
         pa_amt = self._power_attack_amt(attacker) if weapon.kind == "melee" else 0
@@ -1976,7 +2022,8 @@ class CombatEngine:
                 base_ac = target.combatant.ac.touch
         else:
             base_ac = full_ac_base
-        ac = base_ac + resolve_modifiers(self._stat_modifiers(target, "ac"))
+        ac_mods = self._attack_ac_mods(target, weapon)
+        ac = base_ac + resolve_modifiers(ac_mods)
         ac += target.defensive_ac_bonus
         ac += target.aid_ac_bonus
         occupied = frozenset(
@@ -2609,17 +2656,19 @@ class CombatEngine:
     ) -> bool:
         """Concentration check: DC depends on situation.
 
-        Roll = d20 + caster_level + casting ability mod (+4 Combat Casting).
+        PF1e (CRB): the check is d20 + caster level + the ability modifier
+        used to determine bonus spells (Int/Wis/Cha) — NOT Constitution.
+        Combat Casting's +4 applies only when casting defensively or while
+        grappled/pinned, never for damage taken while casting.
         """
         dc = self._concentration_dc(caster, spell_level, damage_taken)
-        has_combat_casting = any(f.name == "Combat Casting" for f in caster.combatant.features)
-        bonus = 4 if has_combat_casting else 0
+        injured_while_casting = damage_taken > 0 and caster.grappled_with is None
+        has_combat_casting = self._has_feat(caster, "Combat Casting")
+        bonus = 0 if injured_while_casting else (4 if has_combat_casting else 0)
         roll = self._rng.d20()
-        # Use caster level + ability mod for concentration check
-        caster_level = caster.combatant.level
-        # For concentration, the check is d20 + caster_level + ability_mod (usually Con)
-        con_mod = (caster.combatant.abilities.con_score - 10) // 2
-        total = roll + caster_level + con_mod + bonus
+        total = (
+            roll + caster.combatant.level + self._casting_ability_mod(caster) + bonus
+        )
         return total >= dc
     def can_step5_to_attack(self, state: CombatantState, target: CombatantState) -> bool:
         """True if a 5-foot step toward ``target`` would put ``state`` in weapon range."""
@@ -3334,6 +3383,14 @@ class CombatEngine:
         """Cast the carried spell; an explicit ``target_pos`` (U7b) is
         validated first — an off-map point or one without line of effect
         from the caster is rejected without casting."""
+        if self.has_condition_flag(state, "cant_attack"):
+            # PF1e (CRB): a nauseated creature cannot cast spells or
+            # concentrate; the cant_attack flag blocks the cast entirely.
+            self._log(
+                f"round {self._current_round} {state.combatant.id}: "
+                f"cast_spell rejected (cannot attack)"
+            )
+            return None
         if target_pos is not None:
             rejection = self._point_target_rejection(state, target_pos)
             if rejection is not None:
@@ -4142,12 +4199,15 @@ class CombatEngine:
             return
         self._charge(state, target, result.weapon)
 
-    def _spell_dc(self, caster: CombatantState, spell: SpellSpec) -> int:
-        """Spell save DC: 10 + spell level + casting ability modifier."""
+    def _casting_ability_mod(self, caster: CombatantState) -> int:
+        """Modifier of the casting ability (the one used for bonus spells)."""
         ability_name = caster.combatant.casting_ability.lower()
         ability_score = getattr(caster.combatant.abilities, f"{ability_name}_score")
-        ability_mod = (ability_score - 10) // 2
-        return 10 + spell.level + ability_mod
+        return (ability_score - 10) // 2
+
+    def _spell_dc(self, caster: CombatantState, spell: SpellSpec) -> int:
+        """Spell save DC: 10 + spell level + casting ability modifier."""
+        return 10 + spell.level + self._casting_ability_mod(caster)
 
     def _spell_snapshot(self, state: CombatantState, spell_name: str) -> dict[str, object]:
         """One per-spell dict for the Observation, enriched from the registry."""
@@ -4208,10 +4268,18 @@ class CombatEngine:
             caster, target, spell, spell_name, center_pos, has_area=has_area
         ):
             return
+        # PF1e (CRB): a caster cannot cast without an available slot of the
+        # spell's level; cantrips (level 0) are cast freely. The slot is spent
+        # up-front — a later failed concentration check still burns it.
+        if spell.level > 0 and not caster.spend_spell_slot(spell.level):
+            self._log(
+                f"round {self._current_round} {caster.combatant.id}: "
+                f"cast {spell_name} -> NO SPELL SLOT (level {spell.level})"
+            )
+            return
         # Check for AoO from casting in threatened square (before resolving spell)
         if self._check_casting_aoo(caster, spell.level):
             return
-        caster.spend_spell_slot(spell.level)
         if (
             target is not None
             and not has_area
@@ -4311,7 +4379,7 @@ class CombatEngine:
             caster=caster, spell_name=spell.name,
             empower="Empower Spell" in metamagic_feats,
             maximize="Maximize Spell" in metamagic_feats,
-            dc=dc, center_pos=center_pos,
+            dc=dc, center_pos=center_pos, save_type=spell.save,
         )
         save_str = _save_label(save_result)
         if target is None and center_pos is not None:
@@ -4349,7 +4417,7 @@ class CombatEngine:
         """Legacy wrapper for compatibility."""
         return self._apply_spell_effects_from_list(
             spell.effects, target, save_result, caster_live, target_live,
-            caster=target, spell_name=spell.name
+            caster=target, spell_name=spell.name, save_type=spell.save
         )
 
     def _apply_spell_effects_from_list(
@@ -4366,6 +4434,7 @@ class CombatEngine:
         maximize: bool = False,
         dc: int = 15,
         center_pos: tuple[int, int] | None = None,
+        save_type: SaveType = "none",
     ) -> list[str]:
         saved = save_result is not None and save_result.success
         return [
@@ -4373,7 +4442,7 @@ class CombatEngine:
                 effect, target, caster_live, target_live,
                 caster=caster, spell_name=spell_name,
                 empower=empower, maximize=maximize, saved=saved,
-                dc=dc, center_pos=center_pos,
+                dc=dc, center_pos=center_pos, save_type=save_type,
             )
             for effect in effects
         ]
@@ -4392,13 +4461,14 @@ class CombatEngine:
         saved: bool,
         dc: int = 15,
         center_pos: tuple[int, int] | None = None,
+        save_type: SaveType = "none",
     ) -> str:
         if isinstance(effect, AreaEffect):
             return self._apply_area_effect(
                 effect, target, caster_live, target_live,
                 caster=caster, spell_name=spell_name, saved=saved,
                 empower=empower, maximize=maximize, dc=dc,
-                center_pos=center_pos,
+                center_pos=center_pos, save_type=save_type,
             )
         if isinstance(effect, SummonEffect):
             return self._apply_summon_effect(effect, caster, caster_live, spell_name)
@@ -4535,6 +4605,7 @@ class CombatEngine:
         maximize: bool = False,
         dc: int = 15,
         center_pos: tuple[int, int] | None = None,
+        save_type: SaveType = "none",
     ) -> str:
         """Apply an area effect to all creatures within radius.
 
@@ -4558,7 +4629,8 @@ class CombatEngine:
             if not self._check_spell_resistance(caster, affected_state):
                 continue
             creature_saved = self._area_save(
-                affected_state, target, effect, saved=saved, dc=dc
+                affected_state, target, effect, saved=saved, dc=dc,
+                save_type=save_type,
             )
             for sub_effect in effect.effects:
                 target_live = self._stats[affected_state.combatant.id]
@@ -4603,19 +4675,27 @@ class CombatEngine:
         *,
         saved: bool,
         dc: int = 15,
+        save_type: SaveType = "none",
     ) -> bool:
         """Save result for one creature in an area effect.
 
+        PF1e (CRB): every creature in the area rolls the save the SPELL lists
+        (Will / Fortitude / Reflex) — "save negates" and "save for half" both
+        grant it; whether a success negates or halves is decided per sub-effect
+        (``save_negates`` / ``half_on_save``), never by skipping the roll.
         The resolved primary target re-uses its already-rolled save; every
         other creature in the area — and every creature of a point-targeted
         burst (no primary target, U7b) — rolls its own.
         """
-        if not effect.save_for_half:
+        if save_type == "none":
             return False
         if affected_state is target:
             return saved
         save_result = self.resolve_save(
-            affected_state, "ref", dc, save_descriptors=save_descriptors_for_effects(effect.effects)
+            affected_state,
+            save_type,
+            dc,
+            save_descriptors=save_descriptors_for_effects(effect.effects),
         )
         return save_result.success
 
@@ -5277,10 +5357,12 @@ def _choose_spell_action(
 
 
 _FULL_ROUND_KINDS: frozenset[str] = frozenset({"full_attack", "charge", "withdraw", "full_round"})
-_STANDARD_KINDS: frozenset[str] = frozenset({
-    "attack", "cast_spell", "maneuver", "hex", "deed", "spell_combat", "channel_energy",
-})
 _SWIFT_BONUS_KINDS: frozenset[str] = frozenset({"deed", "inspire_courage", "swift"})
+# PF1e (CRB): a nauseated creature can take only a single move action per
+# turn — no standard, no full-round, no attacks, no spellcasting.
+_NAUSEA_MOVE_KINDS: frozenset[str] = frozenset(
+    {"move", "5foot_step", "stand_up", "drop_prone"}
+)
 
 
 def _without_swift_bonus(actions: tuple[Action, ...]) -> tuple[Action, ...]:
@@ -5316,9 +5398,13 @@ def _staggered_filter(actions: tuple[Action, ...]) -> tuple[Action, ...]:
 
 
 def _nauseated_filter(actions: tuple[Action, ...]) -> tuple[Action, ...]:
-    """Nauseated: single standard action only."""
+    """PF1e (CRB) nauseated: a single move action per turn, nothing else.
+
+    The sequence collapses to its first move-like action; standard actions
+    (attack, cast_spell, maneuver, ...) and full-round actions are dropped.
+    """
     for action in actions:
-        if action.kind in _STANDARD_KINDS:
+        if action.kind in _NAUSEA_MOVE_KINDS:
             return (action,)
     return ()
 
diff --git a/src/pf1e_simulator/conditions.py b/src/pf1e_simulator/conditions.py
index d7b54e1..9a95d90 100644
--- a/src/pf1e_simulator/conditions.py
+++ b/src/pf1e_simulator/conditions.py
@@ -205,12 +205,11 @@ DAZED = Condition(
     cant_act=True,
 )
 
-# Asleep/Unconscious: helpless, can't act, -4 AC vs melee, no Dex to AC (CRB)
+# Asleep/Unconscious: helpless (CRB) — can't act, no Dex to AC. The old flat
+# -4 AC approximation is superseded by the engine's Dex-0 (-5) adjustment for
+# helpless targets, applied in resolve_attack (CombatEngine._is_helpless).
 ASLEEP = Condition(
     name="asleep",
-    modifiers=(
-        StatModifier(target="ac", value=-4),
-    ),
     denies_dex_to_ac=True,
     cant_act=True,
     cant_move=True,
@@ -218,7 +217,10 @@ ASLEEP = Condition(
 
 
 # Helpless: helpless for all intents, treated as Dex 0 (loses Dex to AC),
-# can't act; melee attackers gain +4 (engine logic in resolve_attack) (CRB)
+# can't act; melee attackers gain +4 (engine logic in resolve_attack). The
+# engine also treats paralyzed/asleep/unconscious as helpless (CRB: "helpless"
+# = paralyzed, held, bound, sleeping, unconscious; stunned is NOT helpless) —
+# see CombatEngine._is_helpless (CRB)
 HELPLESS = Condition(
     name="helpless",
     denies_dex_to_ac=True,
diff --git a/tests/test_action_feedback.py b/tests/test_action_feedback.py
index cc7d58a..852d80d 100644
--- a/tests/test_action_feedback.py
+++ b/tests/test_action_feedback.py
@@ -160,8 +160,8 @@ def test_staggered_full_attack_downgrade_recorded_with_ok_attack() -> None:
 
 
 def test_nauseated_full_attack_downgrade_recorded() -> None:
-    # Nauseated: full_attack is not a standard action → the filter empties the
-    # sequence; only the synthetic downgrade result remains.
+    # Nauseated (B6): only move-like actions survive the filter — full_attack
+    # is dropped; only the synthetic downgrade result remains.
     eng = _engine(
         [10, 5],
         policy=_fixed_policy(Action(kind="full_attack", target_id="foe")),
diff --git a/tests/test_concentration.py b/tests/test_concentration.py
index 5138dbc..37c0dcb 100644
--- a/tests/test_concentration.py
+++ b/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
diff --git a/tests/test_conditional_modifiers.py b/tests/test_conditional_modifiers.py
index 3f795be..a83252e 100644
--- a/tests/test_conditional_modifiers.py
+++ b/tests/test_conditional_modifiers.py
@@ -380,6 +380,7 @@ def _make_caster(cid: str = "caster") -> Combatant:
         saves=Saves(fort=3, ref=4, will=4),
         attacks=[attack],
         casting_ability="int",
+        spell_slots={0: 99, 1: 99, 2: 99, 3: 99},
     )
 
 
diff --git a/tests/test_conditions_blinded_invisible.py b/tests/test_conditions_blinded_invisible.py
index f9a0543..6c29f8b 100644
--- a/tests/test_conditions_blinded_invisible.py
+++ b/tests/test_conditions_blinded_invisible.py
@@ -164,9 +164,10 @@ def test_melee_vs_helpless_target_gains_plus4() -> None:
     a, t = eng._states
     _add_condition(t, "helpless")
     result = eng.resolve_attack(a, t, a.combatant.attacks[0])
-    # roll 10 + bonus 5 + 4 (helpless melee) = 19; AC = flat-footed 10 (Dex denied).
+    # roll 10 + bonus 5 + 4 (helpless melee) = 19; AC = flat-footed 10 minus
+    # the Dex-0 penalty (helpless target has effective Dexterity 0: -5).
     assert result.total == 19
-    assert result.ac == 10
+    assert result.ac == 5
     assert result.hit is True
 
 
@@ -180,7 +181,7 @@ def test_melee_vs_helpless_plus4_applies_to_crit_confirmation() -> None:
     a, t = eng._states
     _add_condition(t, "helpless")
     result = eng.resolve_attack(a, t, a.combatant.attacks[0])
-    # Confirm 10 + 5 + 4 = 19 >= 10 -> crit.
+    # Confirm 10 + 5 + 4 = 19 >= 5 (flat-footed 10 - 5 Dex-0) -> crit.
     assert result.crit is True
     assert result.damage == 8
 
diff --git a/tests/test_conditions_effects.py b/tests/test_conditions_effects.py
index c69a16f..61a6cf8 100644
--- a/tests/test_conditions_effects.py
+++ b/tests/test_conditions_effects.py
@@ -189,13 +189,14 @@ class TestStaggeredActionEconomy:
         assert result is False
 
 
-# ── Test 4: nauseated → single standard action only ───────────────────────────
+# ── Test 4: nauseated → single move action only ───────────────────────────────
 
 
 class TestNauseatedActionEconomy:
     """Given: a nauseated combatant
     When: _take_turn is called
-    Then: they can only take standard actions (no full attack, no charge, no move)."""
+    Then: they can only take a single move action (no standard, no attack,
+    no spellcasting — CRB nauseated)."""
 
     def test_nauseated_no_attack_and_no_full_round(self) -> None:
         hero = _make_hero(bab=6)
@@ -241,7 +242,7 @@ class TestParalyzedNoActions:
         assert found_wait, "paralyzed combatant should log 'wait (cannot act)'"
 
     def test_paralyzed_defender_helpless_ac(self) -> None:
-        """Paralyzed target: denies_dex_to_ac=True (flat-footed) + -4 AC (helpless)."""
+        """Paralyzed is helpless: denies_dex_to_ac (flat-footed) + Dex 0 (-5)."""
         hero = _make_hero()
         foe = _make_foe()
         engine, h, f = _make_engine(hero, foe, [10, 4])
@@ -249,8 +250,10 @@ class TestParalyzedNoActions:
             ActiveCondition(condition=PARALYZED, rounds_left=5, source="test")
         )
         result = engine.resolve_attack(h, f, hero.attacks[0])
-        # Paralyzed: denies_dex_to_ac → flat_footed AC 13; plus -4 helpless → 9
-        assert result.ac == 9
+        # Paralyzed: denies_dex_to_ac → flat_footed AC 13; helpless Dex 0 → -5;
+        # melee attacker also gains the +4 helpless bonus (roll 10 + 5 + 4 = 19).
+        assert result.ac == 8
+        assert result.total == 19
 
 
 # ── Test 6: StatModifier condition filtering ──────────────────────────────────
diff --git a/tests/test_conformance_p1.py b/tests/test_conformance_p1.py
new file mode 100644
index 0000000..70a24a8
--- /dev/null
+++ b/tests/test_conformance_p1.py
@@ -0,0 +1,438 @@
+"""P1 PF1e conformance fixes (Oracle-adjudicated audit).
+
+Six genuine RAW deviations, one section per bug:
+
+B1  Area saves: every creature in an area rolls the save the SPELL lists
+    (Will / Fortitude / Reflex); "save negates" areas save, and secondary
+    creatures are not hardcoded to Reflex.
+B2  Concentration: d20 + caster level + the casting ability modifier
+    (Int/Wis/Cha), never Constitution; Combat Casting's +4 only applies
+    when casting defensively or while grappled.
+B3  Prone: the prone attacker takes -4 on melee attacks (ranged treated as
+    crossbow-exempt at -4); the prone defender takes -4 AC vs melee and
+    gains +4 AC vs ranged.
+B4  Spell slots: casting without an available slot is refused; cantrips
+    (level 0) cast freely.
+B5  Helpless: paralyzed / asleep / unconscious (and helpless) are helpless —
+    melee attackers gain +4 and the target has effective Dexterity 0 (-5);
+    stunned is NOT helpless.
+B6  Nauseated: only a single move action per turn — no standard actions, no
+    attacks, no spellcasting, no concentration.
+
+B2 is covered in tests/test_concentration.py; B1's per-spell cases in
+tests/test_spells.py (TestAreaSavesPerSpellSaveType). This file adds the
+cross-cutting conformance locks.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+
+from pf1e_simulator.combat import (
+    Action,
+    ActionResult,
+    CombatantState,
+    CombatEngine,
+    _nauseated_filter,
+)
+from pf1e_simulator.conditions import (
+    ASLEEP,
+    CONDITIONS_BY_NAME,
+    PARALYZED,
+    Condition,
+)
+from pf1e_simulator.dice import parse_dice
+from pf1e_simulator.effects import ActiveCondition
+from pf1e_simulator.grid import Grid
+from pf1e_simulator.map import MapSpec, TerrainType
+from pf1e_simulator.models import (
+    AbilityScores,
+    ACProfile,
+    AttackSpec,
+    Combatant,
+    DamageComponent,
+    Saves,
+)
+from pf1e_simulator.rng import ScriptedRng
+from pf1e_simulator.spells import (
+    AreaEffect,
+    ConditionEffect,
+    DamageEffect,
+    SpellSpec,
+)
+
+PolicyFn = Callable[[CombatEngine, CombatantState], tuple[Action, ...]]
+
+
+def _melee(cid: str) -> AttackSpec:
+    return AttackSpec(
+        id=f"{cid}-sword",
+        name="short sword",
+        kind="melee",
+        attack_bonus=5,
+        damage=[DamageComponent(formula=parse_dice("1d6"), types=["slashing"])],
+    )
+
+
+def _bow(cid: str) -> AttackSpec:
+    return AttackSpec(
+        id=f"{cid}-bow",
+        name="short bow",
+        kind="ranged",
+        attack_bonus=5,
+        damage=[DamageComponent(formula=parse_dice("1d6"), types=["piercing"])],
+        range_increment_ft=60,
+    )
+
+
+def _combatant(
+    cid: str,
+    *,
+    level: int = 1,
+    hp: int = 100,
+    ac: int = 15,
+    dex: int = 10,
+    attacks: tuple[AttackSpec, ...] = (),
+    spells: tuple[str, ...] = (),
+    spell_slots: dict[int, int] | None = None,
+) -> Combatant:
+    return Combatant(
+        id=cid,
+        name=cid,
+        level=level,
+        size="Medium",
+        abilities=AbilityScores(
+            str_score=10, dex_score=dex, con_score=10,
+            int_score=10, wis_score=10, cha_score=10,
+        ),
+        hp_max=hp,
+        ac=ACProfile(total=ac, touch=ac, flat_footed=ac),
+        bab=1,
+        initiative_mod=0,
+        speed_land_ft=30,
+        saves=Saves(fort=0, ref=0, will=0),
+        attacks=list(attacks) or [_melee(cid)],
+        spells=list(spells),
+        spell_slots=spell_slots or {},
+    )
+
+
+def _engine(
+    combatants: list[Combatant],
+    positions: list[tuple[int, int]],
+    rng: list[int],
+    spell_registry: dict[str, SpellSpec] | None = None,
+    policy: PolicyFn | None = None,
+) -> CombatEngine:
+    sides = ["players"] + ["monsters"] * (len(combatants) - 1)
+    states = [
+        CombatantState(combatant=c, side=side, pos=pos, hp=c.hp_max)
+        for c, side, pos in zip(combatants, sides, positions, strict=True)
+    ]
+    legend = {".": TerrainType(type="floor", move_cost=1)}
+    spec = MapSpec(name="test", terrain=tuple(["." * 8] * 8), legend=legend)
+    grid = Grid.from_spec(spec)
+    return CombatEngine(
+        ScriptedRng(rng), grid, states,
+        spell_registry=spell_registry or {}, policy=policy,
+    )
+
+
+def _add_condition(state: CombatantState, cond: Condition) -> None:
+    state.active_conditions.append(
+        ActiveCondition(condition=cond, rounds_left=5, source="test")
+    )
+
+
+# ── B1: point-cast area — every creature rolls the spell's save type ─────────
+
+
+_SLUMBER_CLOUD = SpellSpec(
+    name="Slumber Cloud",
+    level=1,
+    school="enchantment",
+    range="close",
+    save="will",
+    effects=(
+        AreaEffect(
+            radius_ft=20,
+            effects=(ConditionEffect("asleep", 10, save_negates=True),),
+            save_for_half=False,
+        ),
+    ),
+)
+
+
+def test_point_cast_area_rolls_the_spells_save_per_creature() -> None:
+    # No primary target: each creature in the burst rolls its own Will save
+    # (the old code short-circuited save_for_half=False to "no save at all").
+    eng = _engine(
+        [
+            _combatant("caster", spell_slots={1: 1}),
+            _combatant("sleeper"),
+            _combatant("waker"),
+        ],
+        [(0, 7), (0, 2), (0, 3)],
+        [1, 20],
+        spell_registry={"Slumber Cloud": _SLUMBER_CLOUD},
+    )
+    caster, sleeper, waker = eng._states
+    result = eng._execute(
+        caster,
+        Action(kind="cast_spell", spell_name="Slumber Cloud", target_pos=(0, 2)),
+    )
+    assert result.ok
+    # Caster is outside the 4-cell burst; sleeper fails its Will (d20 1),
+    # waker saves on natural 20 — the negate semantics now reach areas.
+    assert not any(ac.condition.name == "asleep" for ac in caster.active_conditions)
+    assert any(ac.condition.name == "asleep" for ac in sleeper.active_conditions)
+    assert not any(ac.condition.name == "asleep" for ac in waker.active_conditions)
+
+
+# ── B3: prone rules by weapon kind ───────────────────────────────────────────
+
+
+def test_prone_attacker_minus4_on_melee_attack() -> None:
+    eng = _engine([_combatant("atk"), _combatant("def")], [(0, 0), (0, 1)], [10, 4])
+    a, d = eng._states
+    _add_condition(a, CONDITIONS_BY_NAME["prone"])
+    result = eng.resolve_attack(a, d, a.combatant.attacks[0])
+    # roll 10 + bonus 5 - 4 (prone melee) = 11.
+    assert result.total == 11
+
+
+def test_prone_defender_minus4_ac_vs_melee_plus4_vs_ranged() -> None:
+    melee_eng = _engine(
+        [_combatant("atk"), _combatant("def")], [(0, 0), (0, 1)], [10, 4]
+    )
+    _add_condition(melee_eng._states[1], CONDITIONS_BY_NAME["prone"])
+    melee = melee_eng.resolve_attack(
+        melee_eng._states[0], melee_eng._states[1], _melee("atk")
+    )
+    assert melee.ac == 11  # 15 - 4 vs melee
+
+    ranged_eng = _engine(
+        [_combatant("atk", attacks=(_bow("atk"),)), _combatant("def")],
+        [(0, 0), (0, 3)],
+        [10, 4],
+    )
+    _add_condition(ranged_eng._states[1], CONDITIONS_BY_NAME["prone"])
+    ranged = ranged_eng.resolve_attack(
+        ranged_eng._states[0], ranged_eng._states[1], _bow("atk")
+    )
+    assert ranged.ac == 19  # 15 + 4 vs ranged
+
+
+def test_prone_ranged_attacker_minus4_crossbow_exemption_documented() -> None:
+    # The model cannot tell a crossbow from a bow: every ranged weapon is
+    # treated as crossbow-exempt — usable, but at -4 while prone.
+    eng = _engine(
+        [_combatant("atk", attacks=(_bow("atk"),)), _combatant("def")],
+        [(0, 0), (0, 3)],
+        [15, 4],
+    )
+    _add_condition(eng._states[0], CONDITIONS_BY_NAME["prone"])
+    result = eng.resolve_attack(
+        eng._states[0], eng._states[1], _bow("atk")
+    )
+    assert result.total == 16  # 15 + 5 - 4
+
+
+# ── B4: spell slots enforced ─────────────────────────────────────────────────
+
+
+_ZAP = SpellSpec(
+    name="Zap",
+    level=1,
+    school="evocation",
+    range="close",
+    save="none",
+    effects=(DamageEffect(formula=parse_dice("1d4"), types=("electricity",)),),
+)
+
+_SPARK = SpellSpec(
+    name="Spark",
+    level=0,
+    school="evocation",
+    range="close",
+    save="none",
+    effects=(DamageEffect(formula=parse_dice("1d3"), types=("electricity",)),),
+)
+
+
+def test_cast_without_a_slot_is_refused() -> None:
+    eng = _engine(
+        [_combatant("caster", spell_slots={1: 1}), _combatant("tgt")],
+        [(0, 0), (0, 2)],
+        [3, 3],
+        spell_registry={"Zap": _ZAP},
+    )
+    caster, tgt = eng._states
+    eng._cast_spell(caster, tgt, "Zap")
+    assert tgt.hp == 97  # first cast spent the only slot (1d4 → 3)
+    eng._cast_spell(caster, tgt, "Zap")
+    assert tgt.hp == 97  # second cast refused before any roll
+    assert any("NO SPELL SLOT" in line for line in eng._transcript)
+    assert caster.spell_slots_left[1] == 0
+
+
+def test_cantrips_cast_freely_without_slots() -> None:
+    eng = _engine(
+        [_combatant("caster"), _combatant("tgt")],
+        [(0, 0), (0, 2)],
+        [3, 3, 3],
+        spell_registry={"Spark": _SPARK},
+    )
+    caster, tgt = eng._states
+    for _ in range(3):
+        eng._cast_spell(caster, tgt, "Spark")
+    assert tgt.hp == 100 - 9  # three casts of 1d3 → 3 each
+    assert not any("NO SPELL SLOT" in line for line in eng._transcript)
+
+
+# ── B5: helpless extended to paralyzed / asleep / unconscious ────────────────
+
+
+def _helpless_cases() -> list[Condition]:
+    return [
+        CONDITIONS_BY_NAME["helpless"],
+        PARALYZED,
+        ASLEEP,
+        Condition(name="unconscious", denies_dex_to_ac=True, cant_act=True),
+    ]
+
+
+def test_melee_vs_helpless_states_gains_plus4_and_dex_zero() -> None:
+    for cond in _helpless_cases():
+        eng = _engine(
+            [_combatant("atk"), _combatant("def", ac=16)], [(0, 0), (0, 1)], [10, 4]
+        )
+        _add_condition(eng._states[1], cond)
+        result = eng.resolve_attack(eng._states[0], eng._states[1], _melee("atk"))
+        # roll 10 + 5 + 4 (helpless melee) = 19; AC 16 (flat-footed, Dex
+        # denied) - 5 (effective Dex 0) = 11.
+        assert result.total == 19, cond.name
+        assert result.ac == 11, cond.name
+
+
+def test_stunned_is_not_helpless() -> None:
+    eng = _engine(
+        [_combatant("atk"), _combatant("def", ac=16)], [(0, 0), (0, 1)], [10, 4]
+    )
+    _add_condition(eng._states[1], CONDITIONS_BY_NAME["stunned"])
+    result = eng.resolve_attack(eng._states[0], eng._states[1], _melee("atk"))
+    # No +4 to hit (stunned is not helpless); AC = flat-footed 16 - 2 (the
+    # stunned condition's own AC penalty), no Dex-0 -5.
+    assert result.total == 15
+    assert result.ac == 14
+
+
+def test_helpless_dex_zero_replaces_a_native_dex_penalty() -> None:
+    # A Dex 8 (-1) helpless target: the -1 penalty gives way to the Dex-0 -5
+    # (adjustment -5 - (-1) = -4 on top of the flat-footed base).
+    eng = _engine(
+        [_combatant("atk"), _combatant("def", ac=14, dex=8)],
+        [(0, 0), (0, 1)],
+        [10, 4],
+    )
+    _add_condition(eng._states[1], PARALYZED)
+    result = eng.resolve_attack(eng._states[0], eng._states[1], _melee("atk"))
+    assert result.ac == 10  # 14 - 4
+
+
+# ── B6: nauseated — single move action only, no casting ──────────────────────
+
+
+def test_nauseated_cannot_take_a_standard_attack() -> None:
+    def policy(_e: CombatEngine, s: CombatantState) -> tuple[Action, ...]:
+        if s.combatant.id == "hero":
+            return (Action(kind="attack", target_id="foe"),)
+        return (Action(kind="wait"),)
+
+    eng = _engine(
+        [_combatant("hero"), _combatant("foe")], [(0, 0), (0, 1)], [10, 5],
+        policy=policy,
+    )
+    hero, _foe = eng._states
+    _add_condition(hero, CONDITIONS_BY_NAME["nauseated"])
+    eng._roll_initiative()
+    eng._take_turn(hero)
+    assert not any(
+        " vs foe" in line and "short sword" in line for line in eng._transcript
+    )
+    assert hero.last_action_results == [
+        ActionResult(kind="attack", ok=False, reason="downgraded:nauseated")
+    ]
+
+
+def test_nauseated_keeps_only_the_first_move_action() -> None:
+    def policy(_e: CombatEngine, s: CombatantState) -> tuple[Action, ...]:
+        if s.combatant.id == "hero":
+            return (
+                Action(kind="move", target_id="foe"),
+                Action(kind="attack", target_id="foe"),
+            )
+        return (Action(kind="wait"),)
+
+    eng = _engine(
+        [_combatant("hero"), _combatant("foe")], [(0, 0), (0, 3)], [10, 5],
+        policy=policy,
+    )
+    hero, _foe = eng._states
+    _add_condition(hero, CONDITIONS_BY_NAME["nauseated"])
+    eng._roll_initiative()
+    eng._take_turn(hero)
+    assert any("hero: move" in line for line in eng._transcript)
+    assert hero.last_action_results == [
+        ActionResult(kind="attack", ok=False, reason="downgraded:nauseated"),
+        ActionResult(kind="move", ok=True, reason="ok"),
+    ]
+
+
+def test_nauseated_cannot_cast_via_action_execution() -> None:
+    # Defense in depth: even a cast that bypasses the action filter (a ready
+    # payload, say) is refused while nauseated.
+    eng = _engine(
+        [_combatant("caster", spell_slots={1: 9}), _combatant("tgt")],
+        [(0, 0), (0, 2)],
+        [],
+        spell_registry={"Zap": _ZAP},
+    )
+    caster, tgt = eng._states
+    _add_condition(caster, CONDITIONS_BY_NAME["nauseated"])
+    eng._execute_cast_spell(caster, tgt, "Zap")
+    assert tgt.hp == 100
+    assert caster.spell_slots_left[1] == 9
+    assert any(
+        "cast_spell rejected (cannot attack)" in line for line in eng._transcript
+    )
+
+
+def test_nauseated_filter_keeps_move_kinds_drops_everything_else() -> None:
+    for kind in ("move", "5foot_step", "stand_up", "drop_prone"):
+        kept = _nauseated_filter((Action(kind=kind, target_id="foe"),))
+        assert len(kept) == 1, kind
+        assert kept[0].kind == kind, kind
+    for kind in ("attack", "cast_spell", "full_attack", "charge", "maneuver", "hex"):
+        assert _nauseated_filter((Action(kind=kind, target_id="foe"),)) == (), kind
+
+
+# ── B3/B5 engine-side locks (unit level) ────────────────────────────────────
+
+
+def test_stat_modifiers_no_longer_flatten_prone_or_paralyzed_ac() -> None:
+    # The unconditional -4 AC appends for prone/paralyzed are gone from
+    # _stat_modifiers: the adjustments are weapon-kind dependent and live in
+    # resolve_attack. A prone + paralyzed defender's collected "ac" mods
+    # carry no -4.
+    eng = _engine([_combatant("a"), _combatant("b")], [(0, 0), (0, 1)], [])
+    _add_condition(eng._states[1], CONDITIONS_BY_NAME["prone"])
+    _add_condition(eng._states[1], PARALYZED)
+    mods = eng._stat_modifiers(eng._states[1], "ac")
+    assert all(m.value != -4 for m in mods)
+
+
+def test_asleep_condition_no_longer_carries_a_flat_ac_penalty() -> None:
+    # The ASLEEP -4 AC approximation is superseded by the engine's Dex-0
+    # adjustment for helpless targets.
+    assert ASLEEP.modifiers == ()
diff --git a/tests/test_immediate_actions.py b/tests/test_immediate_actions.py
index eeeb5b7..43ae7c2 100644
--- a/tests/test_immediate_actions.py
+++ b/tests/test_immediate_actions.py
@@ -312,6 +312,7 @@ def test_damage_taken_reaction_fires() -> None:
     caster = make_combatant("caster", hp=50)
     reactor = make_combatant("reactor", hp=50, kind="ranged")
     caster_state = make_state(caster, "players", (1, 1))
+    caster_state.spell_slots_left = {1: 9}
     reactor_state = make_state(reactor, "monsters", (1, 3))
     states = [caster_state, reactor_state]
 
diff --git a/tests/test_observation_enriched.py b/tests/test_observation_enriched.py
index 938bc61..a3b81ae 100644
--- a/tests/test_observation_enriched.py
+++ b/tests/test_observation_enriched.py
@@ -57,6 +57,7 @@ def make_combatant(
     features: list[AbilitySpec] | None = None,
     spells: list[str] | None = None,
     ranged: bool = False,
+    spell_slots: dict[int, int] | None = None,
 ) -> Combatant:
     """Build a single-weapon combatant with known static stats.
 
@@ -103,6 +104,7 @@ def make_combatant(
         attacks=[attack],
         features=features or [],
         spells=spells or [],
+        spell_slots=spell_slots or {},
     )
 
 
diff --git a/tests/test_point_targeting.py b/tests/test_point_targeting.py
index 1729dfb..501b86e 100644
--- a/tests/test_point_targeting.py
+++ b/tests/test_point_targeting.py
@@ -108,7 +108,9 @@ def _cast_scene(
     (distance 0) but not foe_out (distance 5) nor the caster (distance 9).
     """
     caster = make_state(
-        make_combatant("caster", hp=100, spells=["Fireball"]), "players", (7, 0)
+        make_combatant(
+            "caster", hp=100, spells=["Fireball"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (7, 0)
     )
     foe_in = make_state(make_combatant("foe_in", hp=100), "monsters", (0, 4))
     foe_out = make_state(make_combatant("foe_out", hp=100), "monsters", (4, 7))
@@ -187,7 +189,9 @@ def test_point_cast_without_line_of_effect_rejected() -> None:
     When: cast_spell at that unseen point
     Then: invalid_destination rejection without casting."""
     caster = make_state(
-        make_combatant("caster", hp=100, spells=["Fireball"]), "players", (0, 0)
+        make_combatant(
+            "caster", hp=100, spells=["Fireball"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (0, 0)
     )
     foe = make_state(make_combatant("foe", hp=100), "monsters", (0, 6))
     eng = _engine([caster, foe], [], grid=_walled_grid())
@@ -216,7 +220,9 @@ def test_point_cast_rolls_a_save_per_creature_in_area() -> None:
     When: a target-less point cast at (0,4)
     Then: no primary save is rolled (queue would shift otherwise) and EACH
     creature rolls its own: foe_a fails (2) full 24, foe_b saves (20) half 12."""
-    caster = make_state(make_combatant("caster", hp=100, spells=["Fireball"]), "players", (7, 0))
+    caster = make_state(make_combatant(
+            "caster", hp=100, spells=["Fireball"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (7, 0))
     foe_a = make_state(make_combatant("foe_a", hp=100), "monsters", (0, 4))
     foe_b = make_state(make_combatant("foe_b", hp=100), "monsters", (0, 5))
     eng = _engine([caster, foe_a, foe_b], [2] + [3] * 8 + [20] + [3] * 8)
@@ -233,7 +239,9 @@ def test_point_cast_no_save_area_spell_rolls_damage_dice_only() -> None:
     When: a target-less point cast
     Then: no saving throw is rolled at all — only the 8 damage dice."""
     caster = make_state(
-        make_combatant("caster", hp=100, spells=["Spark Burst"]), "players", (7, 0)
+        make_combatant(
+            "caster", hp=100, spells=["Spark Burst"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (7, 0)
     )
     foe = make_state(make_combatant("foe", hp=100), "monsters", (0, 4))
     eng = _engine([caster, foe], [3] * 8)
@@ -254,7 +262,9 @@ def test_creature_centered_cast_transcript_pinned() -> None:
     When: cast_spell with target_id and NO target_pos (the legacy path)
     Then: the transcript is the pinned creature-centered line — primary save
     rolled once, reused for the target in the area, 8d6 all 3s."""
-    caster = make_state(make_combatant("caster", hp=100, spells=["Fireball"]), "players", (7, 0))
+    caster = make_state(make_combatant(
+            "caster", hp=100, spells=["Fireball"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (7, 0))
     foe = make_state(make_combatant("foe", hp=100), "monsters", (0, 4))
     eng = _engine([caster, foe], [2] + [3] * 8)
     result = eng._execute(
@@ -276,13 +286,17 @@ def test_target_pos_at_target_cell_matches_creature_centered() -> None:
     target_pos set to the target's own cell (target_id kept)
     When: both casts resolve with identical scripted rolls
     Then: transcripts and hp outcomes are byte-identical."""
-    caster = make_state(make_combatant("caster", hp=100, spells=["Fireball"]), "players", (7, 0))
+    caster = make_state(make_combatant(
+            "caster", hp=100, spells=["Fireball"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (7, 0))
     foe = make_state(make_combatant("foe", hp=100), "monsters", (0, 4))
     plain = _engine([caster, foe], [2] + [3] * 8)
     plain._execute(
         caster, Action(kind="cast_spell", target_id="foe", spell_name="Fireball")
     )
-    caster2 = make_state(make_combatant("caster", hp=100, spells=["Fireball"]), "players", (7, 0))
+    caster2 = make_state(make_combatant(
+            "caster", hp=100, spells=["Fireball"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (7, 0))
     foe2 = make_state(make_combatant("foe", hp=100), "monsters", (0, 4))
     pointed = _engine([caster2, foe2], [2] + [3] * 8)
     pointed._execute(
@@ -304,7 +318,9 @@ def test_non_area_spell_with_target_pos_resolves_on_target() -> None:
     Then: target_pos is ignored — the missile hits its creature (1d4+1 = 4)
     and the transcript is the ordinary creature-centered line."""
     caster = make_state(
-        make_combatant("caster", hp=100, spells=["Magic Missile"]), "players", (0, 0)
+        make_combatant(
+            "caster", hp=100, spells=["Magic Missile"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (0, 0)
     )
     foe = make_state(make_combatant("foe", hp=100), "monsters", (0, 2))
     eng = _engine([caster, foe], [3])
@@ -325,7 +341,9 @@ def test_non_area_point_cast_without_target_is_harmless_no_op() -> None:
     When: the action is dispatched with an empty roll queue
     Then: nothing crashes, nothing is cast, no die is rolled."""
     caster = make_state(
-        make_combatant("caster", hp=100, spells=["Magic Missile"]), "players", (0, 0)
+        make_combatant(
+            "caster", hp=100, spells=["Magic Missile"], spell_slots={1: 9, 2: 9, 3: 9}
+        ), "players", (0, 0)
     )
     foe = make_state(make_combatant("foe", hp=100), "monsters", (0, 2))
     eng = _engine([caster, foe], [])
diff --git a/tests/test_prone_actions.py b/tests/test_prone_actions.py
index 27710af..2994e19 100644
--- a/tests/test_prone_actions.py
+++ b/tests/test_prone_actions.py
@@ -7,8 +7,10 @@ removes the ``prone`` condition from BOTH representations — the duration-track
 ``conditions`` list (how ``drop_prone`` applies it). ``drop_prone`` is a free
 action that goes prone until the combatant stands up. Rejections: standing up
 while not prone → ``not_prone``; dropping while already prone →
-``already_prone``. The engine's existing prone behaviour (flat -4 AC in
-``_stat_modifiers``, -4 ranged attacks) is unchanged.
+``already_prone``. The engine's prone modifiers follow the CRB (B3
+conformance): a prone attacker takes -4 on melee attacks (ranged weapons are
+treated as crossbow-exempt — usable at -4, the model cannot tell them apart);
+a prone defender takes -4 AC vs melee and gains +4 AC vs ranged.
 """
 from __future__ import annotations
 
diff --git a/tests/test_spell_resistance.py b/tests/test_spell_resistance.py
index 9e0c06f..8f9dc9f 100644
--- a/tests/test_spell_resistance.py
+++ b/tests/test_spell_resistance.py
@@ -24,6 +24,7 @@ def _make_combatant(
     spell_resistance: int = 0,
     resistances: dict[str, int] | None = None,
     immunities: tuple[str, ...] = (),
+    spell_slots: dict[int, int] | None = None,
 ) -> Combatant:
     return Combatant(
         id=id_,
@@ -43,6 +44,7 @@ def _make_combatant(
         spell_resistance=spell_resistance,
         resistances=resistances or {},
         immunities=immunities,
+        spell_slots=spell_slots or {},
     )
 
 
@@ -102,7 +104,7 @@ _FIREBALL = SpellSpec(
 
 
 def test_sr_blocks_all_effects() -> None:
-    caster = _make_combatant("caster", spell_resistance=0)
+    caster = _make_combatant("caster", spell_resistance=0, spell_slots={1: 9, 3: 9})
     target = _make_combatant("target", spell_resistance=15)
     eng = _engine(
         [caster, target], [(0, 0), (0, 2)], ["players", "monsters"],
@@ -116,7 +118,7 @@ def test_sr_blocks_all_effects() -> None:
 
 
 def test_sr_passes_when_cl_suffices() -> None:
-    caster = _make_combatant("caster", spell_resistance=0)
+    caster = _make_combatant("caster", spell_resistance=0, spell_slots={1: 9, 3: 9})
     target = _make_combatant("target", spell_resistance=10)
     eng = _engine(
         [caster, target], [(0, 0), (0, 2)], ["players", "monsters"],
@@ -130,7 +132,7 @@ def test_sr_passes_when_cl_suffices() -> None:
 
 
 def test_per_target_sr_in_area_spell() -> None:
-    caster = _make_combatant("caster", spell_resistance=0)
+    caster = _make_combatant("caster", spell_resistance=0, spell_slots={1: 9, 3: 9})
     t1 = _make_combatant("t1", spell_resistance=15)
     t2 = _make_combatant("t2", spell_resistance=0)
     eng = _engine(
@@ -149,7 +151,7 @@ def test_per_target_sr_in_area_spell() -> None:
 
 
 def test_no_sr_check_when_sr_zero() -> None:
-    caster = _make_combatant("caster", spell_resistance=0)
+    caster = _make_combatant("caster", spell_resistance=0, spell_slots={1: 9, 3: 9})
     target = _make_combatant("target", spell_resistance=0)
     eng = _engine(
         [caster, target], [(0, 0), (0, 2)], ["players", "monsters"],
@@ -164,7 +166,7 @@ def test_no_sr_check_when_sr_zero() -> None:
 
 
 def test_fire_resistance_reduces_spell_damage() -> None:
-    caster = _make_combatant("caster", spell_resistance=0)
+    caster = _make_combatant("caster", spell_resistance=0, spell_slots={1: 9, 3: 9})
     target = _make_combatant(
         "target",
         spell_resistance=0,
@@ -182,7 +184,7 @@ def test_fire_resistance_reduces_spell_damage() -> None:
 
 
 def test_fire_immunity_negates_damage() -> None:
-    caster = _make_combatant("caster", spell_resistance=0)
+    caster = _make_combatant("caster", spell_resistance=0, spell_slots={1: 9, 3: 9})
     target = _make_combatant(
         "target",
         spell_resistance=0,
diff --git a/tests/test_spells.py b/tests/test_spells.py
index f128598..772cf0c 100644
--- a/tests/test_spells.py
+++ b/tests/test_spells.py
@@ -73,6 +73,9 @@ def _make_caster(cid: str = "caster", *, level: int = 5) -> Combatant:
         saves=Saves(fort=3, ref=4, will=4),
         attacks=[attack],
         casting_ability="int",
+        # B4 conformance: _cast_spell now refuses without a slot; test
+        # casters carry a generous pool so fixtures stay about spells.
+        spell_slots={0: 99, 1: 99, 2: 99, 3: 99, 4: 99, 5: 99, 6: 99},
     )
 
 
@@ -260,6 +263,64 @@ class TestFireballSave:
         assert any("SAVED" in line for line in engine._transcript)
 
 
+class TestAreaSavesPerSpellSaveType:
+    """B1 (PF1e conformance): every creature in an area rolls the save the
+    SPELL lists (Will/Fort/Ref) — "save negates" areas are no longer
+    save-free, and secondary creatures do not always roll Reflex."""
+
+    def test_sleep_secondary_creature_rolls_will_and_negates(self) -> None:
+        # Sleep (Will negates, save_for_half=False): primary target saves on
+        # natural 20 (first roll), the caster — second creature in the area —
+        # rolls its own Will and fails on natural 1 (second roll).
+        caster = _make_caster()
+        target = _make_target(hp_max=100)
+        engine, c, t = _make_engine(
+            caster, target, [20, 1], target_pos=(2, 0)
+        )
+        engine._cast_spell(c, t, "Sleep")
+        assert not any(ac.condition.name == "asleep" for ac in t.active_conditions)
+        assert any(ac.condition.name == "asleep" for ac in c.active_conditions)
+
+    def test_color_spray_primary_save_is_not_discarded(self) -> None:
+        # Color Spray (Will negates): the primary's pre-rolled save decides —
+        # natural 1 fails (stunned), the caster's own natural 20 succeeds.
+        caster = _make_caster()
+        target = _make_target(hp_max=100)
+        engine, c, t = _make_engine(
+            caster, target, [1, 20], target_pos=(2, 0)
+        )
+        engine._cast_spell(c, t, "Color Spray")
+        assert any(ac.condition.name == "stunned" for ac in t.active_conditions)
+        assert not any(ac.condition.name == "stunned" for ac in c.active_conditions)
+
+    def test_web_secondary_creature_rolls_reflex(self) -> None:
+        # Web (Reflex negates): secondary creature rolls its own Reflex.
+        caster = _make_caster()
+        target = _make_target(hp_max=100)
+        engine, c, t = _make_engine(
+            caster, target, [20, 1], target_pos=(2, 0)
+        )
+        engine._cast_spell(c, t, "Web")
+        assert not any(ac.condition.name == "grappled" for ac in t.active_conditions)
+        assert any(ac.condition.name == "grappled" for ac in c.active_conditions)
+
+    def test_sound_burst_secondary_rolls_fortitude_not_reflex(self) -> None:
+        # Sound Burst (Fortitude partial): caster has ref +4, fort +3 and the
+        # DC is 16 — d20 12 passes Reflex but fails Fortitude. The caster
+        # being stunned proves the FORT save was rolled (B1's hardcoded ref
+        # would have "saved" and left the caster unstunned).
+        caster = _make_caster()
+        target = _make_target(hp_max=200)
+        # rolls: primary (target) fort 20 = save; caster fort 12 = fail;
+        # then the 1d8 damage dice for each creature in state order.
+        engine, c, t = _make_engine(
+            caster, target, [20, 12, 3, 3], target_pos=(2, 0)
+        )
+        engine._cast_spell(c, t, "Sound Burst")
+        assert any(ac.condition.name == "stunned" for ac in c.active_conditions)
+        assert t.hp == 200 - 1  # saved: 3 // 2
+
+
 class TestTargetedSpellSaveNegates:
     """Given: a targeted spell with a save (half_on_save=False)
     When: the target succeeds / fails its save