feat(conditions): add condition system with 18 PF1e conditions

src/pf1e_simulator/conditions.py

@@ -0,0 +1,210 @@
+"""PF1e conditions: predefined stat modifiers and behavioral flags.
+
+Each condition maps to a set of StatModifier effects (applied via
+resolve_modifiers with PF1e stacking rules) and optional behavioral flags
+that the engine checks at relevant resolution points.
+
+Behavioral flags are declared here but only stat modifiers are integrated
+into resolve_attack/resolve_save in this step. Flag enforcement (cant_act,
+must_flee, etc.) will be added incrementally with spell/condition application.
+
+Sources: PRPG Core Rulebook, Conditions chapter.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+from pf1e_simulator.effects import StatModifier
+
+
+@dataclass(frozen=True)
+class Condition:
+    """A PF1e condition: stat modifiers + behavioral flags.
+
+    ``modifiers`` are collected alongside transient ``effects`` by
+    ``resolve_modifiers``. Behavioral flags are checked by the engine at
+    relevant points (e.g. ``cant_act`` in ``_take_turn``).
+    """
+
+    name: str
+    modifiers: tuple[StatModifier, ...] = ()
+    denies_dex_to_ac: bool = False
+    cant_act: bool = False
+    cant_move: bool = False
+    cant_attack: bool = False
+    cant_charge: bool = False
+    cant_aoo: bool = False
+    must_flee: bool = False
+    speed_mult: float = 1.0
+
+
+# ── Fear conditions ──────────────────────────────────────────────────────────
+# Shaken: -2 attack rolls, saving throws, skill checks, ability checks (CRB)
+SHAKEN = Condition(
+    name="shaken",
+    modifiers=(
+        StatModifier(target="attack", value=-2),
+        StatModifier(target="fort", value=-2),
+        StatModifier(target="ref", value=-2),
+        StatModifier(target="will", value=-2),
+    ),
+)
+
+# Frightened: shaken penalties + must flee from source of fear (CRB)
+FRIGHTENED = Condition(
+    name="frightened",
+    modifiers=(
+        StatModifier(target="attack", value=-2),
+        StatModifier(target="fort", value=-2),
+        StatModifier(target="ref", value=-2),
+        StatModifier(target="will", value=-2),
+    ),
+    must_flee=True,
+)
+
+# Panicked: drop items + flee at top speed + -2 saves (CRB)
+PANICKED = Condition(
+    name="panicked",
+    modifiers=(
+        StatModifier(target="fort", value=-2),
+        StatModifier(target="ref", value=-2),
+        StatModifier(target="will", value=-2),
+    ),
+    must_flee=True,
+)
+
+# Cowering: frozen in fear, can't act, -2 AC, loses Dex (CRB)
+COWERING = Condition(
+    name="cowering",
+    modifiers=(
+        StatModifier(target="ac", value=-2),
+    ),
+    denies_dex_to_ac=True,
+    cant_act=True,
+)
+
+# ── Physical conditions ─────────────────────────────────────────────────────
+# Sickened: -2 attack, weapon damage, saving throws, skill/ability checks (CRB)
+SICKENED = Condition(
+    name="sickened",
+    modifiers=(
+        StatModifier(target="attack", value=-2),
+        StatModifier(target="damage", value=-2),
+        StatModifier(target="fort", value=-2),
+        StatModifier(target="ref", value=-2),
+        StatModifier(target="will", value=-2),
+    ),
+)
+
+# Fatigued: -2 STR, -2 DEX; can't run or charge (CRB)
+# Approximation: -1 attack (STR/DEX), -1 damage (STR)
+FATIGUED = Condition(
+    name="fatigued",
+    modifiers=(
+        StatModifier(target="attack", value=-1),
+        StatModifier(target="damage", value=-1),
+    ),
+    cant_charge=True,
+)
+
+# Exhausted: -6 STR, -6 DEX; half speed; can't run or charge (CRB)
+# Approximation: -3 attack, -3 damage
+EXHAUSTED = Condition(
+    name="exhausted",
+    modifiers=(
+        StatModifier(target="attack", value=-3),
+        StatModifier(target="damage", value=-3),
+    ),
+    cant_charge=True,
+    speed_mult=0.5,
+)
+
+# Entangled: -2 attack, -4 DEX; half speed; can't run or charge (CRB)
+# Approximation: -2 attack, -2 AC (from -4 DEX), -2 ref (from -4 DEX)
+ENTANGLED = Condition(
+    name="entangled",
+    modifiers=(
+        StatModifier(target="attack", value=-2),
+        StatModifier(target="ac", value=-2),
+        StatModifier(target="ref", value=-2),
+    ),
+    cant_charge=True,
+    speed_mult=0.5,
+)
+
+# ── Sensory conditions ──────────────────────────────────────────────────────
+# Dazzled: -1 attack rolls (CRB)
+DAZZLED = Condition(
+    name="dazzled",
+    modifiers=(
+        StatModifier(target="attack", value=-1),
+    ),
+)
+
+# Blinded: -2 AC, loses Dex, -4 STR/DEX skill checks (CRB)
+BLINDED = Condition(
+    name="blinded",
+    modifiers=(
+        StatModifier(target="ac", value=-2),
+        StatModifier(target="attack", value=-2),
+    ),
+    denies_dex_to_ac=True,
+)
+
+# Deafened: -4 initiative, 20% spell failure (verbal) (CRB)
+DEAFENED = Condition(
+    name="deafened",
+    modifiers=(
+        StatModifier(target="initiative", value=-4),
+    ),
+)
+
+# ── Positional conditions ────────────────────────────────────────────────────
+# Flat-footed: loses Dex to AC, can't make AoO (CRB)
+FLAT_FOOTED = Condition(
+    name="flat_footed",
+    denies_dex_to_ac=True,
+    cant_aoo=True,
+)
+
+# Prone: -4 melee attack, +4 AC vs ranged, -4 AC vs melee (CRB)
+PRONE = Condition(
+    name="prone",
+)
+
+# ── Incapacitating conditions ────────────────────────────────────────────────
+# Stunned: can't act, -2 AC, loses Dex (CRB)
+STUNNED = Condition(
+    name="stunned",
+    modifiers=(
+        StatModifier(target="ac", value=-2),
+    ),
+    denies_dex_to_ac=True,
+    cant_act=True,
+)
+
+# Paralyzed: can't move or act, effective STR/DEX = 0, helpless (CRB)
+PARALYZED = Condition(
+    name="paralyzed",
+    denies_dex_to_ac=True,
+    cant_act=True,
+    cant_move=True,
+)
+
+# Nauseated: can't attack/cast/concentrate; only single move action (CRB)
+NAUSEATED = Condition(
+    name="nauseated",
+    cant_attack=True,
+)
+
+# Dazed: can't act, no AC penalty (CRB)
+DAZED = Condition(
+    name="dazed",
+    cant_act=True,
+)
+
+# Staggered: only single move or standard action, no full-round (CRB)
+STAGGERED = Condition(
+    name="staggered",
+)