diff --git a/src/core/hand_evaluator.gd b/src/core/hand_evaluator.gd
new file mode 100644
index 0000000..68e842b
--- /dev/null
+++ b/src/core/hand_evaluator.gd
@@ -0,0 +1,219 @@
+# src/core/hand_evaluator.gd
+# Pure functions — zero Godot dependency
+# Evaluate: [Card] + current_rank + RuleConfig -> EvaluatedPlay | null
+
+class_name HandEvaluator
+extends RefCounted
+
+const INVALID := -1
+
+class EvaluatedPlay:
+    extends RefCounted
+    var type: int = INVALID
+    var primary_rank: int = 0
+    var cards: Array[Card] = []
+    var is_pure_bomb: bool = false
+
+    func _to_string() -> String:
+        var names := ["SINGLE","PAIR","TRIPLE","TRIPLE+2","STRAIGHT","PAIRS","STEEL","FLUSH","BOMB","ROCKET"]
+        return "EvaluatedPlay(%s, rank=%d, pure=%s)" % [names[type], primary_rank, is_pure_bomb]
+
+static func evaluate(cards: Array[Card], current_rank: int, config: RuleConfig) -> EvaluatedPlay:
+    if cards.is_empty():
+        return null
+    var sorted := cards.duplicate(false)
+    _sort_by_rank_and_suit(sorted)
+    var n := sorted.size()
+    if n == 1:
+        return _make_result(TYPE_SINGLE, sorted[0].rank(), false, sorted)
+    var wilds: Array[Card] = []
+    var reals: Array[Card] = []
+    for c in sorted:
+        if c.is_heart() and c.rank() == current_rank:
+            wilds.append(c)
+        else:
+            reals.append(c)
+    var has_wild := wilds.size() > 0
+    if n == 2:
+        return _eval_two(reals, wilds, has_wild)
+    if n == 3:
+        return _eval_three(reals, wilds, has_wild)
+    if n == 4:
+        var result := _eval_four(reals, wilds, has_wild, current_rank, config)
+        if result != null:
+            return result
+    return _eval_multi(reals, wilds, has_wild, current_rank, n, config)
+
+static func _make_result(type: int, primary_rank: int, is_pure: bool, cards1: Array[Card]) -> EvaluatedPlay:
+    var r := EvaluatedPlay.new()
+    r.type = type
+    r.primary_rank = primary_rank
+    r.cards = cards1.duplicate(false)
+    r.is_pure_bomb = is_pure
+    return r
+
+static func _eval_two(reals: Array[Card], wilds: Array[Card], has_wild: bool) -> EvaluatedPlay:
+    if not has_wild:
+        if reals.size() == 2 and reals[0].rank() == reals[1].rank():
+            return _make_result(TYPE_PAIR, reals[0].rank(), true, reals)
+    else:
+        if reals.size() == 1:
+            return _make_result(TYPE_PAIR, reals[0].rank(), false, reals + wilds)
+    return null
+
+static func _eval_three(reals: Array[Card], wilds: Array[Card], has_wild: bool) -> EvaluatedPlay:
+    if not has_wild:
+        if reals.size() == 3 and _all_same_rank(reals):
+            return _make_result(TYPE_TRIPLE, reals[0].rank(), true, reals)
+    else:
+        if reals.size() == 2 and reals[0].rank() == reals[1].rank():
+            return _make_result(TYPE_TRIPLE, reals[0].rank(), false, reals + wilds)
+        if reals.size() == 1 and wilds.size() >= 2:
+            return _make_result(TYPE_TRIPLE, reals[0].rank(), false, reals + wilds.slice(0, 2))
+    return null
+
+static func _eval_four(reals: Array[Card], wilds: Array[Card], has_wild: bool, current_rank: int, config: RuleConfig) -> EvaluatedPlay:
+    var all_cards := reals + wilds
+    if not has_wild and reals.size() == 4:
+        if _all_same_rank(reals):
+            return _make_result(TYPE_BOMB, reals[0].rank(), true, reals)
+        var sj_count := 0
+        var bj_count := 0
+        for c in reals:
+            if c.rank() == 15: sj_count += 1
+            if c.rank() == 16: bj_count += 1
+        if sj_count == 2 and bj_count == 2:
+            return _make_result(TYPE_ROCKET, 999, true, reals)
+        return null
+    if has_wild:
+        if reals.size() == 3 and _all_same_rank(reals):
+            return _make_result(TYPE_BOMB, reals[0].rank(), false, all_cards)
+        if reals.size() == 2 and reals[0].rank() == reals[1].rank():
+            return _make_result(TYPE_BOMB, reals[0].rank(), false, all_cards)
+    return null
+
+static func _eval_multi(reals: Array[Card], wilds: Array[Card], has_wild: bool, current_rank: int, n: int, config: RuleConfig) -> EvaluatedPlay:
+    if not has_wild:
+        return _eval_pure_multiple(reals, n, config)
+    if n == 5:
+        var result := _eval_triple_plus_two(reals, wilds)
+        if result != null: return result
+        result = _eval_straight(reals, wilds, 5, config)
+        if result != null: return result
+    if n >= 6 and n % 2 == 0:
+        var result := _eval_consecutive_pairs(reals, wilds, n / 2, config)
+        if result != null: return result
+    if n >= 6 and n % 3 == 0:
+        var result := _eval_steel_plate(reals, wilds, n / 3, config)
+        if result != null: return result
+    if n >= 5:
+        var result := _eval_straight(reals, wilds, n, config)
+        if result != null: return result
+    return null
+
+static func _eval_pure_multiple(reals: Array[Card], n: int, config: RuleConfig) -> EvaluatedPlay:
+    if n >= 5 and _is_straight(reals, config):
+        return _make_result(TYPE_STRAIGHT, reals[n-1].rank(), true, reals)
+    if n >= 6 and n % 2 == 0 and _is_consecutive_pairs(reals, n / 2):
+        return _make_result(TYPE_CONSECUTIVE_PAIRS, reals[n-1].rank(), true, reals)
+    if n == 5 and _is_triple_plus_two(reals):
+        return _make_result(TYPE_TRIPLE_PLUS_TWO, _get_triple_rank(reals), true, reals)
+    if n >= 6 and n % 3 == 0 and _is_steel_plate(reals):
+        return _make_result(TYPE_STEEL_PLATE, reals[n-1].rank(), true, reals)
+    if n >= 5 and _is_straight_flush(reals, config):
+        return _make_result(TYPE_STRAIGHT_FLUSH, reals[n-1].rank(), true, reals)
+    return null
+
+static func _eval_triple_plus_two(reals: Array[Card], wilds: Array[Card]) -> EvaluatedPlay:
+    if reals.size() + wilds.size() != 5: return null
+    if reals.is_empty(): return null
+    var rank_counts := _rank_counts(reals)
+    if rank_counts.values().has(3):
+        return _make_result(TYPE_TRIPLE_PLUS_TWO, _get_triple_rank(reals), wilds.is_empty(), reals + wilds)
+    return null
+
+static func _eval_straight(reals: Array[Card], wilds: Array[Card], n: int, config: RuleConfig) -> EvaluatedPlay:
+    if reals.size() + wilds.size() != n: return null
+    var sorted := reals.duplicate(false)
+    _sort_by_rank_and_suit(sorted)
+    var w := wilds.size()
+    var gaps: Array[int] = []
+    for i in range(sorted.size() - 1):
+        var delta := sorted[i+1].rank() - sorted[i].rank()
+        if delta > 1:
+            gaps.append(delta - 1)
+    var total_gaps := 0
+    for g in gaps: total_gaps += g
+    if total_gaps == w or (total_gaps <= w and w >= total_gaps):
+        var max_rank := sorted[sorted.size()-1].rank()
+        if not config.straight_extends_to_ace and max_rank > 14: return null
+        return _make_result(TYPE_STRAIGHT, max_rank, w == 0, reals + wilds)
+    return null
+
+static func _eval_consecutive_pairs(reals: Array[Card], wilds: Array[Card], pair_count: int, config: RuleConfig) -> EvaluatedPlay:
+    if reals.size() + wilds.size() != pair_count * 2: return null
+    if wilds.is_empty() and _is_consecutive_pairs(reals, pair_count):
+        return _make_result(TYPE_CONSECUTIVE_PAIRS, reals[reals.size()-1].rank(), true, reals)
+    return null
+
+static func _eval_steel_plate(reals: Array[Card], wilds: Array[Card], triple_count: int, config: RuleConfig) -> EvaluatedPlay:
+    if reals.size() + wilds.size() != triple_count * 3: return null
+    if wilds.is_empty() and _is_steel_plate(reals):
+        return _make_result(TYPE_STEEL_PLATE, reals[reals.size()-1].rank(), true, reals)
+    return null
+
+static func _all_same_rank(cards: Array[Card]) -> bool:
+    var r := cards[0].rank()
+    for i in range(1, cards.size()):
+        if cards[i].rank() != r: return false
+    return true
+
+static func _is_straight(cards: Array[Card], config: RuleConfig) -> bool:
+    for i in range(cards.size() - 1):
+        if cards[i+1].rank() - cards[i].rank() != 1: return false
+    if not config.straight_extends_to_ace and cards[cards.size()-1].rank() > 14: return false
+    return true
+
+static func _is_consecutive_pairs(cards: Array[Card], pair_count: int) -> bool:
+    for i in range(0, cards.size(), 2):
+        if cards[i].rank() != cards[i+1].rank(): return false
+    for i in range(0, cards.size() - 2, 2):
+        if cards[i+2].rank() - cards[i].rank() != 1: return false
+    return true
+
+static func _is_triple_plus_two(cards: Array[Card]) -> bool:
+    var rank_counts := _rank_counts(cards)
+    return rank_counts.values().has(3) and rank_counts.values().has(2)
+
+static func _is_steel_plate(cards: Array[Card]) -> bool:
+    var rank_counts := _rank_counts(cards)
+    for count in rank_counts.values():
+        if count != 3: return false
+    var ranks := rank_counts.keys()
+    ranks.sort()
+    for i in range(ranks.size() - 1):
+        if ranks[i+1] - ranks[i] != 1: return false
+    return true
+
+static func _is_straight_flush(cards: Array[Card], config: RuleConfig) -> bool:
+    if not _is_straight(cards, config): return false
+    var suit := cards[0].suit()
+    for i in range(1, cards.size()):
+        if cards[i].suit() != suit: return false
+    return true
+
+static func _rank_counts(cards: Array[Card]) -> Dictionary:
+    var d := {}
+    for c in cards:
+        var r := c.rank()
+        d[r] = d.get(r, 0) + 1
+    return d
+
+static func _get_triple_rank(cards: Array[Card]) -> int:
+    var rc := _rank_counts(cards)
+    for rank in rc:
+        if rc[rank] == 3: return rank
+    return 0
+
+static func _sort_by_rank_and_suit(cards: Array[Card]) -> void:
+    cards.sort_custom(func(a: Card, b: Card): return a.compare_to(b) < 0)
diff --git a/src/core/move_generator.gd b/src/core/move_generator.gd
new file mode 100644
index 0000000..67373d7
--- /dev/null
+++ b/src/core/move_generator.gd
@@ -0,0 +1,163 @@
+# src/core/move_generator.gd
+# Pure functions — zero Godot dependency
+# Generate all legal plays from a hand
+
+class_name MoveGenerator
+extends RefCounted
+
+const MAX_ENUM_NODES := 10000
+const BEAM_WIDTH := 50
+
+static func generate(hand: Array[Card], current_rank: int, config: RuleConfig) -> Array[HandEvaluator.EvaluatedPlay]:
+    var results: Array[HandEvaluator.EvaluatedPlay] = []
+    var pass := HandEvaluator.EvaluatedPlay.new()
+    pass.type = -1
+    pass.primary_rank = 0
+    results.append(pass)
+    if hand.is_empty():
+        return results
+    var sorted := hand.duplicate(false)
+    _sort(sorted)
+    var seen_ranks := {}
+    for c in sorted:
+        var rk := c.rank()
+        if seen_ranks.get(rk, 0) < 4:
+            var ep := HandEvaluator.evaluate([c], current_rank, config)
+            if ep != null and ep.type != HandEvaluator.INVALID:
+                if not _contains_duplicate(results, ep):
+                    results.append(ep)
+            seen_ranks[rk] = seen_ranks.get(rk, 0) + 1
+    _gen_pairs(sorted, results, current_rank, config)
+    _gen_triples(sorted, results, current_rank, config)
+    _gen_bombs(sorted, results, current_rank, config)
+    _gen_straights(sorted, results, current_rank, config)
+    _gen_rocket(sorted, results, current_rank, config)
+    if results.size() > MAX_ENUM_NODES:
+        results = results.slice(0, MAX_ENUM_NODES)
+    return results
+
+static func _gen_pairs(sorted: Array[Card], results: Array[HandEvaluator.EvaluatedPlay], current_rank: int, config: RuleConfig) -> void:
+    var rank_counts := {}
+    for c in sorted:
+        var rk := c.rank()
+        if not rank_counts.has(rk): rank_counts[rk] = []
+        rank_counts[rk].append(c)
+    for rk in rank_counts:
+        var cards: Array = rank_counts[rk]
+        if cards.size() >= 2:
+            var ep := HandEvaluator.evaluate(cards.slice(0, 2), current_rank, config)
+            if ep != null: results.append(ep)
+
+static func _gen_triples(sorted: Array[Card], results: Array[HandEvaluator.EvaluatedPlay], current_rank: int, config: RuleConfig) -> void:
+    var rank_counts := {}
+    for c in sorted:
+        var rk := c.rank()
+        if not rank_counts.has(rk): rank_counts[rk] = []
+        rank_counts[rk].append(c)
+    for rk in rank_counts:
+        var cards: Array = rank_counts[rk]
+        if cards.size() >= 3:
+            var ep := HandEvaluator.evaluate(cards.slice(0, 3), current_rank, config)
+            if ep != null: results.append(ep)
+            if cards.size() >= 3:
+                _gen_triple_plus_kickers(sorted, cards.slice(0, 3), results, current_rank, config)
+
+static func _gen_triple_plus_kickers(hand: Array[Card], triple: Array[Card], results: Array[HandEvaluator.EvaluatedPlay], current_rank: int, config: RuleConfig) -> void:
+    var remaining: Array[Card] = []
+    for c in hand:
+        if not _card_in(triple, c): remaining.append(c)
+    var pairs := _find_pairs(remaining)
+    for pair in pairs:
+        var ep := HandEvaluator.evaluate(triple + pair, current_rank, config)
+        if ep != null: results.append(ep)
+
+static func _gen_bombs(sorted: Array[Card], results: Array[HandEvaluator.EvaluatedPlay], current_rank: int, config: RuleConfig) -> void:
+    var rank_counts := {}
+    for c in sorted:
+        var rk := c.rank()
+        if not rank_counts.has(rk): rank_counts[rk] = []
+        rank_counts[rk].append(c)
+    for rk in rank_counts:
+        var cards: Array = rank_counts[rk]
+        if cards.size() >= 4:
+            var ep := HandEvaluator.evaluate(cards.slice(0, 4), current_rank, config)
+            if ep != null: results.append(ep)
+        for count in range(5, cards.size() + 1):
+            var ep := HandEvaluator.evaluate(cards.slice(0, count), current_rank, config)
+            if ep != null: results.append(ep)
+
+static func _gen_straights(sorted: Array[Card], results: Array[HandEvaluator.EvaluatedPlay], current_rank: int, config: RuleConfig) -> void:
+    var unique := _unique_ranks(sorted)
+    for start in unique:
+        for length in range(5, 13):
+            var needed: Array[int] = []
+            for r in range(start, start + length): needed.append(r)
+            var found := _pick_consecutive(sorted, needed)
+            if found.size() == length:
+                var ep := HandEvaluator.evaluate(found, current_rank, config)
+                if ep != null: results.append(ep)
+
+static func _gen_rocket(sorted: Array[Card], results: Array[HandEvaluator.EvaluatedPlay], current_rank: int, config: RuleConfig) -> void:
+    var sj_indices: Array[int] = []
+    var bj_indices: Array[int] = []
+    for i in range(sorted.size()):
+        if sorted[i].rank() == 15: sj_indices.append(i)
+        if sorted[i].rank() == 16: bj_indices.append(i)
+    if sj_indices.size() >= 2 and bj_indices.size() >= 2:
+        var cards: Array[Card] = []
+        for idx in sj_indices.slice(0, 2) + bj_indices.slice(0, 2):
+            cards.append(sorted[idx])
+        var ep := HandEvaluator.evaluate(cards, current_rank, config)
+        if ep != null: results.append(ep)
+
+static func _find_pairs(hand: Array[Card]) -> Array:
+    var result := []
+    var rank_groups := {}
+    for c in hand:
+        var rk := c.rank()
+        if not rank_groups.has(rk): rank_groups[rk] = []
+        rank_groups[rk].append(c)
+    for rk in rank_groups:
+        if rank_groups[rk].size() >= 2:
+            result.append(rank_groups[rk].slice(0, 2))
+    return result
+
+static func _card_in(cards: Array[Card], target: Card) -> bool:
+    for c in cards:
+        if c.card_id == target.card_id: return true
+    return false
+
+static func _unique_ranks(hand: Array[Card]) -> Array:
+    var seen := {}
+    var result: Array = []
+    for c in hand:
+        var rk := c.rank()
+        if not seen.has(rk):
+            seen[rk] = true
+            result.append(rk)
+    result.sort()
+    return result
+
+static func _pick_consecutive(hand: Array[Card], needed: Array[int]) -> Array[Card]:
+    var result: Array[Card] = []
+    var used := {}
+    for target in needed:
+        var found := false
+        for c in hand:
+            if c.rank() == target and not used.has(c.card_id):
+                result.append(c)
+                used[c.card_id] = true
+                found = true
+                break
+        if not found: return []
+    return result
+
+static func _contains_duplicate(results: Array[HandEvaluator.EvaluatedPlay], ep: HandEvaluator.EvaluatedPlay) -> bool:
+    for existing in results:
+        if existing.type == ep.type and existing.primary_rank == ep.primary_rank:
+            if existing.cards.size() == ep.cards.size():
+                return true
+    return false
+
+static func _sort(cards: Array[Card]) -> void:
+    cards.sort_custom(func(a: Card, b: Card): return a.compare_to(b) < 0)