diff --git a/game/data/schemas/level_table.gd b/game/data/schemas/level_table.gd
index d9aea353..4d66fbc1 100644
--- a/game/data/schemas/level_table.gd
+++ b/game/data/schemas/level_table.gd
@@ -48,10 +48,24 @@ func validate() -> Array:
 # ④ 无环（出边目标深度严格大于源）。良构＝句柄唯一·出边全命中·type 在五类枚举·battle/boss 带深度。
 # 入口/终点个数与参数档的一致性归产出侧（关卡节点图生成 v1.1），本处不核个数；商店位归冒烟断言把关，本处禁检。
 static func validate_graph(nodes: Array) -> Array:
-	var errs: Array[Dictionary] = []
 	if nodes.is_empty():
-		errs.append({"category": "structural", "message": "图节点集为空"})
-		return errs
+		return [{"category": "structural", "message": "图节点集为空"}]
+	var well := _check_nodes_wellformed(nodes)
+	if not (well["errs"] as Array).is_empty():
+		return well["errs"]
+	var by_id: Dictionary = well["by_id"]
+	var edges := _check_edges(by_id, well["indeg"])
+	if not (edges["errs"] as Array).is_empty():
+		return edges["errs"]
+	var stops := _check_terminals(by_id, edges["outs"], edges["indeg"])
+	if not (stops["errs"] as Array).is_empty():
+		return stops["errs"]
+	return _check_reachability(by_id, edges["outs"], stops["entries"], stops["terminals"])
+
+
+# 良构基底：字段齐·type 在枚举·深度非负·句柄唯一（返回 by_id 与入度骨架供后续检复用）
+static func _check_nodes_wellformed(nodes: Array) -> Dictionary:
+	var errs: Array[Dictionary] = []
 	var by_id := {}
 	var indeg := {}
 	for i in nodes.size():
@@ -73,8 +87,12 @@ static func validate_graph(nodes: Array) -> Array:
 		by_id[nid] = node
 		if not indeg.has(nid):
 			indeg[nid] = 0
-	if not errs.is_empty():
-		return errs
+	return {"errs": errs, "by_id": by_id, "indeg": indeg}
+
+
+# 出边良构＋无环判据（④）：目标句柄存在、目标深度严格大于源；同时产出去边表与入度计数
+static func _check_edges(by_id: Dictionary, indeg: Dictionary) -> Dictionary:
+	var errs: Array[Dictionary] = []
 	var outs := {}
 	for nid in by_id.keys():
 		outs[nid] = []
@@ -87,25 +105,34 @@ static func validate_graph(nodes: Array) -> Array:
 				errs.append({"category": "structural", "message": "连线 %d→%d 违反前进方向（目标深度须严格大于源）" % [nid, int(tid)]})
 			outs[nid].append(int(tid))
 			indeg[int(tid)] = int(indeg[int(tid)]) + 1
-	if not errs.is_empty():
-		return errs
+	return {"errs": errs, "outs": outs, "indeg": indeg}
+
+
+# 检①＋检③：入口（无入边）≥1、终点（无出边）≥1、终点恒为 Boss 且 Boss 无出边
+static func _check_terminals(by_id: Dictionary, outs: Dictionary, indeg: Dictionary) -> Dictionary:
+	var errs: Array[Dictionary] = []
 	var entries := []
 	var terminals := []
 	for nid in by_id.keys():
 		if int(indeg[nid]) == 0:
 			entries.append(nid)
-		if (outs[nid] as Array).is_empty():
-			terminals.append(nid)
-			if String(by_id[nid]["type"]) != "boss":
-				errs.append({"category": "structural", "message": "终点 %d 非 Boss（终点恒为 Boss）" % nid})
-		elif String(by_id[nid]["type"]) == "boss":
-			errs.append({"category": "structural", "message": "Boss 节点 %d 带出边（终点不可外出）" % nid})
+		if not (outs[nid] as Array).is_empty():
+			if String(by_id[nid]["type"]) == "boss":
+				errs.append({"category": "structural", "message": "Boss 节点 %d 带出边（终点不可外出）" % nid})
+			continue
+		terminals.append(nid)
+		if String(by_id[nid]["type"]) != "boss":
+			errs.append({"category": "structural", "message": "终点 %d 非 Boss（终点恒为 Boss）" % nid})
 	if entries.is_empty():
 		errs.append({"category": "structural", "message": "入口节点数 = 0（须 ≥1）"})
 	if terminals.is_empty():
 		errs.append({"category": "structural", "message": "终点节点数 = 0（须 ≥1）"})
-	if not errs.is_empty():
-		return errs
+	return {"errs": errs, "entries": entries, "terminals": terminals}
+
+
+# 检②：全部节点从某入口可达且可达某终点（无孤儿、无断头）
+static func _check_reachability(by_id: Dictionary, outs: Dictionary, entries: Array, terminals: Array) -> Array:
+	var errs: Array[Dictionary] = []
 	var from_entry := {}
 	for eid in entries:
 		_mark_reachable(int(eid), outs, from_entry)