diff --git a/app/ecs/ecs.js b/app/ecs/ecs.js
index dcda2b9..a17f7ae 100644
--- a/app/ecs/ecs.js
+++ b/app/ecs/ecs.js
@@ -204,8 +204,23 @@ export default class Ecs {
       return entityIds;
     }
     const creating = {};
+    const extendedSpecificsList = [];
     for (let i = 0; i < specificsList.length; i++) {
-      const [entityId, components] = specificsList[i];
+      const [entityId, rawComponents] = specificsList[i];
+      let {
+        $$extends,
+        ...components
+      } = rawComponents;
+      if ($$extends) {
+        components = {
+          ...this.readJson($$extends),
+          ...components,
+        };
+      }
+      extendedSpecificsList.push([entityId, components]);
+    }
+    for (let i = 0; i < extendedSpecificsList.length; i++) {
+      const [entityId, components] = extendedSpecificsList[i];
       if (!this.$$detached.has(entityId)) {
         this.deferredChanges[entityId] = [];
       }
@@ -227,8 +242,8 @@ export default class Ecs {
     for (const i in creating) {
       this.Components[i].createMany(creating[i])
     }
-    for (let i = 0; i < specificsList.length; i++) {
-      const [entityId, components] = specificsList[i];
+    for (let i = 0; i < extendedSpecificsList.length; i++) {
+      const [entityId, components] = extendedSpecificsList[i];
       this.rebuild(entityId, () => Object.keys(components));
       if (this.$$detached.has(entityId)) {
         continue;