diff --git a/headers/enduro2d/high/gobject.hpp b/headers/enduro2d/high/gobject.hpp
index 7c43fed9..70fe1033 100644
--- a/headers/enduro2d/high/gobject.hpp
+++ b/headers/enduro2d/high/gobject.hpp
@@ -13,15 +13,21 @@ namespace e2d
     class gobject;
     using gobject_iptr = intrusive_ptr<gobject>;
     using const_gobject_iptr = intrusive_ptr<const gobject>;
+
+    class world_gobjects_ilist_tag;
+    using world_gobjects = intrusive_list<gobject, world_gobjects_ilist_tag>;
 }
 
 namespace e2d
 {
     class gobject final
         : private noncopyable
-        , public ref_counter<gobject> {
+        , public ref_counter<gobject>
+        , public intrusive_list_hook<world_gobjects_ilist_tag> {
     public:
         gobject(ecs::registry& registry);
+        gobject(ecs::registry& registry, const gobject& source);
+        gobject(ecs::registry& registry, const ecs::prototype& proto);
         ~gobject() noexcept;
     private:
         ecs::entity entity_;
diff --git a/headers/enduro2d/high/prefab.hpp b/headers/enduro2d/high/prefab.hpp
index 7514c6cc..0ab9e6bd 100644
--- a/headers/enduro2d/high/prefab.hpp
+++ b/headers/enduro2d/high/prefab.hpp
@@ -26,6 +26,13 @@ namespace e2d
 
         prefab& assign(prefab&& other) noexcept;
         prefab& assign(const prefab& other);
+
+        prefab& set_prototype(ecs::prototype&& proto) noexcept;
+        prefab& set_prototype(const ecs::prototype& proto);
+
+        const ecs::prototype& prototype() const noexcept;
+    private:
+        ecs::prototype prototype_;
     };
 
     void swap(prefab& l, prefab& r) noexcept;
diff --git a/headers/enduro2d/high/world.hpp b/headers/enduro2d/high/world.hpp
index eb4e4d22..b5541067 100644
--- a/headers/enduro2d/high/world.hpp
+++ b/headers/enduro2d/high/world.hpp
@@ -37,7 +37,9 @@ namespace e2d
 
         gobject_iptr instantiate();
         gobject_iptr instantiate(const prefab_asset::ptr& prefab);
+        gobject_iptr instantiate(const const_gobject_iptr& gobject);
     private:
         ecs::registry registry_;
+        world_gobjects gobjects_;
     };
 }
diff --git a/scripts/cloc_all.sh b/scripts/cloc_all.sh
index f6abdbd9..ab40e99e 100755
--- a/scripts/cloc_all.sh
+++ b/scripts/cloc_all.sh
@@ -2,6 +2,8 @@
 SCRIPT_DIR=`dirname "$BASH_SOURCE"`
 cloc \
   $SCRIPT_DIR/../headers/enduro2d \
+  $SCRIPT_DIR/../headers/3rdparty/ecs.hpp \
+  $SCRIPT_DIR/../headers/3rdparty/promise.hpp \
   $SCRIPT_DIR/../sources/enduro2d \
   $SCRIPT_DIR/../samples/sources \
   $SCRIPT_DIR/../untests/sources
diff --git a/scripts/cloc_engine.sh b/scripts/cloc_engine.sh
index 57b570c6..91c18f7b 100755
--- a/scripts/cloc_engine.sh
+++ b/scripts/cloc_engine.sh
@@ -2,4 +2,6 @@
 SCRIPT_DIR=`dirname "$BASH_SOURCE"`
 cloc \
   $SCRIPT_DIR/../headers/enduro2d \
+  $SCRIPT_DIR/../headers/3rdparty/ecs.hpp \
+  $SCRIPT_DIR/../headers/3rdparty/promise.hpp \
   $SCRIPT_DIR/../sources/enduro2d
diff --git a/scripts/cloc_headers.sh b/scripts/cloc_headers.sh
index beff52c2..a2e9aa29 100755
--- a/scripts/cloc_headers.sh
+++ b/scripts/cloc_headers.sh
@@ -1,3 +1,6 @@
 #!/bin/bash
 SCRIPT_DIR=`dirname "$BASH_SOURCE"`
-cloc $SCRIPT_DIR/../headers/enduro2d
+cloc \
+  $SCRIPT_DIR/../headers/enduro2d \
+  $SCRIPT_DIR/../headers/3rdparty/ecs.hpp \
+  $SCRIPT_DIR/../headers/3rdparty/promise.hpp \
diff --git a/sources/enduro2d/high/gobject.cpp b/sources/enduro2d/high/gobject.cpp
index 0686f87c..daba75e5 100644
--- a/sources/enduro2d/high/gobject.cpp
+++ b/sources/enduro2d/high/gobject.cpp
@@ -11,6 +11,12 @@ namespace e2d
     gobject::gobject(ecs::registry& registry)
     : entity_(registry.create_entity()) {}
 
+    gobject::gobject(ecs::registry& registry, const gobject& source)
+    : entity_(registry.create_entity(source.entity_)) {}
+
+    gobject::gobject(ecs::registry& registry, const ecs::prototype& proto)
+    : entity_(registry.create_entity(proto)) {}
+
     gobject::~gobject() noexcept {
         entity_.destroy();
     }
diff --git a/sources/enduro2d/high/prefab.cpp b/sources/enduro2d/high/prefab.cpp
index a25bb70d..b9a38004 100644
--- a/sources/enduro2d/high/prefab.cpp
+++ b/sources/enduro2d/high/prefab.cpp
@@ -28,11 +28,12 @@ namespace e2d
     }
 
     void prefab::clear() noexcept {
+        prototype_.clear();
     }
 
     void prefab::swap(prefab& other) noexcept {
         using std::swap;
-        E2D_UNUSED(other);
+        swap(prototype_, other.prototype_);
     }
 
     prefab& prefab::assign(prefab&& other) noexcept {
@@ -46,10 +47,25 @@ namespace e2d
     prefab& prefab::assign(const prefab& other) {
         if ( this != &other ) {
             prefab s;
+            s.prototype_ = other.prototype_;
             swap(s);
         }
         return *this;
     }
+
+    prefab& prefab::set_prototype(ecs::prototype&& proto) noexcept {
+        prototype_ = std::move(proto);
+        return *this;
+    }
+
+    prefab& prefab::set_prototype(const ecs::prototype& proto) {
+        prototype_ = proto;
+        return *this;
+    }
+
+    const ecs::prototype& prefab::prototype() const noexcept {
+        return prototype_;
+    }
 }
 
 namespace e2d
@@ -59,8 +75,7 @@ namespace e2d
     }
 
     bool operator==(const prefab& l, const prefab& r) noexcept {
-        E2D_UNUSED(l, r);
-        return true;
+        return l.prototype().empty() && r.prototype().empty();
     }
 
     bool operator!=(const prefab& l, const prefab& r) noexcept {
diff --git a/sources/enduro2d/high/world.cpp b/sources/enduro2d/high/world.cpp
index 0fe898e2..eaae757a 100644
--- a/sources/enduro2d/high/world.cpp
+++ b/sources/enduro2d/high/world.cpp
@@ -20,11 +20,27 @@ namespace e2d
     }
 
     gobject_iptr world::instantiate() {
-        return gobject_iptr(new gobject(registry_));
+        auto instance = gobject_iptr(new gobject(registry_));
+        intrusive_ptr_add_ref(instance.get());
+        gobjects_.push_back(*instance);
+        return instance;
     }
 
     gobject_iptr world::instantiate(const prefab_asset::ptr& prefab) {
-        E2D_UNUSED(prefab);
-        return instantiate();
+        auto instance = prefab
+            ? gobject_iptr(new gobject(registry_, prefab->content().prototype()))
+            : gobject_iptr(new gobject(registry_));
+        intrusive_ptr_add_ref(instance.get());
+        gobjects_.push_back(*instance);
+        return instance;
+    }
+
+    gobject_iptr world::instantiate(const const_gobject_iptr& source) {
+        auto instance = source
+            ? gobject_iptr(new gobject(registry_, *source))
+            : gobject_iptr(new gobject(registry_));
+        intrusive_ptr_add_ref(instance.get());
+        gobjects_.push_back(*instance);
+        return instance;
     }
 }