diff --git a/README.md b/README.md
index 5287b99..5f18265 100644
--- a/README.md
+++ b/README.md
@@ -16,5 +16,10 @@ see test-game/manifest.setage
   * [x] `input` provides case insensitive input checking
   * [x] `exact input` provides exact input checking
   * [x] `item check`, `item take` provides item checking
-* [ ] combining items and other item interactions
-* [ ] 
+* [x] combining items and other item interactions
+  * [x] basic
+  * [x] multiple outputs
+  * [x] lockable
+    * [x] "item" = examine an item
+    * [x] "room" = enter a room
+    * [x] "interactable" = use an interactable
diff --git a/docs.toml b/docs.toml
index a892605..a05a8b0 100644
--- a/docs.toml
+++ b/docs.toml
@@ -30,6 +30,20 @@ item.examine = "message when the `item` is examined" # `item` can be any item id
 item.hidden = false # optional, default.
 
 
+[recipes.recipeid] # Optional
+ingredients = ["itemid1", "itemid2", ...] # Required
+# --
+result_id = "itemid" # Required
+result_text = "shorttext of the result item" # Required
+# OR
+result_ids = ["id1", "id2", ...] # Required
+result_texts = ["text1", "text2", ...] # Required; short texts of the items
+# --
+text = "message when items get combined with this recipe" # Optional; default = "> You combined items."
+lock = "" # Optional; one of: item, room, interactable
+lock_target = "id" # Optional; of the lock above
+
+
 [rooms.id] # Required, id can be any other room id.
 description = "description of the room as it appears in the listing of exits from other rooms"
 examine = "description of the room when you examine it"
diff --git a/setage.py b/setage.py
index c17c73f..ce66580 100755
--- a/setage.py
+++ b/setage.py
@@ -88,6 +88,8 @@ class SetageShell(Cmd):
     intro = ""
     prompt = "> "
     ruler = "~"
+    interacted_with = set()
+    rooms_been_in = set()
 
     def cmdloop(self, intro=None):
         print(self.intro)
@@ -273,6 +275,7 @@ class SetageShell(Cmd):
                       f"invalid `type` '{inter["type"]}' "
                       f"in interactable '{arg}'")
             if can_activate:
+                self.interacted_with.add(arg)
                 if "target_room" not in inter:
                     target_room = current_room_id
                 else:
@@ -434,6 +437,7 @@ class SetageShell(Cmd):
                 print(rooms[current_room_id]["go"])
             else:
                 print(f"You went {arg}.")
+            self.rooms_been_in.add(current_room_id)
         else:
             print("> I can't go there...")
         return self.check_win()
@@ -501,6 +505,48 @@ class SetageShell(Cmd):
         """Check your inventory."""
         self.do_inventory(arg)
 
+    def do_combine(self, arg):
+        """Combine items: combine item1,item2"""
+        recipes = manifest["recipes"]
+        items = [a.strip() for a in arg.split(",")]
+        if len(items) < 2:
+            print("> Not enough items to combine...")
+            return
+        for item in items:
+            if item not in inventory:
+                print(f"> {item} not in inventory...")
+                return
+        for recipe in recipes.items():
+            rec = recipe[1]
+            can = True
+            if rec["lock"]:
+                can = False
+                if rec["lock"] == "item":
+                    if rec["lock_target"] in inventory:
+                        can = True
+                elif rec["lock"] == "interactable":
+                    if rec["lock_target"] in self.interacted_with:
+                        can = True
+                elif rec["lock"] == "room":
+                    if rec["lock_target"] in self.rooms_been_in:
+                        can = True
+                else:
+                    print(f"ERROR: Invalid lock type for recipe `{recipe[0]}`")
+                    return True
+            if can:
+                # FIXME: multiple recipes with same ingredients???
+                if set(items) == set(rec["ingredients"]):
+                    print(rec["text"])
+                    for item in items:
+                        inventory.pop(item)
+                    if "result_ids" in rec:
+                        for idx, _id in enumerate(rec["result_ids"]):
+                            inventory[_id] = rec["result_texts"][idx]
+                    else:
+                        inventory[rec["result_id"]] = rec["result_text"]
+                    return self.check_win()
+        print("> I can't combine these...")
+
     def do_credits(self, arg):
         """Print credits."""
         if "credits" not in metadata:
diff --git a/test-game/manifest.setage b/test-game/manifest.setage
index 1acded8..d68450d 100644
--- a/test-game/manifest.setage
+++ b/test-game/manifest.setage
@@ -29,6 +29,19 @@ detergent.examine = "A bottle of detergent. Half-filled. Stinks."
 shiny.examine = "A heart-shaped shiny locket with a picture of a horse inside."
 shiny.hidden = true
 note.examine = "The note reads: there is a [shiny] hidden in one of the rooms of this house."
+stone.examine = "Ston. Rok."
+stick.examine = "stiC"
+weapon.examine = "wpn"
+trash.examine = "trasshhhhhhhhhhhhh"
+
+
+[recipes.weapon]
+text = "ooja booja"
+lock = "item"
+lock_target = "note"
+ingredients = ["stone", "stick"]
+result_ids = ["weapon", "trash"]
+result_texts = ["a weapon", "trsh"]
 
 
 [rooms.1]
@@ -37,6 +50,8 @@ go = "You walk into a room full of trash, garbage and other junk."
 examine = "This room doesn't have much to it, just a lot of dust, old wood trash and a couple torn paintings. This room stinks!"
 
 [rooms.1.items]
+stone = "Ston. RoK."
+stick = "stiC"
 
 [rooms.1.interactables.lever]
 name = "a rustic lever"
@@ -95,4 +110,4 @@ examine = "The room has yellowed wallpapers. They stink of old age. There's a fa
 note = "a torn, yellowed note"
 
 [rooms.4.exits]
-up = "1"
\ No newline at end of file
+up = "1"