For the non-consumable, functionally identical accessory, see Skeleton Key.
Metal Keys are an item dropped from numerous NPCs, as well as found in most levels which contain a locked gate.
Metal Keys are an item which are held in the players hand. When attempting to enter a locked gate with a Metal Key in one's hands, it will consume the key and unlock the gate.
Metal Keys are not specific to any door; a player can bring a key through different levels and open an entirely different locked gate with it.
The Skeleton Key functions identically to a Metal Key, with the exception that it can be used to open an infinite amount of doors and is a passive item rather than a held item.
There are multiple situations where a Metal Key may spawn:
- In Yang's inventory. Stunning him, killing him, or delivering two Cave Turkeys will cause him to drop it. This key is intended to open his cave containing treasure.
- In any Shopkeeper's inventory, if their shop spawned with a basement or attic, protected by a locked gate. This key can only be obtained by stunning or killing them.
- In any location in The Jungle, Volcana, or Tide Pool containing a single locked door. The key will be found in an open sub area, and its spawn will guarantee the spawn of another chunk containing a locked door with some treasure and typically crates within.
- In Madame Tusk's inventory. The only way to obtain this key is to kill her. This key is intended to either open the locked door to the room containing The Tusk Idol in Tide Pool, or to open the vault door in her Palace of Pleasure in 6-3 of Neo Babylon.
- Killing Waddler will drop a metal key. This metal key is not necessarily intended for any door.
Note that for the "Air of Oppression" Level Feeling, no metal keys will spawn on the level, meaning that the player will have to either bomb their way into, or use a Skeleton Key to access the many locked cells of the area.