Rat Key

Not to be confused with the Gnawed Key used to open the way to the Resourceful Rat's Lair, or the Rat Key Pickup used to open Rat Chests.

The Rat Key is a quest item in Exit the Gungeon. It is purchased from the Resourceful Rat in the Shop.

How to Obtain
The Rat Key is purchased from the Resourceful Rat in the Shop for 50 or 115.

The first Rat Key is given by the Resourceful Rat for free, however.

Use

 * Allows the player to unlock an imprisoned NPC later in the run.