A Key (Japanese: カギKey) is an item that can be used to unlock doors in dungeons in the Pokémon Mystery Dungeon series. They are generally rare and difficult to obtain, usually appearing in later dungeons as a random floor item, or bought from Kecleon Shops.
A key to open a red door. It disappears once you open a door.
List of items found in chambers
Pokémon Mystery Dungeon: Red Rescue Team and Blue Rescue Team
In Pokémon Mystery Dungeon: Red Rescue Team and Blue Rescue Team, the Key is used to open chambers appearing on set floors of certain dungeons in order to gain rare items that are usually otherwise unobtainable, such as HMs, Friend Bows and Wish Stones. It is consumed after use.