Backdoor Room Key

The Backdoor Room Key looks nothing like the hotel key: it is a golden, old-fashioned key with a rounded ring at the top, and it is the variant that opens the locked doors of The Backdoor. Its job is the same as the Hotel Room Key's, unlocking the next door in line, and a player can carry only one at a time.

Finding it

The first room of The Backdoor, numbered -51, always holds a room key on the exact same table. After that, keys spawn inside the room that is locked. In rooms with unnumbered doors, they can appear inside the small rooms behind those doors, and the wiki warns players to be careful of the Vacuum while searching them.

The floor's guide is Curious Light rather than Guiding Light. It still makes a shiny sound near a key, but it does not highlight keys the way Guiding Light does, so listening matters more here.

Small differences

Since The Mines update, a normal key can be used while the other hand holds an item, but the wiki notes that this does not apply to the Backdoor key. Its icon leaked before the floor was released, and its model, like the Retro Key's, is a reference to an old yellowish key unlike the ones in The Hotel.