Binding of Isaac: Rebirth Wiki

(in Repentance)
This article is about the trinket that creates Blue Womb rooms. For the trinket that opens the Hush fight and empowers Pandora's Box, see Strange Key.

Blue Key is an unlockable trinket added in The Binding of Isaac: Repentance.

Effects[ | ]

  • Entering a room that requires a KeyKey does not consume a key, but brings Isaac to a room resembling ??????, which acts as an in-between of the two rooms.
    • These rooms contain assortments of Blue GaperBlue Gapers, Blue BoilBlue Boils, and/or Blue Conjoined FattyBlue Conjoined Fatties, and are always long rooms (either normal or slim). They have a chance to give a reward when cleared, like normal rooms.
    • Once exited, the room cannot be re-entered.

Notes[ | ]

  • Doors that were unlocked with the trinket have a blue hue emitting from them instead of the normal floor-dependent hue.
  • The doors leading to the entrance of DownpourDownpour or DrossDross can be unlocked for free by Blue Key, though the blue room generated will be a dead end. Leaving the way Isaac came in will leave the door unlocked, allowing the player to continue normally.
  • Rooms that require money to enter (ArcadeArcades or rooms affected by Collectible Pay To Play iconPay To Play) can also be opened for free.
  • Doors that require two keys to open, such as VaultVaults or Dice RoomDice Rooms, will be opened instantly instead of waiting for the animation of both keys to be used.
  • The door leading to Boss Hush ingameHush will also produce a blue room, despite not requiring a key.
  • Isaac can unlock the rooms with Blue Key, but not enter them straight away. By exiting and re-entering the room, he can pass through the door that was unlocked with the Blue Key without having to go through the room in between.

Synergies[ | ]

  • Door StopDoor Stop / Collectible Mercurius iconMercurius: The blue room can be exited without fighting the enemies, and the door will remain unlocked.

Interactions[ | ]

  • Broken PadlockBroken Padlock: Doors opened via explosions will not spawn the corridor.
  • Collectible Ventricle Razor iconVentricle Razor: Any portals inside the hall will be deleted upon exiting. While in the hallway, any portals to the outside can still be taken.

In-game Footage[ | ]

Trivia[ | ]

  • The trinket might be a reference to SCP-860, a fictional key that acts in a near-identical manner.
  • If used on the ?????? floor, one might hear the mid-combat layer of the floor's theme, Nativitate, an asset which was previously unused.

Bugs[ | ]

Bug Bug! If used with The Forgotten and Birthright, leaving The Forgotten's body in the hallway will cause it to reappear next to you when you exit, but upon switching back to the body, it will become immobile, and switching back to the soul will make it immobile too, causing a softlock requiring you to exit then continue the run.
Bug Bug! Opening a locked door without entering it and then leaving and re-entering the room will no longer cause the door opened by Blue Key to lead to a Blue Womb room. In other words, this removes the downside of the trinket.