Blue Key

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

Effects

 * Entering a room that requires a key 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 Gapers, Blue Boils, and/or Blue 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.

Synergies

 * Door Stop/: The blue room can be exited without fighting the enemies, and the door will remain unlocked.

Trivia

 * The trinket is most likely a reference to SCP-860, a fictional key that acts in a near-identical manner.