Binding of Isaac: Rebirth Wiki

(in Repentance)

Red Key is an unlockable activated item added in The Binding of Isaac: Repentance.

Effects[ | ]

  • Allows Isaac to create a Red RoomRed Room by using it next to a wall where there would be no conditions that could prevent a room from spawning there (i.e., the same conditions for a Secret RoomSecret Room to spawn). This is indicated by red door outlines on walls.
  • These rooms are most commonly normal rooms, but have a 10% chance[1] to be a special room instead, even including Red Devil RoomDevil Rooms or Angel RoomAngel Rooms.
    • Red special rooms of any kind can appear in every floor.
  • These rooms use a special Red Room icon on the map.

Notes[ | ]

  • The types of special rooms that a Red RoomRed Room can be are the following:
  • All rooms made by Red Key will be 1x1 rooms that can have doors available on all sides.
  • All doors within a Red Room will be unlocked or opened, regardless of the room type they lead to. This can open Secret RoomSecret Rooms, and normally inaccessible Challenge RoomChallenge Rooms if they are adjacent to a Red Room. Red Room doors will also stay permanently open in the case of Challenge Rooms.
  • In HomeHome, Isaac can create a "Red Room" on the left side of the map right under Mom's room. This room will actually be a closet containing a non-tainted character's Tainted form.
    • If the respective Tainted character has already been found or a Tainted character is played, the room will contain Collectible Inner Child iconInner Child instead. If Inner Child has not been unlocked, the room will contain a ShopkeeperShopkeeper.
    • This can also be done by using a Cracked KeyCracked Key, which can be obtained through room drops or by leaving a trinket in a boss or item room and coming back to that room during the Ascent, and using it in the same spot.
  • If a door created by Red Key takes Isaac outside of the 13x13 area of the floor, he will be taken to the I AM ERRORI AM ERROR room.
    • The starting room of a floor is always in the center of the 13x13 area.
    • This does not occur in CorpseCorpse II, Dark RoomDark Room, ChestChest, The VoidThe Void, or the special version of MausoleumMausoleum / GehennaGehenna II containing Collectible Dad's Note iconDad's Note. No door outlines will appear at any boundary walls.
      • Additionally, this doesn't work during Red Redemption (challenge #44).
    • The I AM ERROR room door can only be created while already inside a Red Room. Normal rooms will not show the red outline if they are at the map's boundary.
  • Special Red Rooms can be versions that aren't normally encountered without a specific item or character.
  • Red Key can't overwrite Secret RoomSecret Rooms or Super Secret RoomSuper Secret Rooms. This can be used to discern their locations by finding walls that don't have red door outlines that would otherwise be valid Red Room spots.
  • Red Key can't create a room adjacent to the Boss RoomBoss Room on most floors, with some exceptions:
    • Red Key can create a room adjacent to Boss Hush ingameHush's room in the top right where the room that leads to The VoidThe Void usually generates. The door to this looks like a crack. This Red Room can only be created when Isaac is in another Red Room adjacent to it, i.e. from branching off one of the Treasure RoomTreasure Room.
      • Isaac can enter Hush's room from this crack, but going the other direction will lead him to the Entrance Portal room.
      • Isaac also can't create Red Rooms adjacent to the ShopShop on this floor either.
    • Red Key can create rooms adjacent to most Boss Rooms in The VoidThe Void, including Boss Delirium ingameDelirium's room. This can be used to find a Boss Room door leading to what would be an empty space (though this may find Boss Mr. Fred ingameMr. Fred instead).
    • Red Key can create rooms adjacent to the Boss RoomBoss Room in the Mirrored World of DownpourDownpour / DrossDross II.
  • When Isaac enters any Red Room adjacent to the Ultra Secret RoomUltra Secret Room, it immediately appears on the map along with the Secret Room jingle, and its door will automatically open.
  • If Isaac encounters a Red special room, all of its doors will be its special theme doors.
    • All doors in a Red Curse RoomCurse Room still feature spikes, which will damage Isaac if he decides to enter/exit.
    • A Red VaultVault's doors or a Red Dice RoomDice Room's doors each require two keys to open. The door where Isaac uses Red Key will be automatically unlocked, but the other doors remain locked until Isaac goes through them from inside or unlocks them from outside.
  • Multiple Red special rooms of the same type can spawn on one floor.
  • All Red Sacrifice RoomSacrifice Rooms will have their own independent use counters and rewards.
  • If Isaac has a teleport to a specific room (XVII - The StarsXVII - The Stars, IX - The HermitIX - The Hermit, Collectible Teleport 2.0 iconTeleport 2.0, etc.) and has created a special room such that there are multiple of a certain type on one floor, the teleport will choose randomly between each room.
  • It is possible to obtain Collectible Knife Piece 1 iconKnife Piece 1 outside of the intended method by spawning the Treasure RoomTreasure Room that contains it in DownpourDownpour / DrossDross.
    • Red Rooms in Downpour/Dross can contain White Fire Places as well.
  • Isaac is able to create Red Rooms in the Mirrored World of DownpourDownpour / DrossDross II. They will be reflections of the original floor's Red Rooms, and special rooms created in this way will still be empty.
  • Red Rooms can't be created around the Mine Cart RoomMine Cart Room of MinesMines / AshpitAshpit II.
    • Red Rooms on these floors can contain the yellow buttons used to build the mine cart track, however these ones do nothing.
  • Red Rooms in Chapter 3 can contain Marked Skulls even before the Ascent is unlocked.
  • When in Dark RoomDark Room or ChestChest, their spawn room containing their respective chests can be created by Red Key. These will function the same way regular chests of their respective type would on Dark Room/Chest outside the starting room.
    • New Mega Satan Head ingameMega Satan doors can't be found in these rooms.
  • Red Treasure RoomTreasure Rooms will be present in the Ascent, and will not replace regular Treasure RoomTreasure Rooms.
  • If a red Sacrifice RoomSacrifice Room appears in the Dark RoomDark Room and Isaac teleports via the 12th or higher sacrifice, Isaac will be sent back to the starting room without restarting the floor.
  • If a red Sacrifice RoomSacrifice Room appears in The VoidThe Void, then it is possible to defeat Boss The Lamb ingameThe Lamb after taking the path through ChestChest. This makes it possible to get up to 8 Completion Marks in the same run if playing quickly.
  • Red Key can be obtained by using Collectible Pandora's Box iconPandora's Box at HomeHome.

Synergies[ | ]

Interactions[ | ]

In-game Footage[ | ]

Trivia[ | ]

References[ | ]