Isaac can enter Hush's room from this crack, but going the other direction will lead him to the Entrance Portal room.

from branching off one of the Treasure Room. This Red Room can only be created when Isaac is in another Red Room adjacent to it, i.e.

Red Key can create a room adjacent to Hush's room in the top right where the room that leads to The Void usually generates.

Red Key can't create a room adjacent to the Boss Room on most floors, with some exceptions:.

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 overwrite Secret Rooms or Super Secret Rooms.

More Options' and Pay to Win's combined double item Treasure Rooms with a Shop Restock Machine.

Pay to Win's Shop Restock Machine Treasure Rooms.

More Options' double item Treasure Rooms.

Tainted Keeper's Shops, which can additionally contain items from the Boss and Treasure Room pools, and offer trinkets for sale.

Special Red Rooms can be versions that aren't normally encountered without a specific item or character.

Normal rooms will not show the red outline if they are at the map's boundary.

The I AM ERROR room door can only be created while already inside a Red Room.

Additionally, this doesn't work during Red Redemption (challenge #44).No door outlines will appear at any boundary walls. This does not occur in Corpse II, Dark Room, Chest, The Void, or the special version of Mausoleum / Gehenna II containing Dad's Note.The starting room of a floor is always in the center of the 13x13 area.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 ERROR room.This can also be done by using a Cracked 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 Inner Child has not been unlocked, the room will contain a Shopkeeper. If the respective Tainted character has already been found or a Tainted character is played, the room will contain Inner Child instead.

This room will actually be a closet containing a non-tainted character's Tainted form. In Home, Isaac can create a 'Red Room' on the left side of the map right under Mom's room.All rooms made by Red Key will be 1x1 rooms that can have doors available on all sides.

Serial keys to unlock world