Devil Rooms either contain a set of different Pickups or allow him to make deals with the devil. A Devil Room has a chance to appear in a Boss Room after the Boss occupying it has been defeated. If certain criteria are met, a Devil Room can be replaced by an Angel Room.
In Greed Mode, Devil Rooms appear upon completing the optional 11th wave of a floor.
- 1-3 Deals with the Devil
- 3 Red Chests
- 2 Black Hearts
- 2 Deals with the Devil and 1 Devil Beggar
- 4 Deals with the Devil
- 5 Red Chests
- 3 Devil Beggars
- 2 Runes
Additionally, 2 Red Fireplaces may spawn. Spikes may spawn instead of or in addition to any items/pickups.
Mom's Hands, Nulls, and Imps may also appear in the Devil Room.
Urns may spawn in the Devil Room.
If a Devil Room appears upon defeating Mom's Heart or It Lives, it will only contain a trapdoor to Sheol.
Devil Rooms that appear upon defeating It Lives no longer contain trapdoors and instead have normal Devil Room contents.
Deals with the Devil
A Devil Room has a high chance of spawning Collectibles that will be put up for sale. Unlike shops where Isaac pays with money, to make deals with the devil Isaac has to trade heart containers for the items on sale. All items either cost 1 or 2 red heart containers and their prices roughly correspond to their power.
See the following item pools for a comprehensive list of items offered and their health price:
- Devil Room (Item Pool)
- Devil Room (Afterbirth Item Pool) and Devil Room (Greed Mode Item Pool)
- Devil Room (Afterbirth+ Item Pool) and Devil Room (Afterbirth+ Greed Mode Item Pool)
- If Isaac does not have any red hearts or red heart containers upon entering a Devil Room, all items will cost 3 Soul Hearts.
- Taking a Devil Deal that costs an equal or greater amount of red heart containers than Isaac possesses while also possessing one or more Soul Hearts or Black Hearts will leave Isaac with only those Soul Hearts or Black Hearts and will not kill him.
- If taking a deal leaves you with no heart containers, you can still survive if you pick up a soul heart or black heart while Isaac is holding the item in the air.
- If Isaac is presented with 2+ items to buy, but only have enough red hearts to buy one, the price of the other(s) will change to 3 soul hearts upon spending your red hearts.
- Refusing to make deals with the devil will give Isaac the chance of an Angel Room replacing the Devil Room on subsequent floors. If any deal with the devil is taken (including Black Market deals), Angel Rooms will not spawn for the remainder of the run.
- Only paying health (Red Hearts or Soul Hearts) for an item in a Devil Room or a Black Market counts as a deal with the devil. Taking black hearts, opening Red Chests, and taking items that weren't paid for (such as Red Chests, Krampus, Beggars, Pandora's Box, and Credit Card) do not count as Devil Deals, allowing Isaac to still see Angel Rooms.
Conditions to make Devil Rooms appear
A Devil Room can only open on floors between Basement/Cellar II and Womb/Utero II.
There is only a 1% base chance for the Devil Room door to open. This chance can be modified in various ways:
|Blowing up one dead shopkeeper on the current floor||+10%|
|Having a second Pentagram||+10%|
|Having Black Candle||+30%|
|Holding Book Of Revelations||+35%|
|Destroying one normal Beggar on the current floor||+35%|
|Taking no red heart damage against the boss||+35%|
|Taking no red heart damage for the entire floor||+99%|
|Holding Book Of Belial||+2500%|
|Having Goat Head||Guaranteed|
|Previous Devil Room Door seen two floors ago||x0.5|
|Previous Devil Room Door seen less than two floors ago||x0.25|
- On XL floors, the Devil Room Door can only appear after completing the second boss room.
- Once a Devil Room Door closes for the floor, it cannot be re-opened without picking up Goat Head.
- Taking soul or black heart damage does not decrease the chance to open a Devil Room; only red hearts count.
- Taking red heart damage from a Devil Beggar, Blood Donation Machine, IV Bag, Blood Rights, or Razor Blade does not decrease the chance to open a Devil Room. (The Bad Trip pill effect still counts as red heart damage, though.)
- Killing Devil Beggars, Skull Game Beggars, or Key Masters do not increase the chance to open the Devil Room.
- If a Devil Room Door spawns after a boss fight, it is recommended to go directly into the Devil Room, as the chance for the door to stay open upon leaving and re-entering the room is 1/4th of the original opening chance.
There are also additional ways to enter a Devil Room on any floor:
- Red Chests have a chance of teleporting Isaac into the Devil Room upon being opened.
- Using the Joker Card to directly transport into the room.
- Using Teleport 2.0 after all other rooms on the floor (excluding the I AM ERROR room) have been visited.
- If the game process crashes or is forcefully closed, the Devil Room of the current floor will be changed to a Devil Room with 2 deals. Guppy's Head and The Book Of Sin will usually be available unless Isaac has already seen them.
- The rock behind the Devil can rarely be a Tinted Rock.
- An angel statue can rarely substitute the Satan statue, and can be awoken with an explosion.
- Angels spawned in this way do not drop Key Pieces.
- In the original Binding Of Isaac, the devil rooms are a bit harder, because if you have a Eternal Heart, it will remove it if you make a trade, so you have to pick up the heart after you make the trade.
Boss Challenge Room
Super Secret Room
I AM ERROR