The Dark Room is one of the game's three final stages, alongside its counterpart, The Chest, as well as The Void. The Dark Room is unlocked by defeating Satan 5 times, after which it can be accessed by touching the chest dropped by Satan with The Negative equipped. Entrance to the Dark Room can also be achieved via the I AM ERROR room on Sheol, even without The Negative as well as through the Black Market room on Sheol and through a trapdoor spawned by a button. After completing this level or the Chest for the first time, the Dark Room will always contain a large golden door in the first room, which can be unlocked with both Key Piece 1 and Key Piece 2 or Dad's Key, allowing access to Mega Satan.
The Dark Room can also be accessed by repeatedly using a Sacrifice Room. After Uriel and Gabriel are killed, continuing to use the Sacrifice Room will teleport Isaac to the Dark Room, regardless of what floor he was previously on.
The Dark Room also contains dirt mounds, which can be dug up using Mom's Shovel. Doing so for the first time will unlock The Forgotten. On subsequent runs, multiple dirt mounds can be found, and digging them up using We Need to Go Deeper!, an Ehwaz rune, or Mom's Shovel will spawn a random type of chest.
Like Sheol before it, the Dark Room consists of only one floor. In the Dark Room, it is not possible to bomb doors open to skip rooms. The Dark Room's rooms are mainly filled with bosses and mini-bosses. The boss of the floor is always The Lamb.
The first room you spawn in will automatically contain 4 Red Chests. Red Chests will also drop frequently upon clearing a room, regardless of whether the player has the Left Hand trinket or not. Additionally, all brown and golden chests spawned in the Dark Room will always contain Treasure Room items.
||Starts attached to the wall. After a while, it detaches, turning the room dark and chasing Isaac. Phases in and out of visibility when detached.|
| Black Maw
||When Isaac lines up with it horizontally, it charges in his direction and then doubles back, charging back to its original position. When Isaac is not horizontal to it, it spawns Leeches. Explodes when it dies.|
||Wanders around the room and throws a bone at Isaac when he is in sight.|
| Camillo Jr.
||Moves around the room diagonally, occasionally firing Technology lasers towards Isaac. Fires more often upon getting damaged.|
||Act like faster Frowning Gapers. When Isaac gets near, they phase in and out of visibility and pursue Isaac faster.|
||Slowly floats around the room, spawning several Attack Flies. Spawns Pooters upon taking damage. Spawns a Boom Fly upon death.|
||Disappears, then appears near Isaac and spits a cluster of spectral tears at him.|
| Red Ghost
||Disappears, then reappears near Isaac and fires a brimstone laser.|
||Slowly drifts towards Isaac, frequently firing 5 blood shots in quick succession towards Isaac. Tries to avoid Isaac's shots and occasionally teleports and reappears elsewhere.|
| Black Globin
||Chases Isaac, dealing a full heart of contact damage and spawning spiders whenever it takes damage. Spawns a spider, Black Globin's Head, and Black Globin's Body upon death.|
| Flesh Death's Head
||Moves diagonally around the room, dealing contact damage. Explodes into 6 blood shots in all directions upon death. Can be killed, but also dies when the room is cleared.|
| Scarred Double Vis
||Randomly wanders around the room. Pauses to charge and fire a Brimstone laser which fires from all four cardinal sides when Isaac gets in its line of sight.|
| Soul Sucker
||Flies slowly towards Isaac. Spawns a vortex that fires four Brimstone beams in the cardinal directions upon death.|
- If Isaac gets Key Piece 1 and Key Piece 2, the key will open the golden gate to fight Mega Satan, but if Isaac uses Forget Me Now, the floor will reset and Isaac won't get both Key Pieces back, making it so that the golden gate won't open again.
- The I AM ERROR room cannot be reached by any method in The Chest and the Dark Room.
The music for the Dark Room is titled Devoid, which means “empty”.
- The Dark Room is also the name of a room which, like its name suggests, is plunged into complete darkness, for the notable purpose of processing photos. The fact access to this floor is done by touching the chest in Sheol while holding The Negative, which is the name given to a photo which has not been processed yet and whose colours and hues are inverted, might be a nod to this.
- The layout to the Chest and to the Dark Room are identical for a given seed.
- The appearance of the Dark Room resembles Final Destination, a level that exists in every installment of the Smash Bros Games.
- One of the Super Secret Room layouts is of the Dark Room and a Black Heart. The sprite for the door is a portal rather than a gray door, however, due to the fact that bombed-out entrances in the Dark Room appear as portals.
- This secret room appears floating in a black void on most floors, but in the Dark Room it appears in a purple misty void instead, just like all the other rooms.
|Chapter 1||Chapter 2||Chapter 3||Chapter 4||Optional||Chapter 5||Chapter 6||Endgame|
|The Basement||The Caves||The Depths||The Womb|
|The Cellar||The Catacombs||Necropolis||Utero||???||The Void|
|Burning Basement||Flooded Caves||Dank Depths||Scarred Womb|
|The Basement||The Caves||The Depths||The Womb||Sheol||The Shop||Ultra Greed|
|The Binding of Isaac: Rebirth|
|Achievements||Attributes||Bosses||Cards and Runes||Challenges||Chapters|