D12

D12 is an unlockable activated item added in The Binding of Isaac: Afterbirth.

Effect

Re-rolls obstacles in the current room into other random obstacles.
- Poops, TNT, Fire Places and Key Blocks cannot be re-rolled.
Obstacles can reroll into: Rocks, Tinted rocks, Cobwebs, Chapter-specific obstacles (Urns, Mushrooms, Skulls, and Polyps), Metal Blocks, Trap doors, Crawl Spaces, TNT, White Poop, Fool's Gold Rocks, Reward Plates and Killswitches
These obstacles will only reroll into another one in this group: Poops, Retractable Spikes, Normal and Red Fire Places, both types of TNT, and Cobwebs.
- These obstacles can also reroll into Reward Plates and Killswitches, but will not reroll any further. They can not roll into Trap doors or Crawl Spaces.

Notes

Destroyed obstacles will not be rerolled.
Rainbow Poop, Golden Poop, Tinted Rocks, Trap Doors, Crawl Spaces , Fool's Gold and Killswitches are much less likely to be created by the D12 than all other obstacles.
It is possible to reroll the spikes in a Sacrifice Room and render the room unusable.
- Newly created spikes (but not retractable spikes) in Sacrifice Rooms use separate reward counters, allowing you to get more rewards in one room.
Each re-roll is seeded and will produce the same result for each room that the D12 is used in.

Synergies

Lucky Rock, Meconium, Petrified Poop, and Stud Finder can provide extra value in conjunction with their associated obstacles.
Leo / Mega Mush / Notched Axe / Pyro / Stompy / Sulfuric Acid / Terra / Thunder Thighs can provide Isaac a way to destroy the re-rolled obstacles.
Car Battery: Re-rolls have a higher chance of entering the looping pool and creating obstacles that can't reroll ( Reward Plates, Killswitches, Trap doors and Crawl Spaces)
Book of Virtues: Spawns blue die wisps on the middle ring. Wisps' tears have a 5% chance to reroll obstacles they hit. Poops and TNT barrels cannot be rerolled.
XVI - The Tower? / A Card Against Humanity: Created obstacles can be rerolled into more useful objects such as Rainbow Poop or Golden Poop. Rocks created from XVI - The Tower? will have a larger pool to pick from.

Interactions

Car Battery: Re-rolls twice instantly without any benefits.

In-game Footage

Gallery

Splash image which appears when D12 is activated.

Trivia

The D12 is the only way in the game to remove metal blocks.
- Metal blocks can also be destroyed with Mega Mush.
White Poop isn't in the looping pool despite being a poop.
The original Antibirth mod had its own D12 that functioned similarly to this item. For obvious reasons, that item wasn't added in Repentance, although the D12's effect was updated in V1.7.8 to be more similar to the Antibirth version.
- In Antibirth, the pick up quote was Reroll your playground.

Bugs

Bug!	Using D12 while Tainted Forgotten is sitting over a pit (not being thrown) will make his head and weapon disappear, rendering him unable to attack and preventing Tainted Soul from picking him up, unless the room is left or the run is exited and resumed. This can easily cause a soft-lock.

Bug!	If D12 creates a trap door in The Void, Chest, Dark Room or Home it will restart the floor when entered. If a trap door is created on Corpse II, it will take Isaac to ???. ( XVI - The Tower? is needed on stages without rocks.)

Bug!

If creates a

Reward Plate in the boss room on the floor where an alt door is allowed to appear (After is unlocked), activating the button to create enemies and kill will create another one, up to 4 doors (depending on the size of the room). Exiting the boss room will leave only the original alt door. By entering a copy of the door, you can go to the alt floor and if you exit, the original door will also be open, even if you did not open it.

Bug!

When rerolling obstacles while Isaac has ; any

Movable TNT or

Fire Places spawned in the fear radius has a chance of being spawned momentarily feared with only the purple tint to indicate the status effect. This effect lasts even on the remains of either object after it's destroyed before the fear effect ends. Corn poops created in the radius are unaffected; however, the

Eternal Fly may also become temporarily feared. has the same bug with the only difference being that it is charming obstacles and

Eternal Flies and turning them pink

Bug!	If Isaac has Car Battery and uses D12 two times or more in a quick succession (possible with The Battery), some obstacles may become stacked (there will be two or more obstacles in the same spot).