Judas is a character unlocked after beating
Satan for the first time. He starts with one Red Heart container, 3
coins, and
The Book of Belial. Judas also has a 1.35× damage multiplier.
Black Judas
When a character dies while having
Judas' Shadow in their inventory, they will respawn as Black Judas. Black Judas spawns with two
Black Hearts, a damage multiplier of 2.00×, and a base speed of 1.1. Black Judas has the highest damage multiplier of all the playable characters.
Black Judas can still gain Red Heart containers despite starting with none.
Black Judas cannot gain Red Heart containers; items that grant Red Heart containers (including empty ones) will give him the same amount of
Black Hearts instead.
Black Judas is considered by the game to be a separate character from Judas, but Black Judas
counts as Judas for the achievements and unlocks that require Judas, including his Completion Marks. He will also receive
Tainted Judas' bonus effects when using 
Dark Arts.
Notes
- The
The Book of Belial's damage increase is very powerful; it should be kept, if possible, until the player has enough damage from other sources.
The Book of Belial also guarantees a
Devil Room or
Angel Room to open after defeating a boss while holding it.
The Book of Belial increases the chance by 12.5% instead of guaranteeing one.
- Due to Judas' low starting health, health upgrades should be prioritized.
Devil Room deals can also be risky, if not unaffordable.
Item Interactions

Birthright:
The Book of Belial becomes a passive item that can be held beneath other active items, similar to 
Book of Virtues. The The Book of Belial's damage boost scales with the amount of charges the active item above it has.
- The damage boost may not work with single-use items, unlimited use items, timed recharges, or items that do not follow normal room charge rules (
Isaac's Tears, etc). It also has special interactions with certain items — see The Book of Belial for more information.
- Stacks with Book of Virtues.
- If Judas is not currently holding The Book of Belial, he receives it.
Blood of the Martyr: Synergizes with The Book of Belial for an extra 1.5× damage multiplier.
Gallery
Judas' appearance while The Book of Belial is active.
Judas' appearance while The Book of Belial is active.
Judas' transition screen portrait.
Black Judas' transition screen portrait.
Judas' locked character icon.
Trivia
- Judas appeared in the original Binding of Isaac, where he was unlocked by beating
Womb for the first time.
- Judas is a reference to Judas Iscariot, the Twelfth Disciple of Jesus Christ. Judas betrayed Jesus to the Romans in exchange for thirty pieces of silver, represented by the three coins Judas starts the game with. Moreover, the coins are also believed to represent the three Abrahamic faiths, Judaism, Christianity, and Islam.
- Contrary to popular belief, Judas' fez is not a reference to the game Fez, created by Phil Fish. Edmund McMillen has stated that the initial statement was a joke and that he used the fez due to it being easily recognizable.
- When reviving using Judas' Shadow, entering a miniboss fight will refer to the player as "Black Judas".
- Judas' locked character icon is a locked box with his fez placed on it.
References