The Book of Belial is an active item in The Binding of Isaac.

While held +12.5% chance for a devil/angel deal.

On use +2 damage for the current room.

Multiple uses will only add +1 damage.

Passive variant If Judas or Black Judas obtain Birthright, they receive a special variation of The Book of Belial that can be held alongside another active item, similar to Book of Virtues. This variant synergizes differently with certain active items. For more details, check the synergies section on active item pages.

The special variant won't always grant +2 damage on use, but will instead use a formula for calculating the damage: NumberOfCharges × 0.66.

The above formula will result in +2 damage for active items with 3 charges, just like The Book of Belial itself.

Timed-charge items and items with no charges will not grant a damage bonus, unless they have a specific synergy.

This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this item for the previous Repentance version, check this page instead.

This item contributes towards the Bookworm transformation. Collecting 3 items from this set will make Isaac fire an extra tear 25% of the time.

The Book of Belial can be found in the following item pools:

The following tags are applied to this item:

The following special synergies and interactions for The Book of Belial have been documented.

* Note that not all possible synergies and interactions are listed here.

• Check out the item description on the external Isaac Wiki.