Binding of Isaac: Rebirth Wiki

Not to be confused with Satanic Bible Satanic Bible.

The Book of Belial is an activated item.


  • Gives +2 damage for the current room.
  • Removed in Afterbirth Guarantees the Devil Room Devil Room or Angel Room Angel Room to spawn after killing a boss while holding it.
  • Added in Afterbirth Increases the chance to open the Devil Room Devil Room or Angel Room Angel Room after killing a boss by 12.5% while holding it.
  • Added in Afterbirth † This item belongs to the Bookworm set. Collecting three items from this set will transform Isaac into Bookworm.


  • Judas Judas starts with this item by default.
  • Removed in Repentance The damage bonus does not stack with multiple uses in the same room or with XV - The Devil XV - The Devil.
    • Added in Repentance Additional uses in the same room or combined with XV - The Devil XV - The Devil give +1 damage per use.
  • While activated, switching items will end the bonus damage effect.
  • If the Added in Afterbirth †Schoolbag Schoolbag and a second activated item are held, the book must be equipped in the primary slot to receive the Devil Room Devil Room / Angel Room Angel Room bonus.
  • Removed in Afterbirth Only guarantees Devil/Angel Rooms on floors that they can normally appear on, and, unlike Goat Head Goat Head, picking up The Book of Belial after killing the boss will not open the Devil/Angel Room door.


Added in Repentance Judas' Birthright Combinations[]

While holding Birthright Birthright with Judas Judas or Dark Judas Dark Judas, Book of Belial is able to be held alongside another active item, similar to Book of Virtues Book of Virtues. The book's damage bonus is equal to (2/3) * number of charges the overlaid item took to use. Items that do not require charges to use do not grant a damage bonus unless there is an exception listed below.

Certain active items also gain additional effects, which are noted below; any items not listed have their standard effects aside from the temporary damage up Birthright gives them.

  • Alabaster Box Alabaster Box: Changes the payout to 2 Black Heart Black Hearts and 1 item from the Devil Room item pool. If a Devil Deal has been taken, the payout is boosted to 3 Black Hearts and 2 Devil items.
  • Bag of Crafting Bag of Crafting: Collecting Red Heart Red Hearts, Half Red Heart Half Red Hearts or Double Heart Double Hearts with this item has a chance to transform them into Black Heart Black Hearts. When a heart is transformed in this way, a special sound plays and a black smoke puff appears. Does not work with Scared Heart Scared Hearts.
  • Blood Rights Blood Rights: Invokes the effect of Razor Blade Razor Blade along with its original effect.
  • Book of Virtues Book of Virtues: Can be stacked along with Book of Belial, allowing you to carry 2 passive books and an activated item on top of them.
  • Clicker Clicker: Replaces the most recently acquired item with Pentagram Pentagram instead of removing it. Birthright's effects will also change to that of the character transformed into.
  • Damocles Damocles: The sword also gives Judas a +1.33 damage up while it's active.
  • Dark Arts Dark Arts: Allows gain of temporary damage ups when when using Dark Arts, similarly to Tainted Judas Tainted Judas.
  • Decap Attack Decap Attack: Grants Judas +2 damage and x3 tears fired per second while his head is detached from his body.
  • Forget Me Now Forget Me Now: Grants +2 damage up for the entirety of the new floor.
  • Genesis Genesis: Grants a free Pentagram Pentagram that will not be removed by Genesis.
  • Glass Cannon Glass Cannon: Grants Judas +2.67 damage up while Glass Cannon is broken.
  • Golden Razor Golden Razor: Also invokes the effect of Magic Fingers Magic Fingers when used; non-boss enemies killed by this effect also have a chance to drop 1-2 pennies.
  • Guppy's Paw Guppy's Paw: Grants a permanent 0.5 damage up for every converted heart.
  • How to Jump How to Jump: Enemies Judas jumps through take 2 + 0.2 * floor contact damage and are set on fire. The burn deals damage equal to Judas' damage, and ticks up to 5 times.
  • Isaac's Tears Isaac's Tears: Fires a ring of 10 tears instead of 8, and the tears deal 1.4 * Judas' damage, plus a flat 5.
  • IV Bag IV Bag: Gives a temporary +0.66 damage up with each use.
  • The Jar The Jar: Instead of dropping hearts on the floor, using The Jar consumes up to one full heart in the jar at a time, giving a temporary +0.66 damage up for each half heart consumed and spawning a puddle of red creep that deals 2 damage per tick (20 damage per second).
  • Jar of Wisps Jar of Wisps: Will only spawn Satanic Bible Satanic Bible wisps that increase Judas' Devil Room Devil Room chance by 10% for each one he has.
  • Kamikaze! Kamikaze!: Invokes the effect of The Necronomicon The Necronomicon effect along with the original effect.
  • Magic Fingers Magic Fingers: Also has a chance to invoke the effect of Golden Razor Golden Razor.
  • Magic Skin Magic Skin: Grants a permanent +0.5 damage up on use in addition to the temporary +4 damage up given to it by Birthright. This bonus is not lost if the broken hearts are removed.
  • Notched Axe Notched Axe: The axe receives a purplish glow and receives the following upgrades:
    • Increased durability: Each use of the axe has a very high chance not to use a charge.
    • Faster usage: The axe can be swung up to four times per second, regardless of Judas' tears stat.
    • Higher knockback: Enemies are knocked back when hit, receiving 8 + 0.2 * floor damage if they collide with a wall, obstacle, or other enemies.
    • Fire effect: The axe will set enemies on fire. The burn deals damage equal to Judas' damage, and ticks up to 5 times.
    • Increased luck: destroying obstacles with the axe has an increased chance to spawn pickups.
      • Destroying Poop Poops will spawn pickups much more frequently. When combined with Petrified Poop Petrified Poop, the chance becomes 100% and will often result in multiple pickups from a single poop.
      • Destroying Tinted Rocks will drop more consumables than usual, similarly to Super Special Rocks.
      • Destroying Props (such as Urns, Mushrooms, Skulls, and Polyps) gives the prop an extra chance to drop its rewards. This can result in a single prop giving multiple drops.
      • Destroying Fool's Gold rocks will drop significantly more coins.
  • Pandora's Box Pandora's Box: In addition to the item's expected reward, spawns one of the following demonic familiars: Blood Puppy Blood Puppy, Dark Bum Dark Bum, Demon Baby Demon Baby, Incubus Incubus, Lil Abaddon Lil Abaddon, Lil Brimstone Lil Brimstone, Succubus Succubus and Twisted Pair Twisted Pair.
  • Plan C Plan C: Respawns Judas as Dark Judas Dark Judas if he has an extra life.
  • Potato Peeler Potato Peeler: Each use grants a permanent +0.5 normal damage up in addition to a +0.2 flat damage up.
  • Razor Blade Razor Blade: Invokes the effect of The Necronomicon The Necronomicon effect along with the original effect.
  • Sacrificial Altar Sacrificial Altar: Grants +10.8 temporary damage up for every sacrificed familiar. The damage bonus scales down to 0 over time, similarly to Red Stew Red Stew. Sacrificing blue flies or blue spiders has no special effect.
  • Sharp Key Sharp Key: Invokes the effect of Razor Blade Razor Blade along with the original effect.
  • Stitches Stitches: Creates a shadowy line similar to Dark Arts Dark Arts between Judas and the familiar. Enemies caught in the line take damage equal to 2 * Judas' damage, plus a flat 3.
  • Urn of Souls Urn of Souls: The stream of fire is replaced with a controllable Brimstone Brimstone beam that destroys projectiles and deals more damage the longer it's active. The minimum damage is 2.25 + 0.24 * floor, and the maximum damage is 2.8 + 0.3 * floor, which it scales up to over the course of 3 seconds of continuous fire.
    • Souls dropped from enemies are colored red, and the Urn displays a red graphic on the HUD when active.
  • Vade Retro Vade Retro: Instead of exploding on the spot, souls home in on nearby enemies and explode on contact, similarly to Purgatory Purgatory. The souls deal 2 * Judas's damage up to 3 times and destroy projectiles.
  • Wavy Cap Wavy Cap: Gives a permanent damage bonus equal to 0.2 * the maximum number of times Wavy Cap's effects have been stacked.

In-game Footage[]



  • Can still open Angel Room Angel Rooms even though it is a Satanic book.
  • It is one of the four books in the Satanic Bible.
  • Belial is a name used for Satan Satan in some Jewish and Christian texts.
  • Added in Repentance This item is used in Bloody Mary (Challenge #37).
  • Added in Repentance The previously unused item ID 59 is now occupied by the active/passive version of Book of Belial, which is obtained when Judas Judas or Dark Judas Dark Judas has Birthright Birthright.
  • Added in Repentance The effect of Notched Axe with Judas Judas' and Dark Judas Dark Judas' Birthright is a reference to Minecraft's enchanting mechanic.
    • All of its upgrades are based on existing Minecraft enchantments - Unbreaking, Fire Aspect, Knockback, Efficiency and Fortune.
    • However, Fire Aspect and Knockback normally cannot be applied to pickaxes in Minecraft, making it an odd choice for Notched Axe to have these buffs.



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