The Book of Belial

*Not to be confused with .*

**The Book of Belial** is an activated item.

## Effects

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

## Notes

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

## Synergies

* : Causes The Book of Belial to apply a 1.5x damage multiplier on top of its normal effect. This multiplier cannot stack with multipliers from  or .
* : Spawns black and red wisps in the middle ring. Wisps deal double damage compared to normal wisps.
* : Gives +3 damage for the current room.

## Judas' Birthright Combinations

While holding  with  Judas or  Dark Judas, Book of Belial is able to be held alongside another active item, similarly to . The book provides +0.66 damage for each charge of the held item. 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.

* : Changes the payout to 2 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.
* : Collecting Red Hearts, Half Red Hearts or Double Hearts with this item has a chance to transform them into 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 Hearts.
* : Invokes the effect of  along with its original effect.
* : Can be stacked along with Book of Belial, allowing you to carry 2 passive books and an activate item on top of them.
* : Judas leaves a damaging flame trail while the invincibility is active instead of creating beams of light. Blocking damage just as the invincibility begins deals heavy damage to all enemies in the room and grants Judas a temporary damage bonus.
* : Replaces the most recently acquired item with  instead of removing it. Birthright's effects will also change to that of the character transformed into.
* : The sword also increases Judas' damage by x1.4 then a flat +1 while it's active.
* : Grants temporary damage ups for every enemy/projectile hit by Dark Arts, similarly to  Tainted Judas. This stacks with  Dark Judas' inherent version of this, doubling the amount of damage gained.
* : Grants Judas +2 damage and x3 tears fired per second while his head is detached from his body.
* : Grants +2 damage up for the entirety of the new floor.
* : Grants a free  that will not be removed by Genesis.
* : Grants Judas +2.67 damage up while Glass Cannon is broken.
* : Also invokes the effect of  when used, which occurs after the damage increase and deals an additional +5 damage; non-boss enemies killed by this effect also have a chance to drop 1-2 pennies.
* : Grants a permanent 0.5 damage up for every converted heart.
* : 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.
* : Fires a ring of 10 tears instead of 8, the tears are piercing and spectral, and the tears deal 1.4 \* Judas' damage, plus a flat 5.
* : Gives a temporary +0.66 damage up with each use.
* : 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).
* : Will only spawn  wisps that increase Judas' Devil Room chance by 10% for each one he has.
* : Invokes the effect of  effect along with the original effect.
* : Also has a chance to invoke the effect of .
* : 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.
* : 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 Poops will spawn pickups much more frequently. When combined with , 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.
* : In addition to the item's expected reward, spawns one of the following demonic familiars: , , , , , , , or .
* : Respawns Judas as  Dark Judas if he has an extra life.
* : Each use grants a permanent +0.5 normal damage up in addition to a +0.2 flat damage up.
* : Invokes the effect of  effect along with the original effect.
* : Grants +10.8 temporary damage up for every sacrificed familiar. The damage bonus scales down to 0 over time, similarly to . Sacrificing blue flies or blue spiders has no special effect.
* : Invokes the effect of  without dealing damage to Judas along with the original effect.
* : Creates a shadowy line similar to  between Judas and the familiar. Enemies caught in the line take damage equal to 2 \* Judas' damage, plus a flat 3.
* : The stream of fire is replaced with a controllable  beam that destroys projectiles and deals more damage the longer it's active. The minimum damage is *3.37 + 0.361 \* floor*, and the maximum damage is *4.2 + 0.45 \* 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.
* : Instead of exploding on the spot, souls home in on nearby enemies and explode on contact, similarly to . The souls deal 2 \* Judas's damage up to 3 times and destroy projectiles.
* : Gives a damage bonus which lasts until the next floor equal to 0.2 \* the maximum number of times Wavy Cap's effects have been stacked.

## Gallery

* Book of Belial when activated.
* Unused image for use animation. This sprite is closer to the one used in the original game.
* 3DS The icon of the Book of Belial as seen on the lower 3DS screen.

## Trivia

* This item also increases the odds of getting an 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 in some Jewish and Christian texts.
* This item is used in Bloody Mary (Challenge #37).
* The previously unused item ID `59` is now occupied by the active/passive version of Book of Belial, which is obtained when  Judas or  Dark Judas has .
	+ Despite this, this version of the item is not obtainable by other characters. If you use  on an item pedestal of item ID `60`, , it'll skip to .
* The effect of Notched Axe with  Judas' and 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.