Items with this tag grant the Bookworm transformation.
|Anarchist Cookbook||5.100.65||Summon bombs||Spawns six Troll Bombs around the room.||1|
|Book of Revelations||5.100.78||Reusable soul protection||Gives one Soul Heart, increases the chance for a Devil Room or Angel Room, and changes the boss of the current floor to a Harbinger if possible.||3|
|Book of Secrets||5.100.287||Tome of knowledge||Gives the effect of Treasure Map, The Compass, or Blue Map for the duration of the current floor.||0|
|Book of Shadows||5.100.58||Temporary invincibility||Creates a protective shield, nullifying all types of damage in the current room for 10 seconds.||2|
|How to Jump||5.100.282||It's time you learned how||Upon use, Isaac jumps in the direction he is currently moving, allowing travel over obstacles and enemies.||1|
|Monster Manual||5.100.123||Temporary buddy generator|| Spawns a familiar from a specific selection for the current room.
Spawns a familiar from a specific selection for the current floor.
|Satanic Bible||5.100.292||Reusable evil... but at what cost?||Gives one Black Heart. Replaces the boss room item on the current floor with a Devil Deal.||4|
|Telepathy for Dummies||5.100.192||Temporary psychic shot||Gives homing tears for the current room. Also gives +3 range.||0|
|The Bible||5.100.33||Temporary flight||On use, Isaac gains flight for the current room. Instantly kills Mom, Mom's Heart, and It Lives when activated, but kills Isaac when used on Satan.||1|
|The Book of Belial||5.100.34||Temporary DMG up||+2 damage for the current room.
Guarantees a Devil Room or Angel Room will be open after beating a boss while holding it. Increases the chance by 12.5%.
|The Book of Sin||5.100.97||Reusable item generator||Generates a random pickup, pill, card, or rune.||2|
|The Necronomicon||5.100.35||Mass room damage||Deals 40 damage to every enemy in the room.||1|
|Book of the Dead||5.100.545||Rise from the grave||Upon use, creates a friendly Bony, Black Bony, or an orbital bone for each enemy killed in the current room.
Can also create a friendly Bone Fly or Revenant.
|Book of Virtues||5.100.584||Spiritual companionship||On use, spawns a destroyable orbiting Wisp familiar that fires tears and deals contact damage. Also acts as a passive item that causes other active items to spawn themed Wisps.||3|
|Lemegeton||5.100.712||Item summoner||Spawns a wisp representing a random passive item, which orbits Isaac but can be destroyed. While the wisp is alive, Isaac gains that item's effects. The item wisp generated depends on the item pool of the room Isaac is currently in.||3|