Book of Secrets is an unlockable active item in The Binding of Isaac.

Activates one of the following map effects: Treasure Map, The Compass or Blue Map, for the duration of the current floor.

Highlights any tinted rocks and rocks with a crawl space in the room.

Cannot give effects that are already activated via any means.

If all of the effects are already active, it will provide X-Ray Vision for the current floor, opening all secret room entrances.

If used on a floor with Curse of the Lost active, it will immediately grant the X-Ray Vision effect.

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.

Defeat Satan as Eden.

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

Book of Secrets can be found in the following item pools:

The following tags are applied to this item:

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

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

Below is the Internal Item Description as shown in-game.
Note that some stat changes are not displayed here. Please see the main description for the full effects.

Book of Secrets

• Grants an effect that reveals new information on the map
• May reveal the map layout, special room icons, or secret room locations
• Abyss: x1 locust .5x Isaac's damage
• Book of Virtues: x1 middle wisp - 2 hp - 3 damage
• Book of Virtues: Cracked Orb effect on death

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