Gungeon Blueprint

 is a passive item.

Effects

 * Fully maps out every subsequent floor.
 * Reveals all secret rooms.

Trivia

 * This item is linked to Woban, the character mentioned in the Ammonomicon entry for the Cartographer's Ring. It is implied that Woban created the Gungeon Blueprint as an ultimate revenge against the Gungeon after the walls of the Gungeon began shifting.
 * The Gungeon Blueprint's pickup quote references how the Gungeon is procedurally generated ingame.