Dungeon Delver's Guide

While attuned to this magic tome, you gain an expertise die to skill checks made to recognize and notice underground traps and architectural features. In addition, you gain an expertise die on saving throws against traps.

The book contains 10 illustrations of doors, 10 illustrations of traps, and 10 illustrations of monsters. As an action, you can permanently tear out an illustration and place it on a surface to make a real door, trap, or monster appear. Once an illustration is used, it can’t be used again.

If you place a door, a key that you can use to lock and unlock the door magically appears in your hand. Behind the door is a permanent passage through the wall. The passage is 5 feet wide, 8 feet tall, and up to 10 feet deep. The passage creates no instability. If you place a trap, you can choose between the following traps from this book (chapter 2): acid pit trap, commanding voice trap, explosive runes trap, false door trap, hidden pit trap (x3), lock trap (x3, can be placed only on a lock).

If you place a monster, the monster is not initially hostile to any creature present when it is summoned but is hostile to all other creatures. It otherwise acts according to its nature. The following monsters can be placed: black pudding , gelatinous cube , hell hound , kobold (x3), minotaur , skeleton immortal (x3, DDG).