Effect. When activated, this trap casts a sleep spell centered on the pressure plate, using a 9th-
level spell slot.
Countermeasures. A successful DC 20 Wisdom (Perception) check reveals the pressure plate. A
successful DC 20 Intelligence (Arcana) check made within 5 feet of the pressure plate disables
the trap, and a check with a total of 10 or lower triggers it. A successful dispel magic (DC 19)
cast on the pressure plate destroys the trap.
Designing Simple Traps
You can create your own simple traps by using the following guidelines. You can also adapt the
example traps for different levels and severity of threat by modifying their DCs and damage
values as shown below.
Purpose
Before diving into the details of your trap, think about its reason for being. Why would someone
build such a trap? What is its purpose? Consider the trap’s creator (in the adventure), the
creator’s purpose, and the location the trap protects. Traps have context in the world — they
aren’t created for no reason — and that context drives the trap’s nature and effects.
Described below are a few of the general purposes a trap might have. Use them to inspire the
creation of your own traps.
Alarm. An alarm trap is designed to alert an area’s occupants of intruders. It might cause a bell
or a gong to sound. This type of trap rarely involves a saving throw, because the alarm can’t be
avoided when the trap goes off.
Delay. Some traps are designed to slow down enemies, giving a dungeon’s inhabitants time to
mount a defense or flee. The hidden pit is a classic example of this kind of trap. A 10-foot-deep
pit usually deals little damage and is easy to escape, but it serves its purpose by impeding
intruders. Other examples of delaying traps include collapsing walls, a portcullis that drops from
the ceiling, and a locking mechanism that shuts and bars a door. If a delaying trap has moving
parts that directly threaten characters when they operate, the characters are usually required to
make Dexterity saving throws to avoid harm.
Restrain. A restraining trap tries to keep its victims in place, leaving them unable to move. Such
traps are often employed in conjunction with regular guard patrols, so that victims are
periodically extricated and taken away to be dealt with. But in an ancient dungeon, the guards
might be long gone.
Restraining traps usually require a successful Strength saving throw to be avoided, but some
don’t allow saving throws. In addition to dealing damage, a restraining trap also renders a
creature unable to move. Making a subsequent successful Strength check (using the trap’s saving
throw DC) or dealing damage against the trap can break it and free the captive. Examples include
a bear trap, a cage that drops from a ceiling, and a device that flings a net.