Page 118 - DnD 5e - Xanathar's Guide to Everything

characters notice it. After that, they can simply walk
TRIGGERS
A trigger is the circumstance that needs to take place to around it, or they can climb down one side, walk across
activate the trap. the bottom of the pit, and climb up the other side.
Decide what causes the trap to activate and determine Once you determine how a trap can be disarmed or
how the characters can find the trigger. Here are some avoided, decide the appropriate ability a nd skill com-
binations that characters can use. A Dexterity check
example triggers:
us ing thieves' tools, a Strength (Athletics) check, and an
A pressure plate that, when it is stepped on, acti- Intelligence (Arcana) check are all commonly used for
vates the trap this purpose .
• A trip wire that springs a trap when it is broken, usu- A Dexterity check using thieves' tools can apply to any
ally when someone walks through it trap that has a mechanical element. Thieves' tools can
• A doorknob that activates a trap when it is turned be used to disable a trip w ire or a pressure plate, disas-
the wrong way semble a poison needle mechanism, or clog a valve that
• A door or chest that triggers a trap when it is opened
leaks poisonous gas into a room.
A trigger usually needs to be hidden to be effective. Oth- A Strength check is often the method for thwarting
erwise, avoiding the trap is usually easy. traps that can be destroyed or prevented from operating
A trigger requires a Wisdom (Perception) check if through the use of brute force. A scything blade can be
s imply spotting it reveals its nature. The characters can broken, a s liding block can be held in place, or a net can
foi l a pit trap hidden by a leaf-covered net if they s pot the be torn apart.
pit through a gap in the leaves. A trip wire is foiled if it is A magic trap can be disabled by someone who can
spotted, as is a pressure plate. undermine the magic used to power it. Typically, a suc-
Other traps require careful inspection and deduction cessfu l Intelligence (Arcana) check enables a character
to notice. A doorknob opens a door when turned to the to figure out how a magic trap functions and how to ne-
left, but activates a trap when turned to the right. Such a gate its effect. For instance, the character could discover
subtle trap requires a successful Intelligence (Investiga- that a statue that belches a jet of magical flame can be
tion) check to notice. The trigger is obvious. Understand- disabled by s hattering one of its glass eyes.
ing its nature is not. Once you k now what kind of check is called for, you
The DC of the check, regardless of its type, depends then determine what happens on a failed attempt to dis-
on the s kill and care taken to conceal the trap. Most able the trap. Depending on the kind of check involved
traps can be detected with a successful DC 20 check, and the nature of the trap, you might determine that any
but a crudely made or hastily built trap has a DC of 15. failed check has negative consequences- usually involv-
Exceptionally devious traps might have a DC of 25. ing the triggering of the trap. At other times, you could
You must then put some thought into what the char- assign a number that the check must exceed to prevent
acters learn with a successful check. In most cases, the the trap from going off. If the total of the check is equal
check reveals the trap. In other cases, it uncovers clues, to or lower than that number, the trap activates.
but foiling the trap still requires some deduction. The
characters might succeed on the check but still trigger PLACING A SIMPLE TRAP
the trap if they don't unders tand what they have learned. Context and environment a re critical when it comes
to properly locating a trap. A swinging log trap that's
EFFECTS meant to knock characters aside is a mere inconve-
Designing a trap's effects is a straightforward process. nience on a typical forest path, where it can be easily
The tables for saving throw DCs, attack bonuses, dam- circumvented. But it's a potentially deadly hazard on a
age, and the like give you a starting point for most sim- narrow trail that hugs the s ide of a towering cliff face.
ple traps that deal damage. Choke points and narrow passages that lead to im-
For traps with more complex effects, your best s tart- portant places in a dungeon a re good spots for traps,
ing point is to use the Spell Equivalent by Level table to especially those that serve as alarms or restraints. The
find the best match for your trap's intended effect. Spells goal is to foil or delay intruders before they can reach a
are a good starting point because they are compact critical location, giving the dungeon's denizens a chance
pieces of game design that deliver specific effects. to mount a defense or a counterattack.
If you are us ing a spell as a starting point, check to see A treasure chest, a door leading to a vault, or any other
if you need to tweak its effects to fit the trap's nature. For obstacle 'or container that bars the way to a valuable
instance, you can easily change the damage type a spell treasure is the ideal location for a slaying trap. In s uch
delivers or the saving throw it requires. instances, the trap is the last line of defense against a
thief or intruder.
DISARMING A SIMPLE TRAP Alarm traps, since they pose no direct physical
Only one successful ability check is required to disarm threat, are appropriate for areas that are also used by
a s imple trap. Imagine how your trap operates, and then a dungeon's denizens-assuming the residents know
think about how the characters could overcome it. More about the trap and how to avoid setting it off. Accidents
than one kind of ability check might be possible. S ome can happen, but if a goblin stumbles inside its den and
traps are so poorly concealed that they can be discov- activates an alarm trap, there's no real harm done. The
ered or circumvented without active effort. For instance, alarm sounds, the guards arrive, they punish the clumsy
a hidden pit trap is effectively disarmed as soon as the goblin, and they reset the trap.

CHAPTER 2 I DUNC EON MASTER'S TOOLS