briefly appears and teleports the sphere back to the top
of the s lope to begin the process again.
Initiative. The tra p acts on initiative count 10 (but see
the dynamic ele m ent be low).
Active Element. AJthough the trap is c omplex in n a-
ture, it has a single active element. That's all it nee ds.
Sphere of Crushing Doom (Initiative 10). T he trap's
active ele m ent is a sphere of steel tha t almost fills
the 10 -foot width of the hallway and rolls to the
bottom of the s lope on its turn. Each creature in
the sphere's path must ma ke a D C 20 Strength
saving throw. On a failed save, a creature takes 22
(4dl0) bludgeoning damage and is knoc ked prone.
On a successful save , a c reature ta kes half as much
damage and isn' t knocked prone. Objects that block
the sphere, such as a conjure d wall, take maximum
damage from t he impact.
Dynamic Element. The longer it rolls , the more lethal
the sphere becomes.
Speed Kills. After its turn, the sphe re gains s peed ,
represente d by its damage inc reasing by 11 (2d10).
While its damage is 55 (lOdlO) or greater, it acts on
initia tive count 20 and 10.
Countermeasures. The trap can be neutralized e ither
by stopping the sphere or preventing it from teleporting.
Stop the Sphere. Stopping the sphe re is the easiest
way to disrupt the trap. A wall of fo rce can do so
easily, as can a ny object placed in its path that has
e nough hit points to absorb damage from the sphere
without being destroye d.
Disrupt the Portals. Eithe r portal can be n eutralized
with three successful D C 20 Intelligence (Arcana)
c hecks, but the process of a na lyzing a portal to
disrupt it takes time. Faint runes in the ceiling and
floor a t both ends of the hallway are involved in the
functioning o f the portals. A c reature must firs t
use an action to examine a set of runes, the n use a
subsequent action to attempt to vandalize the runes.
Each successful check reduces the sphe re's damage
by 11 (2d10), as the disrupted sph e re loses s peed
moving through the failing portal.
AJternative ly, a set of runes can be disable d w ith
three s uccessful castings of dis pel m agic (DC 1 9)
targeting any of the runes in the set.
If the southern portal is destroye d , the sphere
s lams into the south wall and comes to a ha lt. It
blocks the door to the tomb, but th e characters
can escape.POISONE D TEMPEST
Complex trap (level 11 - 16, deadly threat)
This fiendis h trap was built to eliminate intrude rs who
infiltrate a yuan-ti temple. The trap is a room, 60 feet
on a side, with 5 -foot-wide stone doors in the middle of
each wall. In each corne r of the room stands a 10-foot-
tall s tatue of a great serpent, coiled and ready to strike.
The eyes in each statue are rubies worth 200 gp apiece.
Trigger. This trap activates when a ruby is prie d from
one of the statues. Each statue's mouth s lides open, re-
vealing a 1-foot-wide pipe that runs down its throat.
CHAPTER 2 1 DUNGEON MASTER'S TOOLSInitiative. The trap acts on initiative count 20 and ini-
tiative count 10.
Active Elements. The trap fills the room with poison
and other deadly effects.
Locked Doors (Initiative 20). The four doors to this
room slam shut and are locked in place by magic.
This effect activates only once, the firs t time the trap
is triggered.
Poison Gas (Initiative 20). Poison gas floods the
room. Each creature inside mus t ma ke a DC 20
Constitution saving throw, taking 33 (6d10) poison
damage on a faile d save, or half as muc h damage on
a successful one.
Tempest (Initiative 10). Air and gas boils from the
trap. Roll a d6, and cons ult the following table.TEMPEST EFFECTS
d62Effect
Hallucinatory gas scrambles the m ind and senses.
All Intelligence and Wisdom checks made in the
room have disadvantage until the Tempest element
activates again.
Explosive gas fills the area. If anyone holds an open
flame, it causes a n explos ion. All creatures in the
area must make a DC 20 Dexterity saving throw,
taking 22 (4d10) fire damage o n a failed save, or
half as much damage o n a successful one. The
flame is then extinguished.
3 Weakening gas fills t he room. All Strength and Dex-
terity checks made in the room have di sadvantage
until the Tempest element act ivates again.
4 Buffeting winds force each creature in the room to
succeed on a DC 20 Strength saving throw or be
knocked prone.
5 Smoke fills the room. Visibility is reduced to 1 foot
until the next time the Tempest element activates.
6 Poison floods the room, forcing creatures to make
saving throws as for the Po ison Gas element.Dynamic Element. The longe r the poison gas re-
mains in the room, the more letha l it becomes.
Increased Potency. T he damage from the Poison Gas
e le m ent increases by 11 (2d10) each round afte r it
activates , to a maximum of 55 (10d10).
Countermeasures. The re are a few ways that the trap
can be overcom e.
Open the Doors. Opening the doors is the quickest
way to ci rc umvent the trap, but they a re warde d with
magic. To open the doors , a character mus t firs t
succeed on a DC 20 Wisdom (Perception) c heck to
find the locking mech a nism. A s uccessful DC 20 In-
te lligence (Arcana) check is then r equire d to disable
the sphere of force that surrounds the lock (disp el
magic is ineffective against it). Success on a DC 20
Dexterity c heck using thieves' tools picks the lock.
Fina lly, a successful D C 20 Strength (Athle tics)
c heck is neede d to pus h th e door open. Each check
requires an action.