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Leng Spider

Leng spiders are intelligent, carnivorous spiders. Adults have a leg span of 20 to 30 feet or occasionally more, but smaller (younger) specimens are common. Adults weigh 1 to 3 tons. Since they never stop growing, a few are far larger.

Leng spiders are sly and design traps for their prey, which can be elaborate and often involve treasure as bait.

They are clever enough to let some adventurers live after finding the treasure, in order to entice further visitors to their mountain lairs. The creatures thrive on being underestimated: they delight in preying on humanoid egos and spring traps when a would-be treasure-seeker is most confident.

Leng spiders have a complex, territorial society that reacts violently to any who infringe on their territory. Unless guarding their homes, they rarely fight to the death and will retreat if severely wounded.

Web Traps

Leng spiders are particularly gifted at crafting complex traps using their webs and other objects at hand. Often these traps utilize bait in the form of wounded captives or attractive treasure. Creating a trap takes a Leng spider a number of hours equal to the final trap’s calculated Challenge. The trap created must be mechanical (not magical) in nature, and often utilizes Leng spider webbing. Leng spider traps must be frequently tended and often need minor repairs, and as such, a single Leng spider can only maintain a few traps at a time.

If your game awards noncombat experience for traps, a Leng spider should generally maintain a total number of traps at a time whose challenge ratings add up to less than the Leng spider’s own Challenge. For practical access, all of these traps are typically located within 1 mile of each other. Leng spiders prefer traps that catch and incapacitate rather than kill. Three typical Leng spider traps are presented below.

Boulder-Capped Pit Mechanical Trap

Challenge: 6 (2,300 XP)

When a creature touches a trigger object, a 5-foot-wide, 20-foot-deep pit opens underneath, causing the creature to fall into the pit below, supported by elaborately engineered webbing. A concealed boulder nearby then falls to seal the hole so that the spider can collect the intruder as part of a routine patrol, hoisting away the boulder with cleverly engineered webbing. A successful DC 15 Wisdom (Perception) check discerns that the trigger item (usually a piece of treasure) is conspicuously untouched and laced with a strand of webbing so fine as to be nearly invisible. A successful DC 15 Intelligence (Investigation) check is necessary to confirm that the trapped section of floor is actually the cover of a pit or to deduce that a patch of ceiling or wall nearby is a silk image hiding a boulder strung up by ultra-strong webbing. Unless a character succeeds at a DC 20 Dexterity check with thieves’ tools or weaver’s tools, disturbing the webbing causes the boulder to roll on a straight path to the trigger object’s original location.

Triggering the trap requires all creatures present to roll initiative after the pit opens. The trap rolls initiative with a +8 bonus. When the trap is triggered, all creatures in the affected area fall into the pit, taking 7 (2d6) bludgeoning damage from the fall. The pit’s floor and walls are coated in the Leng spider’s Toxic Web. Whenever a creature starts its turn restrained by the webbing, it must succeed on a DC 17 Constitution saving throw or be poisoned. At the end of each of the poisoned creature’s turns, it makes a new saving throw, ending this poisoned condition on itself on a success. On the trap’s initiative count on the round after it is triggered, a 6-foot-diameter solid stone sphere falls atop the pit, blocking the opening with no more than an inch gap at any point around the edge. If the boulder passes through a creature’s space, the creature must succeed on a DC 15 Dexterity saving throw or take 55 (10d10) bludgeoning damage and be knocked prone.

The boulder weighs 10 tons. It can also be attacked and destroyed (AC 17; damage threshold 10; hp 1,000; resistance to cold, fire, lightning, and slashing damage; immunity to poison and psychic damage). The boulder can also be broken with 6 person-hours of work with mason’s tools, picks, or other suitable equipment. If the boulder is broken by any means while atop the pit, it collapses into the pit and each creature within must make a DC 15 Dexterity saving throw, taking 55 (10d10) bludgeoning damage and becoming restrained on a failed save, or taking half as much damage and not becoming restrained on a successful one. A restrained creature can be freed as an action with a successful DC 20 Strength check. The Leng spider can use its webbing as cables to roll the boulder aside as an action. Characters who carefully inspect the webbing can deduce how to manipulate the webbing to move the boulder themselves with a successful DC 25 Intelligence (Investigation) check or a successful DC 20 Dexterity check with weaver’s tools.

Boulder Pendulum Mechanical Trap

Challenge: 8 (3,900 XP)

A boulder pendulum is typically placed in a confined area, such as along a mountain ledge or in a narrow passage with a tall ceiling. When triggered, a large boulder swings down on a thick cord of webbing, passing through a 30-foot line to the trigger location.

A successful DC 15 Wisdom (Perception) check notices a strand of webbing so fine as to be nearly invisible that serves as the trigger. A successful DC 15 Intelligence (Investigation) check deduces that a patch of ceiling or wall nearby is a silk image hiding a boulder strung up by ultra-strong webbing. Unless a character succeeds at a DC 18 Dexterity check with thieves’ tools or weaver’s tools, disturbing the webbing triggers the trap.

The swinging boulder makes a melee attack with a +8 bonus against each target in its path. On a hit, the target takes 45 (10d8) bludgeoning damage and must succeed on a DC 15 Dexterity saving throw or be knocked prone. If the creature was on a ledge no wider than its space, it falls off the ledge if it failed its saving throw by 5 or more.

Web Net Mechanical Trap

Challenge: 2 (450 XP) if encountered with Leng spiders

This trap uses a silk trip wire to release a net of fine poisonous webbing suspended from the ceiling.

The trip wire is 3 inches off the ground and stretches between two columns or trees. The net is hidden by cobwebs or foliage. A successful Wisdom (Perception) check DC 15 spots the fine silk trip wire and net. A successful DC 15 Dexterity check using thieves’ tools breaks the trip wire harmlessly. A character without thieves’ tools can attempt this check with disadvantage using any edged weapon or edged tool. On a failed check, the trap triggers.

When the trap is triggered, the web is released, covering a 10-foot-square area. Those in the area are trapped under the web and restrained, and those that fail a DC 10 Strength saving throw are also knocked prone. Whenever a creature starts its turn restrained by the webbing, it must succeed on a DC 17 Constitution saving throw or be poisoned. At the end of each of the poisoned creature’s turns, it makes a new saving throw, ending this poisoned condition on itself on a success. A creature can use its action to make a DC 10 Strength check, freeing itself or another creature within its reach on a success. The net has AC 10 and 20 hit points. Dealing 5 slashing damage to the net (AC 13) destroys a 5-foot-square section of it, freeing any creature trapped in that section.