IED antigrain warhead trap

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IED antigrain warhead trap

IED antigrain warhead trap

An antimatter-powered antigrain warhead connected to a trigger which detonates on touch or bullet impact. Since it is hidden in the surrounding terrain, it cannot be placed adjacent to other traps. Animals can sense these when calm.

Base Stats

Market Value
1205 Silver [Note]
2 kg


1 × 1
Terrain Affordance


Required Research
Skill Required
Construction 3
Work To Make
1,400 ticks (23.33 secs)
Resources to make
Antigrain warhead 1
Destroy yield

The IED antigrain warhead trap is Security building that explodes when stepped on, detonating in a massive explosion powerful enough to instantly kill all enemies in-game except for the Thrumbo, Centipede, and shield belt-wearing enemies.


IED antigrain warhead traps can be constructed once the Ieds project has been researched. Each trap requires Antigrain warhead 1 Antigrain warhead, 1,400 ticks (23.33 secs) of work and a Construction skill of 3.


Traps are single use security buildings that may be triggered when a pawn of any kind walks over it.

  • The base trigger chance is 100% for enemies, including mechanoids and animals affected by the manhunter mental state. Note that despite the name, animals currently hunting a human pawn for food are not "manhunters" and are not considered enemies.
  • Non-manhunting wild animals have a 25% chance to trigger the trap.
  • Colonists and tame animals have 0.4% (one in 250) chance to trigger the trap.[Friendly Mechanoids?]
  • Friendly visitors and their animals will never trigger a trap.

However, colonists and non-manhunting animals are aware of the location of traps, and will avoid pathing over them if reasonably practical.[Path Cost?] One notable exception is roped animals being dragged by a handler - the rope limits their movement, overriding their usual behavior.

Prisoners are considered to be their original faction for the purposes of traps. Enemy who you have taken prisoner will retain their 100% trap trigger rate and will ignore traps when pathfinding. Colonists that you have taken prisoner retain their 0.4% trap trigger rate, even during a prison break, and will avoid traps whenever possible.

In all instances, the nimble trait multiplies the trigger chance for that pawn by 10%, that is, a 10% chance for enemies and 0.04% chance for friendly pawns.
IEDs can also be triggered when hit by a projectile dealing the Bullet, Arrow, or ArrowHighVelocity damage type, or when damaged below 20% of their maximum HP.

When triggered, the trap will begin to spark and emit a hissing sound for 15 ticks (0.25 secs) before exploding, dealing "Bomb Super" damage in a 15 tile radius of itself, dealing 550 damage at the center and 110 damage at the extreme edge of the radius and linearly interpolated in between, and setting fires to roughly 22% of the affected tiles.

Nearby non-drafted pawns, colonists and NPC alike, will attempt to clear the blast radius once the spark starts however the short wick time and large radius make success unlikely.


Radius of where buildings will wake mechs is highlighted in red.

Regular antigrain warheads are already accurate, due to their massive blast radius. Antigrain shells have a radius of 14.9 tiles, and a mortar has a base miss radius of 9 tiles. A launched warhead can hit the intended tile and every tile within a 5-tile radius, with a force stronger than a doomsday rocket launcher, with 100% certainty. This makes antigrain traps more niche than regular IED traps.

Antigrain traps have the advantage of being placed in a precise location. Bulkier mechs like centipedes are able to survive the edge of an antigrain shell, but not the center. The trap can provide a more precise, and thus, more powerful, blast against these targets.

Great against stationary threats like crashed ship parts and mech clustersContent added by the Royalty DLC without proximity activators. They will let you place down a trap nearby - so long as it isn't too close to a mech/structure.

Good against mechanoid commandersContent added by the Biotech DLC, such as the apocriton. Whenever a mech boss is summoned, all of its escorts will follow the boss, rather than rushing ahead like with regular mech raids.

Finally, the antigrain shell must actually be fired from a mortar, forcing players to lead their shots against moving targets. Therefore, the trap can help prevent some human error, if you know exactly where raiders will go to. Note that industrial factions will often have raiders using go-juice, who will run ahead of the group and trigger the trap early.

If the Classic Mortars storyteller setting is turned on, the mortar miss radius is increased to 12 tiles, reducing the launched shell's effectiveness. This makes the IED a more effective option.

Version history[edit]

  • 1.1.0 - IEDs explode when bullets hit them. This allows the player to purposefully shoot them to set them off.
  • ? - texture updated. Before 1.3.3159 and presumably sometime after 1.0.2096 to correspond with antigrain warhead texture change.