"Mortar launcher. Lobs bombs over walls. Very inaccurate but long-ranged."
- For additional guidance, see Defense structures#Mortars .
The Mortar is a manned stationary siege defense mechanism. It launches 1-round artillery mortar shells at any enemy that enters its 500-tile firing radius, or at a target set by the player. Once an enemy has entered within 30 tiles of the mortar, it will cease fire. The range indicator of mortars is not its actual range, but the size of its blind spot. It cannot fire if covered by a roof. It has a 4-second warmup time, a 28-second cooldown, and a 13-tile forced miss radius. Mortars explode in a 4.9-tile radius when destroyed, dealing 50 damage.
Loading different shells into it will produce different effects. These shells can be manually extracted from the mortar. Mortars can be set to accept different types of shell.
Mortars require a pawn each to load and fire shells. Their skills have no effect on accuracy, however pawns incapable of violence will refuse to man them. Unlike drafted colonists, mortar personnel do not relieve their position once the battle is over and must be manually unassigned. There is no way to increase mortar accuracy.
Enemy sieges typically spawn with 2 mortars, that will be constructed by the enemy, and then fired at your base. Shells fired from mortar's will break through constructed roofing but not through mountains (or any tile underneath one). Following a siege, it is possible to loot mortars from siege attacks, so long as the enemy builders complete construction, by reinstalling them in your base. Pawns assigned to construction will haul them to their new location.
In Beta 18 the three types of mortars (Incendiary, EMP and explosive) were replaced with a single type, which fires different types of shells that achieve the same effect. In addition, two new shells are added, the firefoam shell and the antigrain warhead.
In 1.1.2618 the cost was increased from 100 steel, 50 materials and 4 components.