The mortar is the Imperial Guard’s go-to indirect-fire weapon: a simple, muzzle-loaded tube that lobs explosive shells over friendly troops and onto the enemy behind cover. It’s cheap to build, easy to maintain, and it’s been doing the same job for the Astra Militarum for thousands of years.
What the mortar is
A mortar is a muzzle-loaded projectile weapon that fires an explosive shell on a high-arching trajectory. It’s not accurate in the way a lascannon is. Instead, it drops shells down onto rear ranks and infantry formations, pinning them in place while the Guard manoeuvres.
Its whole appeal is simplicity. Compared to fancier artillery, a mortar is easy to build, easy to fix, and easy to keep firing. That’s why the Imperial Guard loves it, and why it’s still in service on worlds that have barely heard of a plasma generator.
How it’s used
Mortars shine when they’re firing from behind cover. They lay down a curtain of fire that enemy infantry can’t easily answer, though the tradeoff is that they need good targeting data to be useful.
That means spotters. A spotter finds the target, by eye or through a remote servitor, and sends a fire request up the chain to the platoon command squad. The command squad works out a firing solution and passes it to the mortar teams, who adjust as the fight moves. Get the vox protocol wrong and you’ll drop shells on your own line.
- Indirect fire, so it hits what the firer can’t see directly.
- Best against massed infantry, not armour.
- Needs spotters and clear vox traffic to avoid friendly fire.
Patterns and variants
The most famous pattern is the Mk.IX Accatran, favoured by the Elysian Drop Troops. It’s an automatic mortar fed by a five-round revolving drum, light enough for two Guardsmen to carry by its handles. Once set up, it can be fired by a short-range remote control with a range of about 100 metres, letting the firer act as their own spotter and dump all five rounds on one spot.
Beyond that, the mortar family gets big fast. The Heavy Mortar is a support version usually mounted on a Griffon Mortar Carrier or towed by a Trojan or Centaur. The Heavy Quad-Launcher packs four barrels for rapid light artillery. The Colossus Siege Mortar throws enormous rocket-propelled shells from the Colossus Bombard, and the Dominus Triple Bombard mounts three sequentially firing bombards on one tank.
| Variant | What it is |
|---|---|
| Heavy Mortar | Larger support mortar, mounted or towed |
| Heavy Quad-Launcher | Four-barrel rapid light artillery |
| Colossus Siege Mortar | Fires huge rocket-propelled shells from a Bombard |
| Dominus Triple Bombard | Three bombards on the Dominus siege tank |
| Gorgon Mortar | Clears the way for troops leaving Gorgon transports |
| Kalliope Rocket Mortar | Used by the Imperialis Militia |
| Mole Mortar | Sub-surface launcher, invented by the Squats |
| Rapier Armoured Carrier | Can be fitted with quad-mortars |
Where it fits in the lore
The mortar is a good example of what the Imperial Guard is: not the most advanced force in the galaxy, but one that wins through volume, grit, and weapons that keep working when everything else breaks. It also shows up in odd corners of the setting, like the Squat-designed Mole Mortar, which fires from beneath the ground.
There’s a note of disagreement in the sources about some variant details, so treat the finer points of individual patterns as fuzzy. The core idea doesn’t change: a tube, a shell, and a crew who know how to drop it on the right heads.
Key facts
- The mortar is a simple, muzzle-loaded indirect-fire weapon used by the Imperial Guard.
- It fires explosive shells on a high arc to hit enemies behind cover.
- It’s prized for being cheap to build and maintain compared to advanced artillery.
- The Mk.IX Accatran pattern has a five-round drum and a remote control with a roughly 100-metre range.
- Variants range from the Heavy Mortar to the Colossus Siege Mortar and the Squat-designed Mole Mortar.
FAQ
What is the mortar used for in Warhammer 40k?
It’s an anti-personnel weapon. The Imperial Guard uses mortars to break up infantry formations and pin enemies down with indirect fire from behind cover.
Which faction uses the mortar?
Mainly the Astra Militarum, also called the Imperial Guard. The Squats invented the Mole Mortar, and the Imperialis Militia fields the Kalliope Rocket Mortar.
What’s the most famous mortar pattern?
The Mk.IX Accatran pattern, an automatic mortar with a five-round drum magazine, favoured by the Elysian Drop Troops.