Indirect fire weapons cannot be fired at targets within their minimum range (see weapon profiles), measured from the centre of the weapon itself. If a target is found to be within this minimum range the shot misses automatically and is ignored. The crew of an indirect firing weapon must still be able to see their target unit to shoot, unless a spotter is employed. However, the crew can direct their fire against a target even if friends are in the way, as shots pass far over the heads of intervening friendly troops because of the high trajectory.
When firing HE shells using indirect fire, a 6 is required to hit, regardless of any modifier. In the following turn, if the shooter fires at the same target unit, and if the shooter has not moved from their position (i.e. it receives a Fire order), and if the target unit has not moved from their position (to count as 'moved', the entire unit must be at least 2" away from the area that it was covering before), a hit is scored on a 5+. This represents the shooter adjusting his aim by observing where shots are falling. If the shooter continues to fire under the same conditions explained above, a hit is scored on a 4+ in the next turn, then 3+ and finally 2+ in all subsequent turns. However, if a hit is scored in any turn, the shooter is zeroed in on the target and as long as it does not move, all further shots hit on 2+, even if the target unit is then lost from view (obscured by a moving vehicle, a spotter is killed, etc.).
When fired against vehicles, hits from indirect fire weapons always strike the vulnerable top armour, counting the +1 penetration modifier to damage regardless of the actual position of the firer. If an open-topped armoured vehicle is hit by indirect fire add the +1 penetration modifier to the roll to damage, and also add +1 to the die roll on the damage results table.
Weapons cannot be fired indirectly by a unit that was in Ambush that turn - indirect fire takes time. Howitzers and mortars can also fire smoke shells to lay a smoke screen.
If a unit includes both normal weapons and indirect firing weapons (such as one or more light mortars inside a unit of riflemen), any mortar in the squad can pick a target individually, regardless of what the rifles and other mortars in the squad are doing.
Ranging in is kept track of separately for each mortar.