Only Artillery, along with some anti-tank, antiaircraft, and heavyweapon units may engage in artillery combat. There are three possible fire missions in CAOS – barrage, counter battery and fire support. All artillery may fire and move within the same turn, but motorized artillery may move slightly further and self-propelled artillery may its entire movement allowance further while executing a fire mission. This allows for such complex artillery maneuvers as the self propelled howitzer "drive by shooting" just as long as the artillery is in range on the proper impulse to pull it off.
Barrage: All artillery, anti-tank, antiaircraft and heavy weapon units with a barrage value and a Fire Mission Barrage order directed against the same hex and unit class during the same movement and combat impulse combine their barrage strength in order to resolve barrage combat. For example, artillery from five different hexes all firing on mechanized targets in the same target hex on impulse 5 would combine their barrage value. While another group of artillery targeting the same hex on impulse 5 but targeted against infantry would execute a separate bombardment.
Specific Target Edit
As mentioned above, when a barrage is planned you select a specific target.
This is simply the target emphasis, other enemy units in the hex may be damaged from the barrage, but the target type you pick will be hit hardest.
Collateral Damage Edit
Artillery is not 100% accurate, nor would you want it to be. Any hostile unit in the target hex may take collateral damage from a bombardment, so an infantry unit could take losses from a bombardment directed against mechanized units, simply the mechanized units are more LIKELY to take losses from the bombardment targeting them specifically.
One of the most powerful but massively underappreciated values of barrage is its ability to "pin" a target. Targets that are pinned exert no zone of control on next impulse. So a unit that is barraged and pinned on impulse 1 will exert no zone of control on impulse 2. This is useful for pinning enemy units and then moving in to encircle them while they have no zone of control or for bypassing defensive positions by pinning them and then literally moving by.
Counter Battery Edit
Counter battery: Artillery, anti-tank, antiaircraft and heavyweapon units with a barrage value and a Fire Mission Counter Battery order will execute a barrage attack against a targeted enemy artillery unit - or stack of artillery as long as the target is within range. In all other ways the order is identical to Barrage, it is simply used to specifically target artillery.
Fire Support Edit
Fire Support: Artillery, anti-tank, antiaircraft and heavyweapon units with a fire support value may target a friendly unit with a Fire Mission Support order. If that unit is involved in ANY combat at ANY point during turn resolution then the artillery add their fire support value to any combat involving that unit. Thus if the targeted friendly unit is involved in 6 different combats during the turn then the fire support will be applied to all 6 combats. However, the artillery executing the fire support mission will take cohesion loss for each time it fires in support of the targeted unit.
In order to receive the benefit of fire support the selected friendly unit must be within the supporting artillery unit’s range during the impulse when the combat occurs. If for any reason the unit leaves the range of the artillery or the artillery moves out of range of the targeted unit, the order will not be carried out.
Fire support is often the safest way to fulfill the artillery portion of Combined Arms. For both technical and doctrinal reasons some artillery, anti-tank and antiaircraft units are incapable of carrying out a Fire Mission Support order.