Each war machine can fight as a single unit of one model rather like a chariot or a hero riding a large monster. This is the usual way in which war machines are deployed, especially in small armies which might have only one or two machines.

If an army includes several war machines of the same type these can be organised into units called batteries. War machines are automatically assumed to be formed into a battery when deployed within 5" of each other at the start of the game. For purposes of forming batteries all stone throwers count as the same type of machine regardless of their size, and the same is true of cannons and great cannons.

When fighting in a battery each war machine must remain within 5" of another machine in the same battery forming a rough line or clump. The battery does not have to adopt a formation as such and for this reason is referred to as a 'loose' unit. The models are still moved individually but must remain within their battery for the duration of the game.