Repeated analysis of the patterns of IEDs led the battalion to innovative ways to avoid them and also prevent them from being employed. The battalion identified the following as its main threats, in order of importance: Improvised explosive devices (IEDs), direct fire (particularly from snipers), indirect fire (typically mortars), vehicle-borne IEDs, a medium-sized attack(such as two dozen insurgents attacking a fixed position), a large-sized counterattack (such as a hundred insurgents joining an attack on a patrol), and a complex attack that might involve several of the previously-described methods. Simplifying the types of threats to a manageable number, then forcing each Marine to "war game" his response to each threat situation, was tremendously valuable because it allowed Marines to respond instinctively.