War tactics and strategy. The art of getting a large number of people to successfully kill other people that are trying to do the same to you. This will range from the simple, "So people surrounding us is bad?" to the extraordinarily complicated, "We'll move the archers on the fourth ridge. Naturally they'll attempt to flank coming from the west with one of their reserve companies, and at that point we'll use that tree line hiding our cavalry to ride down on them as they are winded, and if they break, then..."