Petty warfare is composed of those lesser actions in war, "such as reconnaissance, ambushes, patrolling, and fighting in broken ground." "Medieval strategists made use of many forms of warfare, including set-piece battles, of course, as well as the petty warfare of raiding and harassment." "Guerrillas, as Lieber defined them, were not tied directly to an army, and "carried on a petty war by raids, extortion, destruction, and massacre."