Sunzi opens his treatise by establishing that warfare is a matter of vital state importance, governed by five constant factors: the moral law, heaven, earth, the commander, and method. He emphasizes that all warfare relies on deception, urging generals to appear inactive when active and near when far, while calculating extensively before any engagement. Because prolonged campaigns drain state resources and exhaust soldiers, the author argues that speed and decisive victory are paramount, famously declaring that the supreme art of war is to subdue the enemy without fighting.
The text details tactical dispositions, stressing that skilled leaders first place themselves beyond defeat and only then wait for enemy vulnerability. Sunzi explains how to manipulate large forces using direct and indirect methods, comparing the momentum of an army to water flowing down a mountain or a round stone rolling down a slope. He advises generals to impose their will on opponents, exploiting weak points while keeping their own positions and dispositions hidden from view.
Terrain management forms a major component of the strategy, as Sunzi categorizes ground into distinct types—such as accessible, entangling, and desperate—and outlines specific responses for each. He warns against the five dangerous faults in leadership, including recklessness, cowardice, and a hasty temper, noting that soldiers must be treated with humanity yet controlled by iron discipline.
The final sections address specialized tactics, including attacks by fire and the critical deployment of intelligence. Sunzi outlines five types of spies, arguing that foreknowledge cannot be gained from spirits or calculation, but only from human agents. He concludes that maintaining an effective espionage network is essential for any ruler or general seeking lasting success.
