From the time the general receives his commands from the ruler, unites the armies, and assembles the masses, to confronting the enemy and encamping, there is nothing more difficult than military. In military combat what is most difficult is turning the circuitous into the straight, turning adversity into advantage.
Thus if you make the enemy's path circuitous and entice them with profit, although you set out after them you will arrive before them. This results from knowing the tactics of the circuitous and the direct.
Thus combat between armies is advantageous, combat between masses is dangerous. If the entire army contends for advantage, you will not arrive in time. If you reduce the army's size to contend for advantage, your baggage and heavy equipment will suffer losses. For this reason if you abandon your armour to race forward day and night without encamping to contend for gain, the Three Armies' generals will be captured. The strong will be first to arrive, while the exhausted will follow. With such tactics only one in ten will reach the battle site. If the army does not have baggage and heavy equipment, it will be lost; if it does not have provisions, it will be lost; if it does not have stores, it will be lost.
Thus one who does not know the plans of the feudal lords cannot prepare alliances beforehand. Someone unfamiliar with the mountains and forests, gorges and defiles, the shape of marshes and wetlands cannot advance the army. One who does not employ local guides cannot guide advantages of terrain.
Thus the army is established by deceit, moves for advantage, and changes through segmenting and reuniting. Thus its speed is like the wind, its slowness like the forest; its invasion and plundering like a fire; unmoving, it is like the mountains. It is as difficult to know as the darkness; in movement it is like thunder.
Take control of the strategic balance of power and move. The one who first understands the tactics of the circuitous and the direct will be victorious.
When the men have been unified, the courageous will not be able to advance alone, the fearful will not be able to retreat alone. This is the method for employing large numbers
The ch'i (spirit) of the Three Armies can be snatched away; the commanding general's mind can be seized. For this reason, in the morning their ch'i is ardent; during the day their ch'i becomes indolent; at dusk, their ch'i is exhausted. Thus one who excels at employing the army avoids their ardent ch'i and strikes when it is indolent or exhausted. This is the way to manipulate ch'i.
In order, await the disordered; in tranquility, await the clamorous. This is the way to control the mind. With the near await the distant; with the rested await the fatigued; with the sated await the hungry. This is the way to control strength.
Do not intercept well-ordered flags, do not attack well-regulated formations. This is the way to control changes.
Do not approach high mountains, do not confront those who have hills behind them. Do not pursue feigned retreats. Do not attack animated troops. Do not swallow an army acting as bait. Do not obstruct an army retreating homeward. If you besiege an army you must leave an outlet. Do not press an exhausted invader. These are the strategies for employing the military.