孙子曰:凡用兵之法,将受命于君,合军聚众。泛地无舍,衢地合交,绝地无留,围地则谋,死地则战,途有所不由,军有所不击,城有所不攻,地有所不争,君命有所不受。
Sun Tzu says: In the art of war, after the general has received orders from the sovereign and assembled his army, he must avoid camping on scattered ground, form alliances on communicating ground, not linger on desperate ground, employ stratagems on hemmed-in ground, and fight on deadly ground. There are roads that should not be taken, armies that should not be attacked, cities that should not be besieged, and grounds that should not be contested. There may even be orders from the sovereign that should not be carried out.
故将通于九变之利者,知用兵矣;将不通九变之利,虽知地形,不能得地之利矣;治兵不知九变之术,虽知五利,不能得人之用矣。
A general who is versed in the nine variations of terrain knows how to use his troops. A general who does not understand these nine variations will not be able to use his troops to advantage, even if he knows the configuration of the ground. A general who does not understand the nine variations will not be able to use his men effectively, even if he knows the five advantages.
是故智者之虑,必杂于利害,杂于利而务可信也,杂于害而患可解也。
Thus, the deliberations of a wise man must consider both advantages and disadvantages. By considering advantages, he can accomplish his mission with confidence; by considering disadvantages, he can avoid dangers.
是故屈诸侯者以害,役诸侯者以业,趋诸侯者以利。
To subdue princes, one must threaten them with harm; to employ them, one must give them tasks; to attract them, one must offer them advantages.
故用兵之法,无恃其不来,恃吾有以待之;无恃其不攻,恃吾有所不可攻也。
Thus, in war, one should not rely on the enemy not attacking, but on being ready to receive him; one should not rely on the enemy not attacking, but on having positions that he cannot attack.
故将有五危,必死可杀,必生可虏,忿速可侮,廉洁可辱,爱民可烦。凡此五者,将之过也,用兵之灾也。覆军杀将,必以五危,不可不察也。
A general may commit five fatal mistakes: if he is willing to die, he may be killed; if he clings too much to life, he may be captured; if he is quick-tempered and impulsive, he may be provoked; if he is overly concerned with reputation, he may be humiliated; if he is too fond of his men, he may be harassed. These five faults are mistakes for a general and disasters for an army. The defeat and death of a general always stem from these five faults; they must be carefully examined.