If those who are sent to draw water begin by drinking themselves, the army is suffering from thirst. [One may know the condition of a whole army from the behavior of a single man.]

He will win who, prepared himself, waits to take the enemy unprepared.

Bravery without forethought, causes a man to fight blindly and desperately like a mad bull.  Such an opponent, must not be encountered with brute force, but may be lured into an ambush and slain.

Great results, can be achieved with small forces.

If your opponent is of choleric temper,  seek to irritate him.  Pretend to be weak, that he may grow arrogant.

There are roads which must not be followed, armies which must not be attacked, towns which must not be besieged, positions which must not be contested, commands of the sovereign which must not be obeyed.