If their forces are substantial, prepare for them; if their forces are strong, avoid them.

Probe him and learn where his strength is abundant and where deficient.

It is essential to seek out enemy agents who have come to conduct espionage against you and to bribe them to serve you. Give them instructions and care for them. Thus doubled agents are recruited and used.

So in war, the way is to avoid what is strong, and strike at what is weak.

It is the rule in war, if ten times the enemy's strength, surround them; if five times, attack them; if double, be able to divide them; if equal, engage them; if fewer, defend against them; if weaker, be able to avoid them.

It is the business of a general to be serene and inscrutable, impartial and self-controlled.

The proximity of an army causes prices to go up; and high prices cause people's substance to be drained away. When their substance is drained away, they will be afflicted by heavy exactions. With this loss of substance and exhaustion of strength, the homes of the people will be stripped bare, and their incomes dissipated.