In making tactical dispositions, the highest pitch you can attain is to conceal them.

When the enemy's envoy's speak in humble terms, but continues his preparations, he will advance. When their language is deceptive but the enemy pretentiously advances, he will retreat. When the envoys speak in apologetic terms, he wishes a respite. When without a previous understanding the enemy asks for a truce, he is plotting. When the enemy sees an advantage but does not advance to seize it, he is fatigued.

Therefore the skillful leader subdues the enemy's troops without any fighting; he captures their cities without laying siege to them; he overthrows their kingdom without lengthy operations in the field.

Move not unless you see an advantage; use not your troops unless there is something to be gained; fight not unless the position is critical.

He who wishes to fight must first count the cost

If we know that the enemy is open to attack, but are unaware that our own men are not in a condition to attack, we have gone only halfway towards victory.

In your deliberations, when seeking to determine the military conditions, let them be made the basis of a comparison, in this wise: which of the two generals has the most ability? on which side is Discipline most rigorously enforced? which army is stronger? on which side are the officers and men more highly trained? in which army is there the greater constancy both in reward and punishment?