When you surround an army, leave an outlet free. Do not press a desperate foe too hard.

Pretend inferiority and encourage his arrogance.

The end and aim of spying in all its five varieties is knowledge of the enemy; and this knowledge can only be derived, in the first instance, from the converted spy. Hence it is essential that the converted spy be treated with the utmost liberality.

The clever combatant imposes his will on the enemy, but does not allow the enemy's will to be imposed on him.

Whoever is the first in the field and awaits the coming of the enemy will be fresh for the fight... Therefore the clever combatant imposes his will on the enemy... By holding out advantages to him, he can cause the enemy to approach of his own accord; or by inflicting damage, he can make it impossible for the enemy to draw near.

What enables the wise sovereign and the good general to strike and conquer, and achieve things beyond the reach of ordinary men, is foreknowledge.

With regard to narrow passes, if you can occupy them first, let them be strongly garrisoned and await the advent of the enemy.