If you know both yourself and your enemy, you can win a hundred battles without a single loss.

The expert in battle seeks his victory from strategic advantage and does not demand it from his men.

This does not mean that the enemy is to be allowed to escape. The object is to make him believe that there is a road to safety, and thus prevent his fighting with the courage of despair. After that, you may crush him.

It is only the enlightened ruler and the wise general who will use the highest intelligence of the army for the purposes of spying, and thereby they achieve great results.

Do not swallow bait offered by the enemy. Do not interfere with an army that is returning home.

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.

Those skilled in attack move as from above the nine-fold heavens. Thus they are capable both of protecting themselves and of gaining complete victory.