Attack where he is unprepared; sally forth when he does not expect you.

Invincibility lies in the defense; the possibility of victory in the attack.

If the enemy opens the door, you must race in.

Pretend inferiority and encourage his arrogance.

He will win who knows when to fight and when not to fight.

Subjugating the enemy's army without fighting is the true pinnacle of excellence.

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