Birds rising in flight is a sign that the enemy is lying in ambush; when the wild animals are startled and flee he is trying to take you unaware.
The greatest victory is that which requires no battle.
Thus the expert in battle moves the enemy, and is not moved by him.
If those who are sent to draw water begin by drinking themselves, the army is suffering from thirst.
The natural formation of the country is the soldier's best ally
He who knows his enemy and himself well will not be defeated easily.