Sun Tzu says

ALL WARFARE is based on deception.

Offer the enemy a bait to lure him; feign disorder and strike him.

In war, numbers alone confer no advantage. Do not advance relying on sheer military power.

The enemy must not know where I intend to give battle. For if he does not know where I intend to give battle he must prepare in a great many places. And when he prepares in a great many places, those I have to fight in any one place will be few.

For to wiin 100 victories in 100 battlers is not the acme of skill. To subdue the enemy without fighting is the acme of skill.

Thus, what is of supreme importance in war is to attack the enemy's strategy....

Source: Forbes 9 Dec 1991 p.162