Trouble The Water To Catch The Fish
Before engaging your enemy's forces create confusion to weaken his perception and judgment. Do something unusual, strange, and unexpected as this will arouse the enemy's suspicion and disrupt his thinking. A distracted enemy is thus more vulnerable.
Spring and Autumn Period China
In 632 BC the armies of Jin and Chu faced each other at Chengbu before the battle of the same name. Chu sent an envoy to Jin requesting to fight a chariot duel the next day to which the Jin ruler, Duke Wen, agreed. In the morning Duke Wen climbed to the top of an observation tower and looking down on his camp's preparations said: A Young and old conduct themselves according to ritual. They are fit for use!" He then ordered his troops to cut down trees to be used as part of an unorthodox tactic. While the chariot duel was underway Duke Wen launched a sudden cavalry attack against the Chu right wing causing it to collapse in. At the same time as the right was being pushed into the main body, the Jin troops in the center raised the retreat pennants and began pulling back. As the Jin troops retreated they dragged behind them the trees they had cut down earlier that morning. This raised such a dust cloud that the Chu commanders thought the Jin were fleeing in panic and eagerly gave chase. When the main body of the Chu army was enveloped in the cloud of dust they were unable to see that the Jin forces had split into two divisions and had turned around. The Jin attacked in a classical pincer movement on both of the Chu flanks. The result was a resounding defeat after which the Chu general was ordered to commit suicide. Duke Wen had taken advantage of the distraction provided by the chariot duel to launch both a surprise attack, and a retreat, manipulating the Chu forces into a trap.