Taking the bait
During the Warring States period in China (Circa 475 BC to 221 BC) the kingdoms of Qi and Wei came into conflict with one another. The King of Qi took on the counsel of Sun Pin, who was supposedly a relation of the great Chinese strategist and author Sun Tzu.
Sun Pin had determined that the King of Wei believed that the soldiers of Qi were inferior in every way to his own troops and so he bade the King of Qi to invade the lands of Wei. Sun Pin counseled that on the first night the army should light 1000 campfires, the next night, 500 and then on the third night, half as many again. The King of Wei, through his network of spies would imagine that the soldiers of Qi were deserting.
The King of Wei, believing that the army of his enemy was indeed disintegrating sent his cavalry led by his most trusted commander to rout the remaining enemy troops. Hearing that the army of Wei would soon be upon them the King of Qi retreated his army into a narrow gorge. He had his soldiers cut down a huge tree and placed it in the road. Furthermore he made his soldiers strip the bark off the tree and engraved the following message onto the trunk
The general of the army of Wei will die at this point.
The King of Qi then had his archers hide on either side of the ravine. When the cavalry arrived night had already fallen. They entered the ravine but were soon blocked by the ‘fallen’ tree. A message was sent to the commander that something was written on the tree. Coming up the column the commander ordered a torch be lit so that he could read the message.
This was the signal for the archers to fire. Realizing he had be lured into a trap the general of the army of Wei killed himself.