A Battle of Wits (rōmaji: Bokkō or Bokukō; literally: "Mohist Attack") is a 2006 Hong Kong historical-action-war-drama film, based upon a Japanese historical fiction novel of the same title. A manga series was written by Hideki Mori, also based on the novel. Directed by Jacob Cheung, the film starred Andy Lau, Ahn Sung-ki, Wang Zhiwen, Fan Bingbing, Nicky Wu and Choi Siwon.
The film is set in the Warring States Period of Chinese. The Zhao state invades the city-state of Liang. Ge Li, a Mohist, comes to Liang to help defend the city, without permission from the Mohist leaders. He warns the people of Liang of the dangers of surrendering to the invading Zhao army. The king of Liang is worried about Ge Li inciting war amongst his people, but eventually decides to allow Ge to temporarily aid in defending Liang.
Ge Li creates a bulwark and various traps to halt the Zhao army's advance. The prince and generals of Liang were initially doubtful of Ge's ability as a military tactician, but time after time, Ge's tactics prove useful in holding off the invaders. The prince begins to respect Ge Li for his wisdom and experience. After Ge successfully defends Liang from the enemy, superior in numbers, he becomes a highly-revered hero by the local populace.
The king of Liang feels threatened when he sees Ge Li's growing popularity, so he plots to have Ge stripped off his military power and executed on false charges. Ge has just returned from a scouting mission when he is accused of starting a war under false pretenses at the gates of Liang. The prince pretends to fight with Ge Li and secretly asks Ge to take him hostage in order to buy time for Ge to escape. Ironically, the improved arrows that Ge used to defend Liang were used against him. Ge manages to leave unharmed, but the prince is tragically killed by the arrows. Meanwhile, Ge Li's supporters are falsely accused of plotting a rebellion against the king of Liang, and they are tortured and executed.
The king of Liang foolishly believes that the Zhao army has left but he is caught off guard by the Zhao forces in a surprise attack. Ge Li returns with a surviving group of Liang soldiers to save the city. After the conflict, Ge leaves with some orphans from Liang to promote peace among the various warring states. The king of Liang is killed five years later and eventually the Qin state will conquer all the other states and unite China under the Qin Dynasty.