空城计

Explanation: Refers to critical situations, disguise emptiness, deceive each other's strategies. 　　Source: Ming Luo, "Three Kingdoms" in the story of the fall of Shu the middle of the street kiosks Ma Su, Wei Sima Yi shuaibing encroaching upon the West, Zhuge Liang to meet the enemy without an army, but the calm calm, open the gates, arrogant in the tower on the piano. Sima Yi has suspected ambush, led his troops retreated.