Crossing the Sea under Camouflage is the first stratagem in the Thirty-Six Stratagems, belonging to the “Stratagems for Winning.” Its core idea is to deceive the enemy through disguise and feigned normalcy, causing them to lower their guard, thereby enabling covert action to achieve the objective.

Allusion and Origin
The name of this stratagem comes from a historical legend about Xue Rengui’s campaign against the Eastern Liao in the Tang Dynasty. According to the story, Emperor Taizong of Tang (Li Shimin) personally led an expedition against Goguryeo but hesitated because he feared the vast sea. General Xue Rengui devised a plan: he hid the army inside cabins decorated with colored curtains, claiming they were the residences of wealthy commoners, and invited the emperor in to drink and enjoy himself. Only when the emperor noticed was he already at sea, having crossed it. The tale first appeared in the Yuan Dynasty story A Brief Account of Xue Rengui’s Campaign against the Eastern Liao and was later included as the first stratagem in the Thirty-Six Stratagems during the Qing Dynasty.

Core Meaning
This stratagem emphasizes that “concealment” is the means, while “crossing the sea” is the goal. It exploits people’s habitual disregard for things they see every day, hiding one’s real intentions behind open actions to achieve a surprise effect. Historical examples include the Sui general He Ruobi’s conquest of the Chen dynasty, as well as deception operations in modern warfare—all typical applications of this stratagem.