Zhuge Liang's Eight Trigrams Array trapped and defeated Sima Yi

Kong Ming’s defeat of Sima Yi through the Eight Trigrams formation turns a contest of military strategy into a decisive rout. After challenging Sima Yi to match formations, Kong Ming uses a pattern drawn from the Yi Jing to lure the Wei army into a supernatural maze; he captures three commanders, and then anticipates and repels Sima Yi’s renewed attack.

Strategic Contest

The confrontation follows a direct challenge between Kong Ming and Sima Yi to demonstrate their command of military strategy. Their formations draw on mystical ideas and texts, placing the contest between the two commanders on both tactical and symbolic ground. Kong Ming’s formation is based on the Eight Trigrams of the Yi Jing, while the account describes its effect as a supernatural maze that overwhelms Sima Yi’s forces.

The Formation and Its Captives

The maze ends in a defeat for Sima Yi and gives Kong Ming control of three leading Wei commanders: Zhang Hu, Dai Ling, and Yue Chen. Rather than keep them as prisoners or execute them, Kong Ming dismisses them and sends them back to Sima Yi with a rebuke to study military affairs more thoroughly. He returns their weapons and those of the captured officers, but sends the soldiers back stripped and with blackened faces. The treatment combines release with humiliation, making the defeated force carry a message of Kong Ming’s confidence back to its commander.

Sima Yi’s Counterattack

The humiliation provokes Sima Yi to commit his entire force to a renewed attack. Kong Ming has anticipated this response. An assault on the Wei rear, led by Guan Xing, scatters the army; the account says that six or seven out of every ten Wei soldiers die that day. With no further option, Sima Yi retreats to the south side of the Wei River and does not appear again in the episode.

Significance

The episode makes the contrast between the commanders a matter of foresight as much as force. Sima Yi escalates after being humiliated, while Kong Ming’s prediction of that reaction allows him to turn the counterattack into a second defeat. The formation’s supernatural presentation magnifies Kong Ming’s strategic authority, while the return of the captured officers and the humiliation of the soldiers extend his victory beyond the battlefield into a deliberate demonstration of command.