Destroyed By His Own Law

What actually happened

As chancellor of Qin, Shang Yang's Legalist reforms made the state a machine: impersonal law, collective punishment, rank by battlefield merit rather than birth. The machine worked. Qin became the power that would eventually unify China, and it crushed the aristocracy that had run things by privilege.

When his patron Duke Xiao died in 338 BC, the crushed aristocracy came for him. The Records of the Grand Historian tells the inn scene, the fugitive undone by his own identification law, before his defeat, execution by chariots, and the extermination of his family under his own three-generations clause.

Sima Qian wrote a century and a half later and clearly relished the irony; the episode attributes the poetic justice to the historian while keeping the reforms and the fall as history.

The play to remember

Impersonal law is a weapon that doesn't remember who built it. If you design the machine to spare no one, start by assuming it won't spare you.