Shang Yang, a brilliant legalist thinker of pre-Qin China, was sharp and studious from a young age, with a particular passion for criminal law. He once served as a minor official in the state of Wei, but King Hui of Wei never recognized his talents.
In 361 BCE, Duke Xiao of Qin, determined to reform the state, issued a decree seeking talented advisors. Hearing this, Shang Yang left the state of Wei and journeyed to Qin. After three audiences with the duke, who recognized his exceptional ability, Shang Yang was appointed as the Left Chief Minister and tasked with drafting new laws to transform the kingdom.
Shang Yang reformed the old systems of the Qin state, drafting a new set of laws: five households formed a unit, ten units were linked; if one family committed a crime and the other nine failed to report it, all ten were punished together; those who surrendered to the enemy were beheaded, and those who harbored criminals were sentenced; those with merit were rewarded with titles and lands. Within a decade of implementing these laws, Qin grew powerful. Shang Yang then divided the state into thirty-one counties, appointed magistrates and clerks, surveyed land, and standardized measures, gradually making Qin the strongest among the warring states.
Shang Yang's new laws were exceptionally strict and harshly enforced. During his decade as prime minister of the Qin state, he offended many high-ranking officials and nobles, even punishing the crown prince's tutors as a warning to the prince himself. Countless powerful ministers harbored deep resentment toward him, but because Duke Xiao of Qin trusted him completely, they dared not speak out—only fuming in silence.
A man named Zhao Liang visited Shang Yang and warned him, "You gained the King of Qin's favor through a eunuch—hardly the proper path to fame. As prime minister, you build grand palaces instead of benefiting the people, earning no true merit. You punished the crown prince's tutor and crushed the people with harsh laws, sowing seeds of resentment. Teaching through ritual and virtue runs far deeper than ruling by fear. Your reforms defy common sense, your laws violate tradition, and now you're enfeoffed as Lord Shang while punishing Qin nobles, executing Zhu Huan, and branding Gongsun Jia—all making enemies. Why not return your lands and retire to the mountains? If you cling to wealth and power, flaunting your influence in Qin while ignoring the people's anger, the moment the king no longer needs you, your life will be in danger."
Shang Yang refused to heed Zhao Liang's advice.
After Duke Xiao of Qin died, King Hui of Qin ascended the throne. Someone falsely accused Shang Yang of plotting rebellion, so the king sent men to arrest him. Shang Yang fled in haste, reaching the Hangu Pass at nightfall. Seeking lodging at an inn, the innkeeper, unaware of his identity, told him, "Lord Shang's law decrees that anyone sheltering a guest without proper credentials will be punished." Shang Yang sighed deeply and lamented, "Alas, the very laws I created have now ensnared me!" He then escaped to Wei, but the people there, resenting his past defeat of their army, refused him shelter and sought to hand him over to Qin. Finally, fleeing to his fiefdom of Shang, he rallied his followers to attack Zheng, but was defeated by Qin forces and executed by dismemberment.
Later, the idiom "Hoist by One's Own Petard" came to mean making laws that end up harming oneself.
Source: *Records of the Grand Historian*, "Biography of Lord Shang"
Meaning of the Idiom: Later, the Chinese idiom "作法自弊" came to describe making laws that end up harming oneself.