[Idiom]: Zuò Fǎ Zì Bì (literally: "to make laws that end up ensnaring oneself")
[Explanation]: To be harmed by one's own laws or rules. Generally refers to reaping what one has sown or suffering the consequences of one's own actions.
[Story]: When Shang Yang implemented his reforms in the state of Qin, he first abolished the privileges of the nobility, establishing a new system where noble ranks were granted strictly according to military merit. This deprived the nobles of their traditional right to receive rewards without effort, causing them great resentment towards Shang Yang. However, Shang Yang had the strong support of Duke Xiao of Qin, so despite their hatred, the nobles could do nothing.
After the reforms, Qin quickly grew powerful. Productivity increased dramatically, the state treasury became full, and its soldiers fought with great courage, making Qin a formidable power that intimidated the other six states. Because of his success with the reforms, Shang Yang was granted fifteen cities in the region of Shang as a fief, earning him the title "Lord Shang." From then on, people referred to Gongsun Yang as Shang Yang.
During the reform process, the teacher of the Crown Prince (heir to the throne) violated the new laws. The nobles and court officials watched with schadenfreude, eager to see how Shang Yang would handle this difficult situation. To ensure the new laws could be enforced, Shang Yang requested permission from Duke Xiao and dealt with the offense strictly and impartially according to the law. Although the Crown Prince pleaded for leniency for his teacher, it was to no avail. From that moment, the Crown Prince harbored a deep hatred for Shang Yang and was determined to eliminate him as soon as possible.
After Duke Xiao died following a 22-year reign, the Crown Prince ascended the throne, known in history as King Huiwen. Knowing that King Huiwen deeply resented Shang Yang, the nobles began spreading rumors and slander. Some even falsely accused Shang Yang of plotting rebellion. King Huiwen well understood that Shang Yang had neither the motive nor the means to rebel. However, seeking revenge, he ordered Shang Yang's arrest.
After Duke Xiao's death, Shang Yang realized he had lost his patron and did not dare remain in the capital for long, so he returned to his fief. When he heard rumors that he was being accused of treason, he knew that execution was inevitable sooner or later. He fled alone from his home, intending to escape to another state to avoid disaster.
As dusk fell and crows flew homeward against the setting sun, Shang Yang hurried along, desperate to leave Qin territory. Arriving at a border pass, he was stopped by the guards, who declared, "Lord Shang's decree: No one may leave the city after dark except on official business." Only then did Shang Yang realize he needed to find lodging for the night. He went to an inn and asked for a room. The innkeeper came out and said, "Of course we welcome guests, but may I ask who you are? If I don't verify your identity, I will be executed. These are Lord Shang's laws; they cannot be broken." Shang Yang, of course, dared not reveal his identity. Leaving the inn, he looked up to the sky and sighed deeply, "This is what it means to be trapped by one's own scheme!"
Shang Yang was later executed by being torn apart by five chariots—a brutally cruel punishment where ropes tied to the convict's head and four limbs were attached to five separate chariots, which were then driven apart, ripping the person into five pieces, a sight too horrifying to bear.
Although King Huiwen had Shang Yang killed, he continued to implement Shang Yang's policies. As a result, Qin grew increasingly powerful, laying the economic and military foundation for Qin Shi Huang (Ying Zheng) to eventually unify the six states.