Chinese Idiom: 万无一失 (Wan Wu Yi Shi)
English Translation: Absolutely Foolproof
pīn yīn: wàn wú yī shī
Idiom Meaning: This idiom describes a situation or plan that is extremely reliable and guaranteed to succeed without any possibility of mistake.
Historical Source: even Treatises (《七发》) by Mei Cheng (枚乘) from the Western Han Dynasty; also mentioned in Records of the Grand Historian: The Biographies of the Hegemon-Kings of the Huaiyin (《史记·淮阴侯列传》).
Idiom Story:
During the tumultuous period of the Chu-Han Contention, the famous general Han Xin had achieved a major victory by defeating and capturing the troops of Xiang Yu, a rival leader. This defeat caused Xiang Yu significant distress, prompting him to send emissaries, including the diplomat Wu She, to negotiate peace with Han Xin. Xiang Yu proposed that they form an alliance to jointly resist Liu Bang and divide the empire among themselves.
Despite these overtures, Han Xin remained loyal to Liu Bang, the Han Emperor, and refused the offer. Wu She’s mission ended in failure, and Han Xin’s unwavering allegiance was clear.
The renowned debater Kuai Tong, recognizing the pivotal role Han Xin played in the power struggle, tried to persuade him to reconsider the division of power between Liu Bang, Xiang Yu, and himself. Kuai Tong used divination as a tool, claiming that understanding a person’s status, emotional state, and decision-making process could predict outcomes with certainty. He stated, “贵贱在于骨法，忧喜在于容色，成败在于决断，以此参之，万不失一,” which translates to: “Nobility and status depend on the bone structure; emotions are reflected in the facial expression; success or failure relies on decisions. By analyzing these aspects, the result is guaranteed to be accurate, with no chance of error.”
Despite Kuai Tong’s efforts to persuade Han Xin with this method, Han Xin’s decision remained unchanged, reflecting his firm stance and strategic calculations.
The idiom “万无一失” originated from the assurance of a foolproof plan based on careful analysis, and it has since come to signify absolute certainty and reliability in any undertaking.
