PREEXISTING-DUTY RULEpreexisting-duty rule. Contracts. The rule that if a party does or promises to do what the party is already legally obligated to do ¡ª or refrains or promises to refrain from doing what the party is already legally obligated to refrain from doing ¡ª the party has not incurred detriment. ? This rule’s result is that the promise does not constitute adequate consideration for contractual purposes. For example, if a builder agrees to construct a building for a specified price but later threatens to walk off the job unless the owner promises to pay an additional sum, the owner’s new promise is not enforceable because, under the preexisting-duty rule, there is no consideration for that promise. ¡ª Also termed preexisting-legal-duty rule. [Cases: Contracts 75. C.J.S. Contracts ¡ì 120.]
What is the Chinese interpretation of PREEXISTING-DUTY RULE?