Preexisting Duty Rule

A promise to perform an existing legal duty is not consideration unless new or different consideration is provided.

Representative cases

• Panasonic Communications & Systems Co. v. State, Department of Administration, Bureau of Purchases 1997 ME 43 · Supreme Judicial Court of Maine
• Pederson v. Arctic Slope Regional Corporation 421 P.3d 58 · Alaska Supreme Court
• Jankowski v. Monclova-Maumee-Toledo Joint Economic Development Zone Board of Directors 185 Ohio App. 3d 568 · Ohio Court of Appeals

Related Formation rules

• Contract DefinedA contract is a legally enforceable promise formed by mutual assent and consideration.
• Offer RequirementsAn offer is a manifestation of intent to be bound with definite terms communicated to an identifiable offeree.
• Termination of OfferOffers terminate by revocation, rejection, lapse, death, or destruction of subject matter.
• Option ContractsAn option is irrevocable when supported by consideration for a promise to keep the offer open.
• Firm Offers (UCC)A merchant’s signed writing assuring it will remain open is irrevocable for the period stated, up to 3 months.
• Acceptance: Mirror RuleUnder common law, acceptance must mirror the offer; additional or different terms are counteroffers.
• Acceptance by PerformanceUnilateral contracts are accepted only by complete performance.
• Acceptance by PromiseBilateral contracts are accepted by a return promise or beginning performance.

Part of Contracts on Core Legal Rules — foundational MBE-tested principles with primary-source citations.