Promissory estoppel

Promissory estoppel is an equitable doctrine to require payment in the absence of a contract, if:

defendant promised something to the plaintiff, upon which plaintiff could reasonably rely;

plaintiff did in fact rely on the promise; and

plaintiff was harmed as a result, i.e., plaintiff relied to his detriment.

This was codified at Section 90 of the Restatement of Contracts. Traditional defenders of contract law opposed this approach because it gives a court discretion to award relief even if there is no contract.

This approach exemplifies a movement against the strict view of contract. Professor Grant Gilmore applauded judicial erosion of contract principles in his famous work, The Death of Contract.