Which legal principle allows a party to enforce a promise when it has relied on that promise to its detriment?

Promissory estoppel is the legal principle that allows a party to enforce a promise when it has relied on that promise to its detriment. This doctrine is rooted in fairness and aims to prevent injustice when a party makes a promise that another party relies upon, leading to a change in position or circumstances.

For promissory estoppel to apply, there must be a clear and definite promise made by one party, reasonable reliance by the other party on that promise, and the reliance must result in a detriment or change in position. Essentially, the principle serves to hold the promisor accountable when their promise leads someone to take action or make decisions that they wouldn't have made otherwise, thereby creating a situation where it would be inequitable to allow the promisor to back out.

The other options relate to distinct legal concepts. The statute of frauds involves the requirements for certain contracts to be in writing to be enforceable. Equitable estoppel generally prevents a party from asserting something contrary to what is implied by a previous action or statement if it would unfairly harm another party who relied on the original representation. Implied contracts are formed by the behaviors and actions of the parties involved rather than through explicit written or spoken agreements. None of these principles address