Promissory estoppel is an equitable theory of recovery that permits enforcement of a promise when one or more elements necessary to create an enforceable contract are missing.

The elements of promissory estoppel are generally: (1) a promise; (2) foreseeability of reliance by the promisor; (3) substantial and reasonable reliance by the promisee to its detriment; and (4) enforcing the promise is necessary to avoid injustice.

In Indiana, promissory estoppel serves as a legal remedy that allows a court to enforce a promise even when certain elements of a formal contract are absent, provided specific conditions are met. The doctrine is based on the principles of equity and fairness, aiming to prevent injustice that would result from not enforcing the promise. The elements required for promissory estoppel in Indiana include: (1) a clear and definite promise, (2) the promisor's expectation or foreseeability that the promisee will rely on the promise, (3) actual and reasonable reliance on the promise by the promisee to their detriment, and (4) a finding by the court that enforcement of the promise is necessary to avoid an injustice. If these elements are satisfied, Indiana courts may compel the promisor to fulfill their promise or provide compensation for the promisee's reliance. This doctrine is particularly relevant in situations where a formal contract does not exist or is unenforceable due to some deficiency, but where one party has relied on the other's promise to their detriment.