R2d § 90
Promise Reasonably Inducing Action or Forbearance
(1) A promise which the promisor should reasonably expect to induce action or forbearance on the part of the promisee or a third person and which does induce such action or forbearance is binding if injustice can be avoided only by enforcement of the promise.
Professor's notes
Elements: (1) a promise; (2) the promisor should reasonably expect to induce action or forbearance; (3) the promise does in fact induce such action or forbearance; (4) injustice can be avoided only by enforcement; (5) the remedy may be limited as justice requires.
Ricketts v. Scothorn operationalizes elements (2)-(4): grandfather's promise reasonably induced the granddaughter to quit work; she did.
Conrad v. Fields shows the modern employment-promise application: tuition-paid promise relied on through law school.
Common misunderstanding: students think § 90 substitutes for consideration in any unfulfilled-promise case. It does not. The reliance must be reasonable, foreseeable, AND such that nothing short of enforcement avoids injustice. Element (5) is also missed: courts may enforce only the reliance interest, not full expectation. § 90 is the central reliance-based exception to § 17's bargain requirement.
Cases that operationalize this rule
Text
R2d § 90. Promise Reasonably Inducing Action or Forbearance.
(1) A promise which the promisor should reasonably expect to induce action or forbearance on the part of the promisee or a third person and which does induce such action or forbearance is binding if injustice can be avoided only by enforcement of the promise. The remedy granted for breach may be limited as justice requires.
(2) A charitable subscription or a marriage settlement is binding under Subsection (1) without proof that the promise induced action or forbearance.