estoppel: a standalone construct

Sir Edward Coke, in his 1628 Commentary upon Littleton (the First Institute), gave the classic definition of estoppel as a rule by which a person is concluded by their own act or acceptance from denying the truth of what they earlier stated, a doctrine already long settled in the English common law. In plain terms, estoppel bars (estops) a party from asserting a fact or legal position that contradicts what that party previously stated, admitted, or established, once another party has reasonably relied on the earlier position to their disadvantage. The best known modern extension is promissory estoppel, set out by Denning J in Central London Property Trust Ltd v High Trees House Ltd (1947), which held that a promise meant to be acted on, and in fact acted on, can bind the promisor even without the consideration that ordinarily makes a promise enforceable. In the United States the same reliance principle is stated in Section 90 of the American Law Institute's Restatement of Contracts (1932), under which a promise binds when the promisor should expect it to induce action or forbearance and it does so, if injustice can be avoided only by enforcing it. As a landmark of private law, estoppel spans several recognised forms, including equitable, promissory, and collateral (issue) estoppel, and operates across contract, property, and procedure as a protection for reliance on prior conduct rather than as a freestanding claim.[1][2][3]

Unit

A legal doctrine barring inconsistent assertion, raised within a case rather than measured on a scale

Recovery means

Not applicable

Measured by

Identified by courts from its elements: a clear representation or promise, reasonable reliance on it by another party, and resulting detriment or change of position