A contract that promises in exchange for an act is known as what type of contract?

A contract that promises in exchange for an act is classified as a unilateral contract. In this type of agreement, one party makes a promise that is contingent upon the performance of a specific act by another party. The defining feature of a unilateral contract is that only one party is bound to fulfill their promise when the other party performs the act.

For example, if one party offers a reward for the return of a lost item, the contract becomes enforceable when someone finds and returns the item; the promise of a reward is made in exchange for that specific act. The offeror is obligated to pay the reward once the act is completed, but the offeree is not required to perform the act; thus, the unilateral nature of the contract is highlighted.

In contrast, a bilateral contract involves mutual promises between two parties, where each party is both a promisor and a promisee. An express contract is one where the terms are clearly stated, whether orally or in writing, while an implied contract is formed based on the behavior and circumstances of the parties involved, reflecting their intentions even if not explicitly stated.