A promise in exchange for an act describes which type of contract?

A promise in exchange for an act characterizes a unilateral contract. In a unilateral contract, one party makes a promise that is contingent upon the performance of an act by another party. For example, if someone offers a reward for the return of a lost pet, the offeror is making a promise to pay upon the performance of the act of returning the pet. The contract is only formed when the act is performed, meaning that the party who is accepting the offer does not need to respond or promise anything in return; they simply need to complete the action specified.

In contrast, a bilateral contract involves mutual promises where both parties agree to perform certain obligations in exchange for the other’s performance. An executory contract refers to a contract that has been agreed upon but for which the terms have not yet been fully completed — this is not related to the concept of a promise in exchange for an act. A void contract is one that is not legally enforceable, either due to missing essential elements of a valid contract or being against public policy, but this does not apply in the context of promises and acts.