How is a unilateral contract established?

A unilateral contract is established when one party makes a promise in exchange for the performance of a specific act by another party. In this type of contract, only one party is bound to fulfill an obligation, which occurs when the second party completes the act requested. For example, if someone offers a reward for the return of a lost item, the contract is formed when the person finding the item performs the act of returning it, thereby accepting the offer.

The focus on performance rather than a reciprocal promise distinguishes unilateral contracts from bilateral contracts, where both parties make promises to each other. The requirement that it can be established without a written agreement or mutual consent underlines the nature of unilateral contracts as being completed through the act itself rather than through negotiation or exchange of promises.