A contract that entails the payment of an amount of money in exchange for performance of a promised act. The potential performer (offerree) expressly accepts to carry out a piece of work or task if a beneficial party (offeror) stands ready to pay a specific amount upon fulfillment. In a unilateral contract, there is an express offer that payment will be made, conditional on a party’s performance. Examples of unilateral contracts include a reward or a contest.

In a unilateral contract, the offeror may revoke or withdraw the offer before the offeree’s embarks on performance. Typically, the revocation have to be expressly communicated to the offerree.

The opposite of a unilateral contract is a bilateral contract.