What is the primary legal implication of a unilateral contract?

In a unilateral contract, only one party is obligated to perform their part of the agreement. This type of contract is often seen in scenarios where one party makes a promise in exchange for an act from another party. For instance, if someone offers a reward for a lost pet, they are legally bound to pay the reward once the pet is found, but the person finding the pet is not obligated to do anything in return until the act is performed.

The nature of unilateral contracts inherently leads to one-sided obligations, which distinguishes them from bilateral contracts, where both parties commit to fulfilling their respective duties. This understanding is pivotal, as it allows individuals to engage in agreements with the expectation of fulfilling specific obligations without requiring mutual promises.

Other options presented do not capture the essence of unilateral contracts: a requirement for both parties to perform does not reflect the structure of unilateral agreements; a writing requirement may exist for certain types of contracts but is not a defining aspect; and while unilateral contracts can generally be enforced in court, they do not inherently lack enforceability.