What characteristic of a contract requires both parties to meet certain conditions for enforceability?

The characteristic of a contract that requires both parties to meet specific conditions for enforceability is known as conditional. A conditional contract includes provisions that specify certain events or actions that must occur before the contract becomes effective or before the obligations within it are required to be performed. This means that the enforceability of the contract is dependent on the fulfillment of these specified conditions.

For instance, a life insurance policy might be conditional upon the insured providing accurate information during the application process; if the conditions are not met, the contract may not be enforceable. This nature is essential in distinguishing contracts where both parties have obligations contingent upon certain events from those that do not have such requirements.

The other characteristics mentioned, such as unilateral, adhesion, and executory, do not imply the same dependence on conditions for enforceability. A unilateral contract involves one party making a promise that is only binding upon the completion of an action by the other party. Adhesion contracts are typically standard form contracts created by one party, where the other party has little negotiating power, and executory contracts refer to those that have not yet been fully performed by either party.