What type of agreements are unenforceable under contract law?

Agreements without consideration are unenforceable under contract law because consideration refers to something of value that is exchanged between the parties involved in a contract. For a contract to be valid and enforceable, there must be a promise that involves some form of consideration from both sides. If there is no consideration, the agreement lacks the necessary legal foundation and is essentially a one-sided promise, which the law does not recognize as a binding contract. This ensures that both parties have a stake in the agreement, reflecting mutual benefits and obligations.

Other types of agreements, like oral agreements, can still be enforceable in certain circumstances, although they may face challenges in proving their existence or terms in court. Written contracts are generally seen as more reliable forms of agreements but are not necessarily unenforceable without consideration. Bilateral contracts involve promises from both parties and are typically enforceable unless they also lack consideration or meet other specific legal criteria for unenforceability.