Which condition invalidates an enforceable contract?

The condition that invalidates an enforceable contract is when the purpose of the contract is illegal. Contracts must have a lawful objective to be enforceable in a court of law. If a contract is created for illegal purposes—such as agreements to commit a crime or violate public policy—it is void from the outset. Thus, it cannot be enforced by either party, as the legal system does not support illegal acts. This fundamental principle ensures that contracts exist in a framework of legality and protect societal interests.

Understanding how legality impacts contract validity is key, as it determines whether the doors of legal recourse are open or closed for the involved parties. While other factors, such as clarity of terms and mutual agreement, can affect the enforceability of a contract, they do not inherently nullify a contract like an illegal purpose does.