What type of mistake renders a contract void?

A mutual mistake regarding the subject matter of a contract occurs when both parties are mistaken about an essential fact that fundamentally affects the agreement. This type of mistake can make the contract void because it means that the parties lack a true meeting of the minds about what they are agreeing to. If both parties have a misunderstanding about a significant aspect of the contract—such as the existence, identity, or nature of the subject matter—then the contract is unenforceable.

In contrast, mutual mistakes about value may not render a contract void because both parties understood the subject matter but simply misjudged its worth. Unilateral mistakes about intent occur when one party is mistaken while the other party is aware of the mistake; in such cases, the contract remains valid unless certain specific criteria are met. Therefore, the primary reason that mutual mistakes regarding the subject matter are pivotal is that they directly affect the validity of the contract itself, leading to its void status.