An attempted contract that is made for an illegal purpose or that is against public policy cannot be enforced by either party and is void. In contrast, a contract that is made by a minor (usually under age 18), or that is based on a mutual mistake, or that was made on the basis of a fraudulent misrepresentation by one party, is voidable and may be rejected by a party who was at a disadvantage when the contract was made. A voidable contract may also be ratified and accepted by such a party—after a child reaches the age of majority (usually 18), or the parties become aware of their mutual mistake, or a party learns of the other party’s misrepresentation and proceeds with performance of the contract.

In Massachusetts, a contract created for an illegal purpose or against public policy is considered void and unenforceable by law. Neither party can seek legal recourse to enforce such a contract. On the other hand, contracts involving minors (typically under the age of 18), those based on mutual mistakes, or those formed under fraudulent misrepresentation are categorized as voidable. This means that the disadvantaged party has the option to either reject or ratify the contract. For instance, a minor may choose to ratify a contract upon reaching the age of majority, which is usually 18. Similarly, parties who realize a mutual mistake or discover a fraudulent misrepresentation can decide to continue with the contract's terms or to rescind it. It's important to note that the specifics of contract law can be complex, and an attorney can provide guidance on the enforceability or options for rescission of a contract under Massachusetts law.