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 Ohio, contracts made for illegal purposes or against public policy are void and unenforceable. This means that if the subject matter of the contract is illegal, such as a contract for the sale of prohibited substances, or if it violates established public policy, neither party can seek legal recourse to enforce the contract. On the other hand, contracts that involve minors, mutual mistakes, or fraudulent misrepresentations are considered voidable. A minor in Ohio is typically someone under the age of 18, and contracts with minors can be disaffirmed by the minor before reaching the age of majority or within a reasonable time afterward. Contracts based on mutual mistakes can be rescinded if the mistake is material and affects the agreement's foundation. Contracts entered into because of one party's fraudulent misrepresentation can be voided by the disadvantaged party. However, these voidable contracts can be ratified if the disadvantaged party, upon reaching the age of majority, becoming aware of the mistake, or discovering the fraud, chooses to affirm the contract and continue with its performance.