Generally speaking in the United States minors are allowed to disaffirm contracts (there are some exceptions).
But what if the minor tricks the other party by misrepresenting himself to be an adult? Is it fair to allow the minor to walk away from the contract?
Different states take different approaches. Some states provide that a minor who deceives the other party is obligated under the contract. However, some of these states require that the other party reasonably believed that the minor was an adult at the time. In those states if the other party knows or should know that the minor is trying to trick him, then the minor will be allowed to disaffirm the contract.