There are certain factors which affect the existence or validity of the contract. Although treatment in depth is beyond the scope of this Lesson, students should be aware of such factors. They include: Duress and Undue Influence which renders the contract voidable at the option of the party who was coerced or influenced, as his consent to the making of the contract was not freely given. Incapacity A contract will be void if one party is not recognised as being capable of entering into the contract. This may occur in, for example, the case of drunks, minors or lunatics. Unenforceable Contracts. Where the contract does not comply with required formalities. Force Majeure relieves the party to the contract from responsibility for non-performance or varied performance in circumstances which are entirely beyond his control. Void and Illegal Contracts. A contract will be void if, for example, it is restraint of trade. A contract will be illegal if it is to perform an unlawful act. The fact that one party to a contract acted under a mistake does not necessarily affect the validity of the contract. A contract is only void for mistake where the mistake is such that there was never any real agreement between the parties, or, if there was, if the agreement was only formed out of the same common mistake by both parties on some vital issue.