Free consent in contract law means that the parties involved willingly agree to the terms of a contract without any undue influence, coercion, misrepresentation, fraud, or mistake. For a contract to be valid, the consent of the parties must be voluntary, genuine, and free from any factors that might impair their ability to make an independent decision. If consent is not freely given, the contract may be voidable, and the affected party may have the option to rescind the agreement.