Final answer:
A unilateral mistake in contract law does not free the mistaken party from their obligations unless the other party was aware of the mistake. This principle applies unless the error is known by the non-mistaken party who may have taken advantage of it.
Step-by-step explanation:
A unilateral mistake does not relieve the party who made the mistake from contract liability unless the other party knew of the mistake. In the context of contract law, when only one party to a contract is mistaken about a material fact, it is known as a unilateral mistake. This sort of mistake does not typically allow the mistaken party to void the contract unless the non-mistaken party was aware of the error and took advantage of it. If both parties are aware of the mistake, it may be possible to reform the contract to accurately reflect their agreement.