While an undefeated contract is often considered unfeasible, a contract may be considered questionable if the agreement is questionable, but the circumstances of the agreement are questionable. This includes agreements entered into where a party has withheld information or deliberately provided inaccurate information. Failure to disclose things like the law or misplace information may make the contract countervailable, but does not automatically invalidate it. In cases where one party may terminate the contract due to unlawful or unfair (countervailable) acts of the other party, the contract or agreement is cancelled. The contract may also be considered inconclusive when an illicit asset or unlawful consideration is included in the contract. This may include the promise of sex, an illegal substance, or something else that causes either party to break the law. Figure: A driver of a tram company agreed to be bound by the general manager of the company with regard to a count and salary for the current month in the event of a breach of the rules. The agreement was found to be valid. Invalid contracts can occur if one of the parties is not able to fully understand the impact of the agreement. For example, a mentally disabled person or a drunk person may not be consistent enough to adequately record the parameters of the agreement, which makes it void.. .