Restatement Second of Contracts § 154
When a Party Bears the Risk of a Mistake
A party bears the risk of a mistake when
- the risk is allocated to him by agreement of the parties, or
- he is aware, at the time the contract is made, that he has only limited knowledge with respect to the facts to which the mistake relates but treats his limited knowledge as sufficient, or
- the risk is allocated to him by the court on the ground that it is reasonable in the circumstances to do so.
Copyright, The American Law Institute