Impossible Condition Law and Legal Definition

Impossible condition is a condition precedent or subsequent in a contract which, at the time when the contract is entered into, purports to bind a party to do that which is absolutely impossible in itself.

Impossible conditions cannot be performed; and if a person contracts to do what at the time is absolutely impossible, the contract will not bind him, because no man can be obliged to perform an impossibility; but where the contract is to do a thing which is possible in itself, the performance is not excused by the occurrence of an inevitable accident or other contingency, although it was not foreseen by the party, nor was within his control. [Jones v. United States, 96 U.S. 24, 29 (U.S. 1878)].