This document defines and provides examples of contingent contracts. A contingent contract is an agreement to perform or not perform an action depending on whether some uncertain future event does or does not occur. The performance of the contract depends on a collateral, or unrelated, future event. The document outlines five rules regarding contingent contracts: 1) a contract contingent on an uncertain future event cannot be enforced until the event occurs, 2) a contract contingent on a future event not occurring can be enforced if the event becomes impossible, 3) if a contract depends on a person's future actions, it becomes impossible if they act in a way that prevents the contingency, 4) a contract contingent on an event within a time period becomes void if the event does not occur