Wirtz, Richard S.
Impracticability and frustration of purpose are important exceptions to the principle that contracts must be performed, come what may. At common law, the general rule is that the promisor bears the risk that a contract may become more burdensome or less desirable to her as a result of changes in circumstances for which she did not plan. But when an extraordinary circumstance renders a promised performance so different from what was to be expected that it changes the essential nature of that performance, the courts hold that justice requires a departure from the general rule. The law of impracticability and frustration, as it has evolved under section 2-615 of the Uniform Commercial Code (UCC), and section 261 of the Restatement (Second) of Contracts (Second Restatement), is more confusing than it should be and frequently and unnecessarily fails to achieve its purpose. Some easily implemented changes to the rules will render outcomes in these cases more predictable and more just.