What does supervening impossibility refer to in contract law?

Supervening impossibility refers to a situation in contract law where events occur after the formation of a contract that render it impossible for one or both parties to perform their obligations. This concept acknowledges that unforeseen circumstances can arise that fundamentally change the nature of performance, removing the feasibility of fulfilling the contract entirely.

For instance, if a party agrees to deliver goods but a natural disaster destroys the goods before they can be delivered, this unforeseen event would be a classic case of supervening impossibility. The original agreement is no longer viable because the necessary conditions for performance have changed drastically since the contract was made.

The other options do not accurately capture the essence of supervening impossibility. While an unexpected event that makes it difficult to perform could suggest a degree of challenge, it does not necessarily reach the level of impossibility required to invoke this legal principle. Similarly, a natural end of a contract doesn't pertain to supervening impossibility, and a previously existing condition that changes reflects more about modifications in terms of the contract rather than the absolute impossibility of fulfilling it due to new events.