Which term refers to conditions that terminate a party's duty to perform?

The term that refers to conditions that terminate a party's duty to perform is "Condition Subsequent." In contractual terms, a condition subsequent is an event or circumstance that, if it occurs, can end an obligation that a party has under a contract. This means that the performance of the duty is no longer required if the condition subsequent takes place.

For instance, consider a contract where one party is obligated to perform services only as long as a specific condition is met, such as maintaining an operating license. If that license is revoked (the condition subsequent), that party's obligation to perform services ceases.

Other terms, like a condition precedent, relate to events that must occur before a duty to perform arises; thus, they establish obligations rather than terminating them. Discharge by novation involves substituting a new party into an existing contract, releasing the original party from its obligations, rather than terminating a duty through conditions. Substantial performance refers to a situation where a party has completed enough of the contractual obligations to warrant payment, but it does not address conditions that could eliminate the duty to perform entirely. Therefore, "Condition Subsequent" accurately captures the concept of terminating a duty to perform upon the occurrence of a specific event.