In Pennsylvania, in order to enforce a force majeure clause as an excuse for non-performance, the event alleged as an excuse must have been beyond. After making sure PA law allows for declaring force majeure, you need to establish causation.Force majeure clauses, whether in construction contracts or other types of contracts, are meant to address events that could not reasonably have been foreseen. A Force Majeure Clause is a legal concept that allows one party to a contract to suspend, excuse, or terminate contractual obligations. Force Majeure: Unforeseeable circumstances that prevent someone from fulfilling the contract. This paper discusses when a party may have a legal defense if it elects to not perform contract obligations. As explained in that article, force majeure is a contractual term that only applies if it is included in the governing contract. Guage in the contract. A force majeure clause can excuse one or both parties from fulfilling a contract's terms when an unforeseeable event occurs.