An Act of God is a natural force outside of human control (such as an earthquake, tsunami, or hurricane), and may relieve a party or parties to a contract or agreement from having to perform their obligations. Such Acts of God are often addressed in a force majeure clause, which typically appears near the end of the contract or agreement. A force majeure clause may also excuse a party's performance of its obligations for other reasons beyond its control, such as unavailability of products, riots, civil unrest, pandemics, and terrorism.

In Wisconsin, as in many jurisdictions, an 'Act of God' refers to any event that is outside the realm of human control and cannot be predicted or prevented by reasonable measures. Such events can include natural disasters like earthquakes, tsunamis, or hurricanes. Wisconsin law recognizes that these unforeseen events may interfere with the ability of parties to fulfill their contractual obligations. Force majeure clauses are contractual provisions that parties include to protect themselves from liability for non-performance in the face of such uncontrollable events. These clauses typically outline the types of events that qualify as force majeure and may include not only natural disasters but also other circumstances such as pandemics, riots, civil unrest, and terrorism. The specific language of the force majeure clause will determine whether a party is excused from performance and under what conditions. If a contract does not contain a force majeure clause, parties may still invoke the common law doctrine of impossibility or impracticability of performance, but this is a more challenging defense that requires a higher burden of proof.