Act of God

In common law systems, an Act of God (Latin: vis major or damnum fatale in Scots law) refers to a sudden, natural occurrence that no reasonable human foresight, care, or skill could have anticipated or prevented. Classic examples include earthquakes, floods, lightning strikes, hurricanes, and tsunamis. The doctrine functions primarily as a defense: a party who would otherwise be liable for breach of contract or negligence may escape liability by proving that the loss was caused exclusively by such an event, without contributing human fault.

The English case Nichols v. Marsland (1876) is often cited as a foundational authority, where unprecedented rainfall that breached artificial reservoirs was held to be an Act of God, exonerating the defendant. Courts since have narrowed the doctrine: in Greenock Corporation v. Caledonian Railway (1917), the House of Lords held that even severe rainfall may be foreseeable in regions where it occurs periodically, limiting the defense's scope.

In modern contract drafting, the concept is usually absorbed into force majeure clauses, which list specific triggering events and the consequences (suspension, extension, or termination of obligations). Insurance policies likewise distinguish covered "natural perils" from excluded Acts of God, though the boundary varies by jurisdiction and policy.

Civil law systems use analogous but not identical concepts — force majeure in French law and höhere Gewalt in German law — which typically require the event to be external, unforeseeable, and irresistible. International commercial instruments such as the UN Convention on Contracts for the International Sale of Goods (CISG), Article 79, provide a related exemption when performance is prevented by an impediment beyond a party's control.

For MUN delegates and researchers, the term most often arises in debates over disaster relief obligations, climate-related liability (where increasing predictability of "natural" events erodes the defense), and sovereign debt or trade contract disputes following catastrophes.