Act of God is the legal term used to denote events occurring outside of human control.  These include occurrences like sudden floods or other natural disasters, for which no one can be held responsible.   The legal concept of Act of God has implications in both Contract Law and in Tort Law.

Under the U.S. legal system, failure to deliver goods sold may be excused by an “act of God” if the absence of such act was a “basic assumption” of the contract, but has made the delivery commercially “impracticable”.

The term “act of God” is most notable in insurance policies because insurance companies mostly make this an exception in their coverage.  In other words, most standard insurance contracts state that they will not entertain claims for damage caused by acts of God, which, sadly, includes floods.  However, if the insurance contract specifically provides coverage for unforeseen natural calamities then the insurance company would have to provide coverage.  But most property insurance coverage — like those that cover cars and houses — usually have an Acts of God clause that exempts the insurance company from liability.