High Quality Content by WIKIPEDIA articles! An act is an instrument that records a fact or something that has been said, done, or agreed. Acts generally take the form of legal instruments of writing that have probative value and executory force. They are usually accepted as self-authenticating demonstrative evidence in court proceedings, though with the precarious status of notaries public and their acts under common law, this is not always so. Common types of acts are legislative, judicial, and notarial acts.