The author reviews the English common law of forgery as well as the Forgery Act 1913. He observes that early law did not adequately define what constitutes forgery and it limited forgery to the falsifications of writings and documents. The Forgery and Counterfeiting Act 1981, on the other hand, defines its terms and deals with new forms of forgery. By saying that what must be 'false' is an instrument that tells a lie about itself, the new law expands forgery beyond the consideration of paper documents to include high technology methods of storing and recording information as well as trade and hall marks. The author notes that the expanded concept of forgery in the 1981 act provides the art world with increased protection from commerce in art fakes. Additionally, the 1981 act criminalizes the acts of those who would profit improperly from another's hard-won good will by copying trade or hall marks. 9 footnotes.