The article deals with the translation of rules with particular reference to German Patentgesetz. It is divided into five chapters. The first gives an overview of the most recurrent cases of legal translation (e.g. one legal system-various official languages; two legal systems-various official languages and so on). The second chapter deals with the fundamental elements of translation strategy in the legal sector (e.g. function, function change, text type, legal language, concept of parallelism). The third chapter gives a definition of the text type rule and discusses the translation of the German Patentgesetz into Italian at the macro and microlevel shedding light upon the crucial points of the translation process (particularly dislocation of syntagmata and sentences; obviously terminological problems as well). The conclusions contain a discussion of the translation of a Paragraph of the Patentgesetz carried out by three machine translators at two different times.