Zusammenfassung The article examines - with a multitude of examples - the complex method, in which criminal rules evolve in contemporary law. This happens in a continuing process, to which - in addition to the citizens - the legislator, criminal courts and the Federal Constitution Court contribute. The courts are not confined to applying the laws enacted by the legislator, which would be in accordance to a simple model of the separation of powers. The laws rather have to undergo an on-road test by the courts, during which they can prove to be practicable, difficult to handle or not practicable at all and therefore void. The legislator for his part takes note of the judicature and that often brings him to make further decisions. These include the abstaining from establishing new laws, the (plain or modifying) reception of some jurisdictional opinions, the changing of laws against their jurisdictional interpretation and the transformation of other than the jurisdictionally interpreted laws. All in all the criminal law proves to be a good example for the incremental evolution of norms, which occurs in a specific division of labour between the legislator, the criminal courts and the Federal Constitution Court.