The principles of legality in criminal law determine numerous requirements both for the legislator creating criminal statutes and for judges as well who decide criminal cases. One of the most important demands of legality is the principle of maximum certainty according to which the state must establish a system of criminal law in which the wording of the statutes are clear, precise and understandable for the citizens; and judges are able to interpret criminal rules without making arbitrary decisions. In the Hungarian legal system the demands of maximum certainty are represented by the principle of nullum crimen sine lege. This principle is called the „clarity of norms” doctrine in the practice of the Constitutional Court of Hungary (HCC) which is entitled to strike down criminal statutes which do not meet its requirements. The aim of this paper is to argue for the claim that the „clarity of norms doctrine” and the concept of certainty in criminal law is based mostly on considerations about the plain meaning of words and texts and lack a coherent theoretical background in the decisions of the HCC and in judicial practice as well. The author offers a more complex and coherent conception of certainty stating that its requirements relate not only to linguistic considerations but also to thinking over the moral and political values of criminal law as well.