According to Kelsen, the principle of effectiveness-legal norms are valid only because they are effective; that is, people generally obey them and governments enforce them. If a legal system becomes ineffective, as in a revolution, its norms lose their validity.

During revolution, the old Basic Norm is replaced by a new one, if the new system finds acceptance. Replacing monarchy by republic is a good example; it assumes the constitution of the republic as the new Basic Norm, supposing this is generally accepted.

It also extends to international law; national laws acquire a residual degree of legitimacy because they form part of an efficient and respected international system. The Basic Norm here would be the commitment to upholding international treaties and obligations and so creating a harmonious universal legal system.