The current paper aims at an analysis of ths state of exception or exceptional legislation, incorporating to studies coming from political theory, certain distinctions from the law that might contribute to a clarification of the debate. This in view that to-day we confront a "normalized" state of exception, since exceptions are incorporated into juridical ordering. This typo of legislations shows the relation between norm and decision and/or between norm and power, and in the juridical theory could be analyzed through figures like the tacit alternative clause of Kelsen or the relation between validity and efficacy of norms.