A special law or qualified majority law is a type of legislation in Belgium which requires a qualified majority in both chambers of the bicameral Belgian Federal Parliament to be adopted, amended or repealed. The Belgian Constitution determines which laws require a qualified or special majority. Special laws are primarily used in institutional matters and in matters concerning the competences of the communities and regions of Belgium. One of the best known examples is the Special Law of 8 August 1980 on the Reform of the Institutions.
A special law must be adopted by both the Chamber of Representatives and the Senate in accordance with Article 4, last paragraph, of the Belgian Constitution, which provides that a special law requires a majority of votes cast in both the Dutch-speaking and the French-speaking language group, on the condition that an absolute majority of the members of each language group is present, and the total number of votes in favour in both language groups must constitute a supermajority of two-thirds of the total number of votes cast.