The German federal election system regulates the election of the members of the national parliament, called Bundestag. According to the principles governing the elections laws, set down in Art. 38 of German Basic Law, elections are to be universal, direct, free, equal, and secret. Furthermore, the German Basic Law stipulates that Bundestag elections are to take place every four years and that one can vote, and be elected, upon reaching the age of 18.