In the Federal Republic of Germany, as is officially called, the 16 German states (Länder) and the federal state (Bund) have different jurisdictions. In the past, gambling and sports betting (with the exception of horse betting) has been regulated by the states (however, the Federal Constitutional Court expressly mentioned the possibility of a new regulation by the Federal Parliament, as sports betting has to be regarded as a business matter).
Matters, falling under the jurisdiction of the states, can be regulated not only by normal state acts, but also by interstate treaties. The idea behind an interstate treaty, that is a treaty between all 16 states, is is the creation of uniform law, without giving the jurisdiction to the federal state. Interstate treaties are quite common to regulate media matters, e.g. Interstate Treaty on Broadcasting (Rundfunkstaatsvertrag) and Interstate Treaty on Media Services (Mediendienste-Staatsvertrag). Interstate treaties have to be ratified by the state parliaments and are regarded as state law.