Unmanned systems (UMS) have become firmly and widely established in many armed forces. They offer cost, effectiveness and safety benefits in key areas of the military capability spectrum, or open up new options on the battlefield. These include, for example, longer-duration missions compared to manned systems, reduced risk to personnel, and the possibility of comprehensive reconnaissance in high-risk operational environments. The development of UAS is linked to advances in numerous fields of technology and opens up economic potential that extends beyond the military sphere. However, at least since the thousands of deployments of airborne armed drones in Iraq and Afghanistan, UAS have also been associated with challenges relating to security, arms control policy and international law. The TAB report describes the state of development and military use of unmanned systems in the air, on land and at sea in a national and international context, and provides an overview of current and future key technologies for the development of UMS. Furthermore, it addresses the economic dimension of unmanned systems in the defence and civilian sub-markets of the national and international economic system, in order to analyse the civilian innovation and application potential of UMS on this basis. The report also situates unmanned systems within the legal framework established by arms and arms export control treaties as well as international legal norms, and takes stock of the applicable treaties with regard to their relevance for UMS, in order to finally highlight the need for information and discussion at both the political and societal levels.