New technologies have always been a critical component of military strategy and preparedness. One new technology on the not-too-distant technological horizon is lethal autonomous robotics, which would consist of robotic weapons capable of exerting lethal force without human control or intervention. There are a number of operational and tactical factors that create incentives for the development of such lethal systems as the next step in the current development, deployment and use of autonomous systems in military forces. Yet, such robotic systems would raise a number of potential operational, policy, ethical and legal issues. This article summarizes the current status and incentives for the development of lethal autonomous robots, discusses some of the issues that would be raised by such systems, and calls for a national and international dialogue on appropriate governance of such systems before they are deployed. The article reviews potential modes of governance, ranging from ethical principles implemented through modifications or refinements of national policies, to changes in the law of war and rules of engagement, to international treaties or agreements, or to a variety of other “soft law” governance mechanisms.