Unmanned warfare devices may change the way wars are fought and perceived. Conflicts may no longer be man-to-man battles but become more and more robotized. The current trend toward developing technology in the field of robotic warfare will undoubtedly continue. As of today, there is no specific international treaty or conventional provision prohibiting or regulating the use of unmanned means and methods of war. Without a rapid evolution of the legal framework, there will be a real hiatus between the laws and the reality of conflicts. This article examines the core regulatory challenges triggered by the emergence of new types of autonomous or semi-autonomous warfare devices. Robots present some unquestionable advantages, but also entail great risks regarding their potential capacity to create collateral damages among civilian populations. Besides the crucial question whether robots will be able to respect the IHL principles of distinction and proportionality, the issue of accountability and responsibility for breaches of the laws of war must also be a priority for lawmakers and regulators. The increasing dehumanization of war, coupled with the uncertainty on the ethical and legal limits applicable to the design, development, acquisition, transfer and deployment of military robots, makes regulation of unmanned warfare devices a compelling necessity.