Whether weapons that rely on artificial intelligence for their targeting and use of force are a danger or a potential benefit to humanity is sharply disputed. This chapter argues that autonomous weapons systems do not, per se, violate any branch of international law. But, as is the case with any weapons, they must comply with international humanitarian law in any armed conflict and with international human rights law at all times. In armed conflict, this requires that autonomous weapons systems be able to distinguish between military objectives and civilians and civilian objects and in any event must not cause excessive incidental civilian harm that is reasonably foreseeable to a human commander. The United Nations Secretary-General has called on States to conclude a treaty to prohibit lethal autonomous weapon systems that function without human control or oversight by 2026. This target will not be met.