It’s a trope as old as video games themselves — the sentry gun, an unfeeling mechanical contrivance that fires on unsuspecting players as soon as they come within range. These enemies have been a staple in thousands of games, causing gamers of every stripe to throw down their controllers in frustration. Science fiction as well is full of robotic killers like the Terminator who wantonly disregards the first of law of robotics, as enshrined by author Isaac Asimov’s I, Robot – that a robot “may not injure a human being.”But with today’s technology, with our electro-optical devices, advanced computers and robotic systems it is possible to bring these kinds of autonomous weapons systems into reality. And for that reason a team at Human Rights Watch has launched the Campaign to Stop Killer Robots.Laugh all you like. It’s a subject that even Stephen Hawking is thinking about.Mary Wareham, advocacy director of HRW’s arms division, is deadly serious about stopping killer robots before it’s too late. There’s a sense in Washington, especially in the defense community, that these things are inevitable. “There’s a sense in Washington, DC — especially in the defense community, that these things are inevitable,” Wareham told Polygon. “Some…