I am allegedly holding a cardboard gun, but I can’t seem to get my hand around the trigger. A guiding hand moves my arm and a voice from somewhere tells me to walk forward.

He writes that Marines trained the Pentagon's Defense Advanced Research Projects Agency's robots. The robots, trained to identify humans, were fooled by Marines doing somersaults and hiding in boxes.

Solid Snake using a cardboard box as a disguise in Metal Gear Solid. DARPA was quickly humbled. Scharre writes that all eight Marines were able to defeat the robot using techniques that could have ...