Students at Stanford have created a robot that you can fight with a foam lightsaber. From IEEE Spectrum:
If there was one bad thing about those lightsaber-wielding robots from Yaskawa that we saw at ICRA, it was that you couldn’t bust out your own lightsaber and jump in the middle of the fight. A paper also presented at ICRA showed us robots swinging swords in simulation against humans, but without much in the way of physical combat. Now a student project at Stanford has put these two brilliant ideas together and come up with “JediBot,” a robot arm that will actually try to kill you with a foam sword.
Is it fun to design a robot that can fight humans? No doubt.