Who doesn’t like mock sword fights? But too often, they devolve into arguments over whether a hit “counts” or not. That’s where Sabertron comes in. They create foam swords that tally the score, tracking body hits as well as blade-on-blade strikes. Check it out in this video, created by our partner Portico.

Popular Science went to the 2015 Bay Area Maker Faire to find the craziest, coolest, and most mind-blowing projects. Watch all our Maker Faire videos here. Or view the full-length show at