It’s back-to-school time on college campuses across the country, and for students that means kick-off events and lots of free stuff from local vendors eager to market themselves. At one such event on the campus green of Kennesaw State University (KSU) in Cobb County, Ga., outside Atlanta, many of those students –- including incoming freshman -– received a plastic cup, a bottle opener and a ping pong ball, all printed with the Domino’s Pizza logo and the nearest store’s phone number. If you’ve been out of the college scene for a while, this may seem a strange collection of items. But many college students know these are just the right tools for playing a drinking game called “beer pong.” The only thing missing is the beer. The rules for beer pong, much like Monopoly, vary from place to place, according to bpong.com, organizers of the Beer Pong World Series and self-styled “center of the beer pong universe.” But the overall goal is to bounce a ping-pong ball into a plastic cup. If you miss, you drink.