The suggested setup is similar to your typical game of muggle beer pong, except for the addition of the three Quidditch rings placed between the two sets of cups as well as a separate "Snitch Cup" placed farther away, "at a distance that is difficult, but not impossible to make," according to the rules. Two teams of three people -- one person designated as the team's Seeker -- take turns making shots either through the hoops or around them. Successful shots through the hoop score you a bonus cup. Among other Harry Potter-inspired plays like spells, a team can exchange its three shots for one attempt by the Seeker to make the "Snitch Cup," which would end the game.
Unfortunately, the Quidditch Beer Pong set is currently sold out on the site, so if you really want to prove yourself as a champion, you'll have join the waiting list. But in the meantime, you can try to make your own set (just don't ask Seamus Finnigan for help), or you can always hit up the Room of Requirement. No matter what, Quidditch Pong responsibly.