A game with two teams and two Frisbees. Each team consists of two players and is located in a field of 13x13 meters. The distance between both fields is 17 meters. Dropping the disc and throwing it out of bounds of the opponent's field is punished. The team who forces the other team to have both Frisbees at the same time, scores a so called "Double" which is two points.
The official rules can be found here: http://www.wfdf.org/art2.htm