Roller Derby

Two teams of 5 skaters battle it out for position over a series of "jams" which last up to 2 minutes. Four "blockers" on each team and one "jammer". The jammer's job is to score points. After her initial pass through the "pack" of blockers, a jammer will score one point each time she passes a member of the opposing team. The blockers attempt to assist their own jammer while hindering the opposing jammer — playing both offense and defence simultaneously.

The game ends after the period clock runs out, and the team with the most points wins.