Roller Derby is a full contact sport played on quad skates.
A game lasts an hour and is broken down into jams, each of which can last up to 2 minutes.
There are 2 teams of up to 14 skaters, during a jam each team will field 4 Blockers and 2 Jammers.
The Jammers score points by passing legally through the Blockers. The Blockers have to try and stop the opposing Jammer from scoring points whilst at the same time trying to help their own Jammer through.
See below for an easy to follow Roller Derby breakdown.