What is Roller Derby?
Roller Derby is a full contact sport played on roller skates on an oval track. Five members each from two opposing teams face off in shifts called "jams". One member from each team acts as the "jammer", all other players on the track are "blockers". The jammers try to pass the blockers on the opposing team to score points. Two thirty minute periods are played in each game. The team who has the most points at the end, wins.
For more information, visit the WFTDA's page.