Taken from UKRDA
“Roller derby is a full-contact women’s sport played on quad roller skates, by players skating around an elliptical track. The game consists of a series of two-minute countdown jams.
At the start of each jam, each team sends five players onto the track: one jammer (point scorer), threeblockers (defensive/offensive players) and one pivot (last line of defence and lead blocker). The players are identified by their helmet covers – a stripe for the pivots and two stars for the jammers. The pivots and blockers form a pack at the start line and the two jammers line up 20 feet behind the pack. The pack starts rolling on the referee’s first whistle, and the jammers sprint on the second whistle. The jammers’ aim is to make it through the pack of skaters and skate a full lap to enter the pack again. Once they re-enter the pack, they score a point for each opposing skater they pass legally.
Now for the fun bit: the skaters in the pack are doing their utmost to stop the opposing jammer passing them and scoring points, while at the same time trying to help their own jammer to pass opposing players. They do this by landing heavy shoulder or hip checks on opposing players, shoving them out of the way or knocking them to the ground. Any part of the front of a skater’s body between shoulder and mid-thigh is a target zone, and any part of the body between shoulder and mid-thigh (excluding hands, elbows, and forearms) is legal to hit with. Illegal hits result in time served in the penalty box, legal hits often result in skaters flying off the track and landing in the crowd!
The game is fast and furious and full of adrenaline – once you see it you’ll be hooked.”