Roller Derby is a full-contact, competitive sport conducted on four-wheeled skates. It can be played on an oval, flat track outlined on a smooth, flat surface (like the Arizona Derby Dames have done for four full seasons) or on an oval banked track, approximately 60' x 100' (which is what the Derby Dames have competed on since 2010). The skaters skate in a counter-clockwise direction. Each team consists of a maximum of 18 players. Each game is called a bout. Arizona Derby Dames bouts in 2010 consist of four 12-minute long periods that are subdivided into 60-second jams. Jams consist of five players from each team. These five players fill a pivot position, three blocker positions, and one jammer position. The grouping of pivots and blockers from both teams skating together is called the pack.
Pivots: are the skaters in the front of pack wearing the striped helmets. They set the pace for the pack and are the last line of defense to prevent the opposing jammer from scoring. Blockers cannot skate more than twenty feet in front of the pivot.
Blockers: line up behind the pivot and in front of the jammer. They play offense and defense. It is their job to prevent the opposing jammer from scoring, while assisting their jammer successfully through the pack.
Jammers: are the point scorers and are positioned at the back of the pack. They are the only ones that score points and are identified by the helmet with a star. It is their role to make their way through the pack. Whoever makes their way through the pack first without committing a penalty is designated the lead jammer.
The Jam: starts when the referee blows the whistle and the pack takes off. On the second whistle blow, the jammers take off and begin to work their way through the pack. Once the jammers break through the pack the first time, whichever jammer is ahead at any given time during the jam becomes the lead jammer. The jammers lap the pack and when they re-enter, they score one point for each opposing member they pass. A jam lasts a maximum of 60 seconds, but the lead jammer can call off the jam by placing her hands on her hips anytime at her discretion.
Penalties: Yes, despite the combativeness on wheels, there are penalties. These include:
Illegal Blocking: swinging elbows, blocking from behind, blocking out of bounds, blocking 20' away from the pack, intentionally falling in front of another skater, grabbing, touching or holding with forearms; pushing. Penalties will earn the offender time in the penalty box and that skater's team will skate short one skater for the duration of that penalty.