Roller derby is an American team sport, which involves formation roller skating on an oval track, wherein players are expected to lap their opponents to score points. What started off as a form of sports entertainment, has now become a professional sport, predominantly involving women, and at times, men. The popularity of this sport can be attributed to fact that it is based on athleticism and aggression, and its rules play an important role in ensuring that the right blend of athleticism and aggression prevails. Roller Derby Rules and Regulations The number of roller derby leagues around the world has increased significantly over the last two decades. The rules adopted by most of these leagues are the ones that have been constituted by the Women's Flat Track Derby Association (WFTDA) based in the United States. Duration: Each roller derby game is played for a duration of one hour. This may include 2 periods of 30 minutes each, or 3 periods of 20 minutes each. After each jam, the players can re-form the pack and continue to play. Players and Formation: Attack and defense are carried on at the same time in roller derby, wherein each team consists of 5 players (i.e., 3 blockers, 1 pivot, and 1 jammer) during the play. In the beginning, the pivots and blockers from both teams come together to form a 'pack'. The pivots lead the pack, followed by 4 blockers, 2 from each team, who are in turn followed by 2 blockers, 1 from each team. The jammers are positioned at 20 feet behind the pack at this point of time. Start: The first whistle from the referee is meant to start the jam formation, wherein the blockers and pivots need to stay in the pack, complete one circuit, and pass the spot from where the pivots started. Once formed, the pack has to be maintained throughout the jam. Once the pack formation is complete, the referee blows the whistle twice, which is the signal for the jammers to start. Jam: The jam is a 2-minute period, wherein the pack and the jammers circuit the track in a counter-clockwise direction. The jammers need to lap the pack as many times as possible to score the points. After they lap the entire pack once, the scoring starts, and every time the jammer laps a player from the opposition, she scores a point for her team. All this while, the blockers and pivots are expected to be in a pack. If they fall or get separated from the pack, they can't block the jammers until they rejoin it. Lead Jammer: The first jammer to lap all the blockers and pivots becomes the lead jammer and thus, gains the power to cease the jam at any point of time before the scheduled 2-minute period. She just has to put her hands on her lap repeatedly to signal the referee to stop the jam officially. The jammers have the option of passing their positions to the pivots of their team, but if the lead jammer does this, the team has to forfeit the lead jammer position for rest of the jam. Blocking: The pack can block the opposition team players in order to stop their scoring. For this, the blockers can use the upper portion of the body, above the mid thigh, excluding hands or head. Elbows should not be used for blocking, hitting, or holding the jammer in any case. These actions are considered illegal and call for a penalty. Penalties: There also exists a series of penalties enlisted among the various rules and regulations. Blocking illegally, engaging in a fight, or unsporting behavior can lead to the player being penalized according to the rules of roller derby. The penalty may include being sent to the penalty box or being forced out of the game. A player faces the penalty threat after one major penalty or four minor penalties. Even Leo Seltzer, who invented the roller derby way back in 1930s, wouldn't have had thought that his creation would gain so much popularity throughout the world some day. Moving out of the American continent, today this extreme sport has spread its fame in several European and Australian countries, like Australia, New Zealand, Belgium, Germany, Ireland, Netherlands, and the United Kingdom. While some people like it for the athleticism involved, others like it for the sheer fact that you get to witness a colorful extravaganza on the track circuit.