Roller Derby is a contact sport played by two teams of five members roller skating counter-clockwise around a track.
Game play consists of a series of short match-ups (jams) in which both teams designate a jammer (who wears a star on the helmet). The jammer scores points by lapping members of the opposing team. The teams attempt to hinder the opposing jammer while assisting their own jammer—in effect, playing both offense and defense simultaneously.
Contemporary roller derby has a basic set of rules, with variations reflecting the interests of a governing body's member leagues. The summary below is based on the rules of the Women's Flat Track Derby Association (WFTDA).In March 2010, Derby News Network claimed that more than 98% of roller derby competitions were conducted under WFTDA rules.
Roller derby is played in two periods of 30 minutes. Two teams of up to 15 players each field up to five members for episodes called "jams." Jams last two minutes unless called off prematurely. Each team designates a scoring player (the "jammer"); the other four members are "blockers." One blocker can be designated as a "pivot"—a blocker who is allowed to become a jammer in the course of play. The next jam may involve different players of the 15 roster players, and different selections for jammer and pivot.
During each jam, players skate counterclockwise on a circuit track. Points are scored only by a team's jammer. After breaking through the pack and skating one lap to begin another "trip" through the pack, the jammer scores one point for passing any opposing blocker. The rules describe an "earned" pass; notably, the jammer must be in-bounds and upright. The jammer's first earned pass scores a point for passing that blocker and a point for each opponent blocker not on the track (for instance, serving a penalty, or when the opposition did not field five players for the jam). If the jammer passes the entire pack, it is a four-point scoring trip, commonly called a "grand slam."
Each team's blockers use body contact, changing positions, and other tactics to help their jammer score while hindering the opposing team's jammer.
Play begins by blockers lining up on the track anywhere between the "jammer line" and the "pivot line" 30 feet in front. The jammers start behind the jammer line. Jams begin on a single short whistle blast, upon which both jammers and blockers may begin engaging immediately.
The pack is the largest single group of blockers containing members of both teams skating in proximity, arranged such that each player is within 10 feet of the next. Blockers must maintain the pack, but can skate freely within 20 feet behind and ahead of it, an area known as the "engagement zone."
The first jammer to break through the pack earns the status of "lead jammer." A designated referee blows the whistle twice, and skates near, and points at, the lead jammer. Once earned, lead jammer status cannot be transferred to other skaters, but certain actions (notably, being sent to the penalty box) can cause it to be lost. The lead jammer can stop the jam at any time by repeatedly placing both hands on their hips. If the jam is not stopped early, it ends after two minutes. If time remains in the period, teams then have 30 seconds to get on the track and line up for the next jam. If the period expires, it does not halt a jam that is underway.
A skater may block an opponent to impede their movement or to force them out of bounds. The blocker must be upright, skating counterclockwise, in bounds, and within the engagement zone. Blocking with hands, elbows, head, and feet is prohibited, as is contact above the shoulders or below mid-thigh, and blocking from behind.
Referees penalize rules violations. A player receiving a penalty is removed from play to sit in a penalty box for 30 seconds of jam time. If the jam ends during this interval, the player remains in the penalty box during the subsequent jam until the interval ends. The penalized player's team plays short-handed, as in ice hockey.
However, the "power jam", derived from hockey's "power play", does not cover any short-handed situation but only the case where the jammer is penalized. In this case, that team cannot score. While the lead jammer is penalized, no one can prematurely end the jam.
It would be pointless to play if neither team could score; thus, a jammer is released from the penalty box early if the opponents' jammer enters the box. The second jammer's penalty is then only as long as the amount of time the first jammer spent in the box. A player "fouls out" of the game on the seventh penalty, and is required to return to the locker room.
Players skate on four-wheeled ("quad") roller skates, and are required to wear protective equipment, including a helmet, wrist guards, elbow pads, knee pads, and mouth guards. All current sets of roller derby rules explicitly forbid inline skates for players. (USARS requires quad skates for all skaters. WFTDA and MRDA permit inline skates for referees, but virtually all referees wear quad skates.) Individual teams may mandate additional gear, such as padded knee length pants, similar to what aggressive skateboarders wear, and biologically specific gear such as a hard-case sports bra for female players and protective cups for males.
Strats and Tacts
Offense and defense are played simultaneously, a volatile aspect that complicates strategy and tactics. For example, blockers may create a large hole for their jammer to pass through and score, but this same maneuver might also allow the opposing team's jammer to score.
Ending the JAM: The lead jammer can "call off" or end the jam at any time, controlling the opposition's ability to score points. The strategy for a jam is not to score a lot of points but to outscore the opposition. Often, the lead jammer scores as many points as possible on the first scoring trip, and then ends the jam before the opposing jammer can begin a scoring trip. If the jammer gets the lead but falls behind the opposing jammer, the coach may conclude that the team will be outscored and direct the jammer to call off the jam.
Passing the STAR: The jammer for a team may "pass the star" (may perform a "star pass") to the pivot—that is, hand the helmet cover with the star to the pivot, which turns the pivot into the jammer. Passing the star does not nullify any earned pass of an opponent that the former jammer made, but passing the star forward never constitutes an earned pass. A jammer might pass the star because of fatigue, injury, or because the pivot is in a better position to score. Passing the star is also sometimes referred to as "passing the panty", as helmet covers are sometimes known as "panties".
Penalty-KILLING: Captained by the pivot, blockers adapt their play to a penalty situation. For example, a short-handed team may try to make the pack skate faster to slow down scoring action until the team returns to full strength.
Walling Up: Two or more blockers skate together to make it difficult for the opposing team (especially its jammer) to maneuver. They may skate side-by-side and use a "wide stance" to maximize the blockade, but must not link with or grasp each other, or otherwise form an impenetrable connection. The ability to suddenly form a wall denies the opposition time to respond. A wall can inhibit, slow down, and ultimately trap the opposing jammer. An effective wall may last for an entire jam. Variations on the tactic include the following:
Backwards bracing, in which one skater, forward of the wall, skates backward to sight the jammer and direct teammates forming the wall.
A skater may break off from the wall to actively challenge the opposing jammer, with a teammate replacing the skater in the wall.
If the opposing jammer tries to pass the wall on one side, players may abandon the other side to fortify the active side of the wall.
Jammer Tactics, in response to a wall or other obstacles by the defense, include the following:
Pushing through gaps in the wall or inducing the wall to separate by use of physical force.
Evading the obstacle to one side or the other.
Juking, where the jammer seems to be skating to one side but quickly shifts to the other side.
Rolling around the end of the obstacle (spinning 360°) to end up forward of it.
Using teammates to impede the defense from adjusting, such as by setting screens.
Using a whip, where one or more teammates grasp the jammer's hand(s) and swing the jammer forward, transferring speed and momentum to the jammer.
Using the inside curve of the track to leap out of bounds but land in bounds.
Goating: The pack is defined as the largest group of in-bounds blockers, skating in proximity, containing members from both teams. In the "goat-herding" tactic, one team surrounds a blocker of the opposing team, and then slows so that that group becomes the pack. The rest of the opposing team, skating ahead, are thus put out of play and cannot legally block the goat-herders' jammer.
Running Back or Recycling: When a skater bumps the opponent jammer off the track, the jammer can only re-enter the track behind the skater. The skater skates clockwise on the track toward the rear of the engagement zone to maximize the time the jammer must spend before returning to action.
Bridging: By separating up to 10 feet, blockers can stretch both the pack and the engagement zone, allowing teammates to keep hindering the opposition jammer. For example, in the strategy of running back (see above), coordinated action by the four skaters other than the jammer could force the opponent jammer to detour a full 40 feet before returning to action.