Roller Derby is a full contact sport played on roller skates on an oval track. It is played in two 30 minute period split into 'jams' running to a maximum of 2 minutes. Two teams field five players at a time and aim to get their jammer out of the pack to score points.
Each team will consist of up to 14 players, with a maximum of 5 players fielded for each 'jam'. These 5 players usually consist of; 4 blockers and 1 jammer.
The blockers, including 1 pivot blocker, make up the pack and are simulataneoudly focused on helping their own jammer (offence) and blocking the opposing jammer (defence).
The jammers (identified by the star cover they wear on their helmet) race to pass through the pack, complete their initial pass and gain lead jammer status. The Lead jammer has the right to call the jam off early to gain a tactical advantage, such as stopping the other team from scoring. On subsequent passes, the jammer will receive a point for each opponent they pass legally. Scoring passes are a maximum of 5 points per pass (including lapping the other jammer).
This continues until either the lead jammer calls the jam or the jam reaches the full 2 minutes.
Any skater that receives a penalty must report to the penalty box for 30 seconds. Penalties are issued for a number of reasons, such as hitting an illegal area of the oppositions body.
Most importantly, the team with the most points at the end wins!