From the rules:
'Roller Derby takes on all the excitement of the real sport. Each manager has a team forming a "Pack". This team has four players and one "Jammer".
All players on a team wear the same colour.
The game board contains a unique mechanism that causes the skaters to move side to side in a realistic way. Once the board has started to rotate, the action becomes hectic, with each player trying to get his "Jammer" through the "Pack".
The "Jammer" is a single man with a magnet in the colored base. This man is controlled by a "Jammer Stick" of the same color. The "Jammer Stick" is held under the skating surface and engages the same color "Jammer" above. By skilfully using the "Jammer Stick", that player can be guided through the moving "Pack". The "Jammer Stick" will not control the opponent's color "Jammer".'
Object is to be the first to guide the "Jammer" through the "Pack" to score the most points.
1. 25 points or more in one game
2. A match of five games (each consisting of 25 points).