Collusion detection and control

A system for detecting and controlling collusion in a multiplayer game having a plurality of participating players in which the players compete against each other to determine a winner, the system comprising:

• recording means for recording, for each player, an amount wagered on each turn of the game in which the player participates, and a corresponding outcome of said wager, the outcome being a complete or partial forfeit of the wager if the wager is unsuccessful, and a profit made on the wager if the wager is successful;
• a ranking facility operable to derive a primary statistic for each player, the primary statistic being a function of a total number of turns of the game played by the player, and the outcomes of the wagers made by the player in these turns of the game;
• and
• monitoring means for monitoring the primary statistic of each player and generating an output when the primary statistic of any player changes by more than a predetermined amount, the output being an indicator of possible collusion by that player.