Vegas 12

Vegas 12 was an entertainment world, presumably based on and named after the town of Las Vegas on Earth and colonised by humans.

A popular form of entertainment on this world was 'Live Chess'named for the electrified chess pieces used in the game. Such matches were played in giant spectated 'Chess Pits'. The Doctor faced Gantok in a game of Live Chess in exchange for information regarding The Silence.

(DW: The Wedding of River Song)