Most players online at one time in an FPS war game

In the online first-person shooter (FPS) PlanetSide, players take the role of a soldier fighting for one of three factions seeking domination of the planet Auraxis. On 23 March 2003, a record 6,400 players logged on to the Emerald server for a mega-battle for control of the planet. Guinness World Records Gamers' Edition 2009.