Blizzard Entertainment has announced that its MMORPG World of Warcraft, is now being played by more than 11.5 million subscribers worldwide.
This new high was reached following the release of the game's second expansion, Wrath of the Lich King on 13 November.
Within its first 24 hours of availability, Wrath of the Lich King sold more than 2.8 million copies, and more than 4 million in the first month, making it the fastest-selling PC game of all time.
Both sales records were previously held by World of Warcraft's first expansion, The Burning Crusade.
"We're pleased to welcome the new and returning players who have helped World of Warcraft reach these new milestones, and we appreciate the enthusiasm and support that the game's global community has continued to show", said Mike Morhaime, CEO and co-founder of Blizzard Entertainment.
"We look forward to providing all of them with an excellent entertainment experience for a long time to come".
Bob McKenzie, senior vice president of merchandising at GameStop, added: "Not only is Wrath of the Lich King still doing well, the base World of Warcraft game and the World of Warcraft Battle Chest are performing better than last year.
"That type of traction is very impressive for a game that is going into its fifth holiday season and speaks to the enthusiastic player base Blizzard Entertainment products have".