The Guinness Book of World Records has recognised RuneScape as the world's largest free massively multiplayer online role-playing game.
In addition to being the world's largest free MMO, the game is also the second largest MMO in the world, according to developer Jagex, with over one million paying subscribers and five million players taking advantage of the free game.
"We are delighted to be recognised as the biggest free MMO in the world," commented Geoff Iddison, CEO of Jagex.
"This is great recognition for RuneScape and following the launch of RuneScape HD in July, RuneScape is going from strength to strength".
The company claims the title has been played by over 138 million people globally since launch in 2001.