PC download service Steam has introduced support for free to play (F2P) games, with five new titles being added to the service from today.
The first games to become available are Sega's Spiral Knights, Perfect World's Forsaken Worlds, Atari's Champions Online: Free for All (Atari), Hi-Rez Studios' Global Agenda: Free Agent, and NHN USA's Alliance of Valiant Arms (AVA).
Steam will promote a new "F2P game of the day" all week, with in-game microtransactions handled by the Steamworks backend system already used in titles such as Valve's own Team Fortress 2.
"The introduction of free to play games is another example of the constant evolution of Steam," said Jason Holtman, director of business development at Valve.
"Free to play games offer new game genres and game experiences for customers, while offering developers and publishers new revenue opportunities and the ability to reach customers in areas of the world where the traditional packaged goods model is less popular than F2P."