Valve has announced that Steam will be letting free-to-play titles on the service, which will be supported by micro-transactions. The first titles will be Spiral Knights, Forsaken Worlds, Champions Online: Free for All, Global Agenda: Free Agent, and Alliance of Valliant Arms.

“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.”