Valve’s digital portal, Steam, has said it will open the in-game micropayments model for external studio partners.
The Washington-based company has begun the new microtransaction push by hosting five free-to-play games on its storefront.
The likes of Cryptic's Champion's Online and Hi Rez Studios' Global Agenda are the first of a new batch of free-to-play games available on the digital store. More are expected to follow.
It is not known how much Valve takes from a single microtransaction payment, though industry averages on digital royalties usually provides around 70 per cent of total revenues to the developer.