It looks like Valve is going to be having more sales from their library of games on Steam more often than just the weekend from now on. We've already told you about their $5 sale for S.T.A.L.K.E.R.: Shadow of Chernobyl. Today they have another pretty large sale for The Witcher, the fantasy RPG from developer CD Projekt.

From now until Thursday, you can purchase and download The Witcher for $19.99 via Steam, which is a 50 percent reduction from its usual price. The sale is apparently to celebrate the fact that the game is now available via Steam worldwide instead of just the US. And if you haven't tried out the game this might be a good time to do so as CD Projekt seems to be knee deep in production for the sequel, The Witcher 2.

Update: Impulse has the same sale price for The Witcher.