You will see a lot of checkered purple and black objects, and actual 'ERROR' messages like this: A complete list of Source games can be found here.īy not having the correct games, you could potentially be missing the textures needed to play maps created by others.

I would say at the minimum, you will need that game (and you might as well get Team Fortress 2 since it's free). and many more! But the majority of the textures are handled with just Counter Strike: Source. It's important to note that some others games that may be needed are basically any game that run on the Source Engine developed by Valve. Team Fortress 2 has been free since June 23, 2011. This Reddit also provides some more details.Ĭounter Strike: Source is currently $19.99 at posting. Please note: Some multiplayer servers and game-modes might require you to own other games - such as Counter-Strike: Source and Team Fortress 2. However, you will need to purchase and download (possibly) Counter Strike: Source and Team Fortress 2 for a lot of the textures and other game objects.

Technically - you do not need to purchase anymore games.