Aikouka
Lifer
- Nov 27, 2001
- 30,383
- 912
- 126
I think I'm going to definitely have to get MW2, Borderlands, and Magicka then...
You should never assume that a game can simply be added to Steam as it's not always the case. If a game requires Steam (whether it's considered Steamworks or not), then it can be added regardless of where you buy it from. Magicka is an example of this, but I'm pretty certain that Borderlands is not. I've only ever purchased it on Steam though, so I can't be certain without looking it up.
There is actually a list that Valve has which states which game keys can be redeemed on Steam.