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Can I activate Stacking on Steam if I buy it from GoG? I'd like to have all my games in one place.

You're only buying a DRM-free version here on GOG.
But you could easily include the game to your library by adding it as a Non-Steam game.
Yes I added it on my good external HD.
I spit on GOG if GOG give Steam key.
Post edited January 29, 2013 by ERISS