What happens if you already have copies of the bonus games? (GMG is pushing the same thing).

I already pre-ordered on Amazon, and I think I'll stick there. It comes with the Codebreaker mission, so there's that, and I already have all the X-Com games. I'm tempted by Spec Ops, but not enough to change my order.

You'll probably get giftable copies.

STeam i understand, but anyone know what happens on GMG? My understanding is GMG will only allow one copy of a game on an account, and if you already have a copy of a game.....

Good question, unless you get separate keys since it's a preorder item. You're better off asking them directly.