If I'll buy the game from G2A, I think I'll only get the serial number, and not the actual game. So, where can I download the game after that? G2A seams a lot cheaper than Steam.

1 Answer

Open your steam client, and go to the library tab. At the bottom left corner of the client there should be an "Add Games" link. Clicking that opens up a prompt that walks you through adding the game.

2