For battlefield to battlefield, there is always a multiplayer part which needs a CD KEY code, for this time it's Battlefield 3 made by DICE and EA. Using the most futuristic sound system and great graphics, like frostbite 2.0. Steam doesn't have BF3 this year, but it's Origin now and we are liking it cause of the new interface. For cracking a game you will need a working one, and after u will need to write in a serial key.
A longer read, about this shooter for PC, Battlefield 3 will feature the maximalist combined arms battles that made the series popular across single-player, co-operative and multiplayer modes as such rush and others from BC2. It will reintroduce several elements absent from the Bad Company games, including fighter jets, the prone position and 64-player battles on PC. Check out Batman Arkham City serial key also
Serial keys To accommodate the lower player count on consoles, the ground area will be limited for Xbox 360 and PS3, though fly space will remain the same