This weekend, Call of Duty: Black Ops 2 multiplayer can be played for free on Steam until Sunday 1pm PST. Buying the game within those hours will decrease the original price by 33% for both the standard and digital deluxe edition (which includes bonus maps Nuketown 2025 and Nuketown Zombies, the Black Ops 2 official soundtrack, free COD: World at War and several in-game items). Double XP is also happening simultaneously for Xbox 360, PS3, PC and Wii U up until Monday. The clock has already started ticking, so what are you waiting for? Your friends are ready to fight zombies with you all through the weekends!