Forget all these DayZ blow-ins. Before there were zombies, BI's ArmA II was a game known for its brutal adherence to military strategy, an uncompromising sandbox in which people could get close—but not too close—to actual combat conditions.

Nothing shows this more elegantly than ShackTac's 2012 Year in Review video, which compiles the year's best footage from the group's exploits in the game. If you need to know what's special, know that every person you see is being controlled by a human player, and that a single bullet can, and often will, kill.

ShackTac 2012 Year in Review [YouTube, via PC Gamer]