The sequel to the critically acclaimed Left 4 Dead, Left 4 Dead 2 takes play in the deep South of the USA. Set in a modern day survival-horror universe, the co-operative gameplay of L4D casts four Survivors in an epic struggle against hordes of swarming zombies and terrifying Boss Infected mutants. Left 4 Dead 2 adds melee combat to enable deeper co-operative gameplay, with items such as a chainsaw, frying pan, axe, baseball bat, and more.

Introducing the AI Director 2.0, L4D's dynamic gameplay is taken to the next level by giving the Director the ability to procedurally change weather effects, world objects, and pathways in addition to tailoring the enemy population, effects, and sounds to match the players' performance. The result is a unique game session custom fitted to provide a satisfying and uniquely challenging experience each time the game is played.