Left 4 Dead

First off, you can now play the two campaigns Death Toll and Dead Air online in Versus mode. These maps have been tweaked slightly to remove some closets and to balance gameplay. For example, downstairs in the Boathouse Finale has been significantly emptied to prevent corner camping, and more walls break open. The anticipated Survival Mode is released, which pits The Survivors against endless waves of the horde, as well as multiple Special Infected. Players can hold out in 16 maps, 15 of which are extracts from Crescendo Events and finales from the four original campaigns. These maps have also been tweaked to remove exploits and to make the whole experience much harder. The last map is in the new campaign: The Last Stand, and currently has one map: The Lighthouse.

The Sacrifice" is the prequel to "The Passing," and takes place from the Left 4D Survivors' perspective as they make their way South. We know Bill dies in "The Passing" but how and why? You can read the comic to find out the official version of events or this October 5th you can play the game to choose your own ending. In The Sacrifice for Left 4 Dead, gamers receive the complete Sacrifice campaign with maps playable in Campaign, Versus, and Survival. There is a new style finale and plenty of places for devastating Hunter pounces. For Left 4 Dead 2, gamers receive "The Sacrifice" campaign and L4D1's "No Mercy" both playable with the L4D1 Survivors. Each campaign is playable in Campaign, Versus, Survival, and Scavenge modes and both feature the Left 4 Dead 2 Special Infected, items, and weapons. Yes, Zoey with a chainsaw!

Crash Course is the first DLC campaign for Left 4 Dead. According to Valve it is meant to bridge the gap between No Mercy and Death Toll. Crash Course is the shortest of any Left 4 Dead campaign and contains only two chapters. Crash Course begins shortly after the events of No Mercy. The helicopter rescue pilot from the Rooftop Finale succumbs to the Infection and Zoey shoots him in mid-flight. The helicopter crashes in an industrial area outside of the city of Fairfield in Whitney County. Starting from next to the helicopter crash site, the Survivors traverse Fairfield's industrial landscape. Initially there is no firm clue about their destination until they make reference to a truck depot and discuss the town of Riverside where a military evacuation center is reported to be. This plan obviously foreshadows and contextualizes the Death Toll campaign. At the truck depot they discover an armored truck mounted on a workshop hoist which must be lowered before they can board and escape. Activating a generator for this purpose triggers a finale horde attack. In another act of foreshadowing, the generator stalls partway through the battle and one survivor must run out and restart it: the same problem occurs in The Sacrifice except the survivor who volunteers is certain to die.

"The Last Stand" is a "campaign" exclusive to Survival Mode. It was introduced in Survival Pack—the first DLC for Left 4 Dead.