Campaigns

Campaigns (or movies) are story lines consisting of several chapters (levels, maps). At the end of each chapter, players are given awards for how well they did on certain aspects. If at least one Survivor escapes after the finale, credits will roll with the Survivors' final results. Much like the awards, the credits are completely cosmetic.

Each campaign features a "finale", in which the Survivors call for help and must face a gigantic horde while waiting for rescue to arrive. This includes several waves of Common Infected and Special Infected, as well as two or more Tanks (though, never a Witch). After holding off the Infected for a certain period of time, the remaining Survivors (if any) head to the rescue vehicle.

Left 4 Dead
Currently, Left 4 Dead has five campaigns playable in Campaign and Versus, with the sixth only available in Survival and more confirmed to come from Downloadable Content. They are, in chronological order:
 * 1) No Mercy, focused on moving towards a Hospital for evacuation. Takes place in an apartment building, subway station, sewer, Mercy Hospital, and a Rooftop Finale. The rescue vehicle that saves the Survivors is a News 5 Helicopter.
 * 2) Crash Course takes place directly after the No Mercy Rescue. The News 5 Helicopter crashes in an area close to The Turnpike in Death Toll. The helicopter is caused to crash after Zoey kills the pilot who is, in fact, infected. This campaign is focused on delivering a full multi-player campaign in just 1/2 hour. It was released for download on the 29th of September 2009.
 * 3) Death Toll takes place from an abandoned highway, the drainage system of Riverside, a church, the town of Riverside and the Boathouse Finale. In which the Survivors contact two civilians; John and Amanda Slater. A boat arrives to rescue the Survivors.
 * 4) Dead Air, a campaign focused on getting through an Infected greenhouse, through a metropolitan area, an air station terminal, and finally, a last stand at a Runway Finale. Dead Air's rescue vehicle is a C-130 Hercules that has run out of fuel, and the Survivors must wait for it to fuel before they are rescued.
 * 5) Blood Harvest, a campaign that revolves around getting to a military base in a rural area. This campaign begins with a wooded area, continues on to a train yard, and culminates in a Farmhouse Finale reminiscent of the film Night of the Living Dead. An M93 Fox Armored Personnel Carrier is the rescue vehicle in Blood Harvest's campaign.
 * 6) The Last Stand, this campaign has only one level, The Lighthouse. This campaign can only be played after downloading the Survival DLC. It is located in the woods, with a large lake off to the side, unreachable by the Survivors. As it can only be played in Survival Mode, there is no rescue vehicle that arrives to rescue the Survivors and always ends with the Survivors' death.
 * 7) Unnamed Campaign-  This campaign has been announced by Valve in an Interview on the Xbox 360. It will explain how the Survivors reached The Passing.

Storyline
There is no definitive storyline involving the six campaigns (with the exception of No Mercy, Crash Course, and Death Toll) in Left 4 Dead, only a collection of maps where you need to get from Point A to point B. It is unknown if Valve will ever pick up a solid story after the initial cutscene. However, the campaigns can be linked to one another with careful observations, but this does not define it as Left 4 Dead canon.

However, it is worth noting that according to the Developer Commentary, the game was originally supposed to be one large campaign, but was later split up. For example, No Mercy and Death Toll were directly linked; in the former's Rooftop Finale, the helicopter pilot reveals that he tried to do a ground pickup, but was bitten by the Infected in the process. Unfortunately, he soon dies, and the helicopter crash-lands on The Turnpike where the Death Toll campaign begins. Though most of the sound clips have been removed from the game, their audio files are still in the game files. They can be heard here. However, it is now known that the helicopter crashes in The Alleys from the Crash Course campaign, which links No Mercy and Death Toll. Death Toll links also to Dead Air as the start of The Greenhouse shows if a player uses no-clip to go through the back wall of the safe house, the rescue boat from The Boathouse Finale of Death Toll can be seen moored up on the riverside quay, however, the boat is different from the one that rescues the Survivors in Death Toll.

Left 4 Dead 2
Left 4 Dead 2 currently has five campaigns playable in all gameplay modes.

The game's campaigns are listed below, in chronological order:


 * 1) Dead Center - In Savannah, GA, four complete strangers find themselves caught up in the chaos of a recent outbreak of the deadly Infection currently sweeping across the United States. Banding together to stay alive, the Survivors have to shoot their way down through a burning hotel and through the Infected-swarmed city streets to a nearby shopping mall, where they hope to use a famous race car being exhibited there to make their escape.
 * 2) The Passing - Not much is known about this campaign at the moment other than it set after Dead Center campaign, and it involves the Left 4 Dead Survivors meeting up with the Left 4 Dead 2 Survivors. It is also set in a rural Georgia town.
 * 3) Dark Carnival - Upon finding the freeway out of Savannah blocked by abandoned cars, the Survivors are forced to leave their vehicle and make their way on foot to the nearby Whispering Oaks amusement park, still partially operational and crawling with Infected. As a patrolling rescue helicopter circles overhead, the Survivors must make their way down the park's midway, through the Tunnel of Love, over the tracks of a roller coaster, and past the exhibition barns to reach the park's stadium, where the pyrotechnics display of a rock concert stage may provide them with their only means of signaling the chopper pilot for help.
 * 4) Swamp Fever - Unfortunately for the Survivors, the helicopter pilot that rescued them from Whispering Oaks succumbs to the Infection, and they are forced to kill him and crash-land the chopper in the Mississippi bayou. Finding evidence that rescue may be waiting deeper in the swamp, the Survivors must trek through an abandoned alligator farm, an airliner crash site, and a ramshackle shantytown where the local swampfolk made their last stand against the Infected. Eventually, they reach a giant plantation house, where they must hold off the relentless hordes of Infected until a kindly skipper named Virgil arrives with a rescue boat to take them to a rumored safe zone in New Orleans, LA.
 * 5) Hard Rain - As the evening sun begins to set, the Survivors learn that their rescue boat doesn't have enough fuel to reach New Orleans. Virgil drops them off in the derelict town of Ducatel, MS, to look for more. Their situation is further complicated by forgetting to bring signal flares to indicate that they've retrieved the fuel, as well as the sudden onset of a torrential downpour, the first sign of an incoming hurricane. The Survivors must move through suburban streets teeming with Infected and a half-demolished sugar mill to reach a gas station. After obtaining the fuel, they must then make their way back through the mill and the town, both now flooded by the storm, to return to the dock, signal Virgil with the illuminated sign from a nearby Burger Tank, and escape before the full force of the storm hits.
 * 6) The Parish - Virgil, who rescued the Survivors in Hard Rain and Swamp Fever, leaves them in New Orleans as he goes in search of more Survivors. The Survivors find the city completely overrun by the Infected. They have to make their way through the streets of the French Quarter, the military's abandoned quarantine zone, and an above-ground cemetery until they finally arrive at a partially collapsed table bridge. On the other side is a military helicopter waiting to take the Survivors out of the city to a flotilla of commandeered cruise ships in the Gulf of Mexico, where the last remnants of humanity in the area have regrouped, safe in the knowledge that the Infected can't swim...so far...

Storyline
The Survivors begin their trek on the top of a hotel, watching their suppose-to-be rescue helicopter fly away, leaving them stranded in Savannah, Georgia. They make their way down to ground level, where they then decide to head to a local mall said to be an evacuation station for CEDA. Along the way, they aid a middle-aged man by delivering bottles of soda in exchange for fire-arms and a clear path to the evacuation station. Once at the mall, they discover it overrun with Infected and the health stations destroyed. With no where else to go, they fuel up a racing stock car put up for a show and make their escape, driving until their progress is barred by numerous abandoned vehicles on the highway.

The sun has set and the car is now immobile, the Survivors are forced to travel on foot over the stopped cars. In the distance they see search lights, so they make their way towards them praying there will be someone around who can help. They discover the source of the lights to be a carnival which they traverse, finding nothing but Survivor-hating Infected. Overhead, a helicopter can be heard, so they follow it till they reach a stadium, where they use lighting equipment and loud rock and roll music to inform the pilot of their presence. The plan works, and the Survivors are rescued by the generous pilot. At least it seemed that way until he began turning pale and attempted an attack.

In self defense, and perhaps protecting of his comrades, Nick kills the now Infected pilot, sending the helicopter crashing near some boxcars and a shantytown located in the heart of the Mississippi swamps. The survivors go through an abandoned swamp city, go across a river in a mechanical ferry, head through zombie infested swamps and bayou and reach the swamp town. Unfortunately, the Survivors find out that the town did not last and was overrun by the Infection. Through the advice of previous Survivors' graffiti, the quartet make their way to a Plantation house, where they are able to contact a boat captain to come and pick them up. They make it out alive, and continue down the Mississippi River, on their way to New Orleans, Louisiana.

Unfortunately, their ship is running low on fuel, and is incapable of reaching New Orleans. The Survivors are dropped off on the coast of a small suburban town named Ducatel with the task to find fuel for the boat engine. Unfortunately, the gas station across the street is out of diesel and a sign tells them that the next available gas is two miles away on the other side of a witch infested sugar mill. Along the way, the clouds start to roll in and rain starts to fall a little. Once they've gotten the gas needed to fuel their ship, a downpour starts up, and the roads begin to flood, forcing the Survivors to find other paths amongst the higher ground to make it back to the docks. Left without a method of signaling the success of their mission, they use the lights of a fast food restaurant, named Burger Tank, to alert their vessel instead. Their plan works, and they are able to make it safely back onto the boat with enough fuel to reach their destination.

After a nights rest on their floating vessel, the Survivors reach New Orleans mid-day and set off to a supposed military evacuation set up on Veteran's Memorial Bridge. After traveling through the city that the Infected took over, they soon become victims of their own saviors as the military begins dropping bombs in the city. After ducking and dodging bombs, they reach the bridge where they are able to contact soldiers via a radio clutched in the hand of a dead man. They are provided clearance to cross the bridge to the evacuation vehicle on the other side of the bay. They finally find themselves flying away from their troubles, and making it out to safety as the bridge they were just on is bombed, and collapses into the bay.

Awards
Once each level in a campaign is completed, players are presented with several awards. These awards are purely cosmetic and do not affect gameplay. Only the most relevant will be shown.

Note: The following are only given in Versus Mode.
 * General Defense - Killed the most Infected.
 * Tank Slayer - Did the most damage to the Tank.
 * Least Damage Taken - Took the least amount of damage.
 * Protector - Protected the most teammates.
 * Witch Hunter - Did the most damage to the Witch.
 * Headhunter - Got the most headshots.
 * Special Killer - Killed the most Special Infected. This is only shown if there were no Tanks or Witches in the chapter.
 * Most Careful Teammate - Lowest friendly fire incidents.
 * Total Damage - Did the most damage to the Survivors.
 * Boomer Damage - Did the most damage as a Boomer.
 * Hunter Damage - Did the most damage as a Hunter.
 * Smoker Damage - Did the most damage as a Smoker.
 * Hunter Pounces - Pounced the most Survivors.
 * Tank Punches - Punched the most Survivors.
 * Most Vomit - Vomited on the most Survivors.
 * Survivor Drags - Dragged the most Survivors.

Credits
If at least one Survivor makes it out of the campaign alive, credits will roll. If all of the Survivors escape, text stating "The Survivors have escaped!" will appear. However, if any of the Survivors do not make it to the escape vehicle, this text will be replaced with: "In memory of:". This will then be followed by the names of the deceased Survivors. Following either of those scenarios, the credits will continue with information such as: As a humorous reference to normal movie credits, the total amount of Infected killed is mentioned at the end as "X zombies were harmed in the making of this film."
 * Who took the least damage
 * Who used the most molotovs/pipes/pills/etc
 * How many of each Special Infected everyone killed
 * The number of Common Infected killed
 * The Survivors' accuracy by percentage of shots that hit Infected.
 * Headshot percentage.