Left 4 Dead

Left 4 Dead (abbreviated L4D) is a singleplayer and multiplayer cooperative survival horror FPS game developed by Valve Corporation and Turtle Rock Studios. The game was built using Source engine and is available on PC and Xbox 360. During early development, its working title was "Terror Strike."

The game puts four human playable or AI-controlled Survivors of an apocalyptic pandemic against Hordes of the Infected. Regular Infected are controlled by the game AI, while human players can control up to four mutated Special Infected with special abilities in Versus mode. The goal of Left 4 Dead for the Survivors is to help each other make it through a level to safety. Infected players must cooperate to stop them.

The basic gameplay never changes from map to map, so players will learn their way around fairly quickly. The Director keeps things from getting monotonous, however, by throwing in different challenges in every level. No two playthroughs are exactly alike.

Plot
Left 4 Dead begins in Pennsylvania, following an outbreak of the so-called Green Flu, a highly contagious virus whose symptoms include significantly increased aggression and the loss of many higher brain functions within its victim.

Two weeks after the start of the epidemic, four immune individuals; Bill, Zoey, Francis and Louis are in Fairfield, where Bill discovers the remains of an unusual Infected, signifying that they are evolving. Bill and Zoey soon hear crying and head to investigate the source, while Francis and Louis stand guard. Bill and Zoey discover a new Infected, which is immediately startled by Louis when he flashes his light at her, but they are able to kill her in time before she breaks the door down. They manage to take down the incoming horde, which also included three new Infected strains just as a helicopter passed over the roof of the building they were in, informing any Survivors to make their way to Mercy Hospital for evacuation.

The group fought their way through Fairfield and reached the hospital, which was overrun with Infected. Despite the opposition, they managed to reach the rooftop and contacted the pilot, who immediately made his way to the hospital rooftop and evacuated them as a Horde was attacking them.

Unfortunately, the pilot soon became infected, forcing Zoey to shoot him, causing the helicopter to crash in an industrial district outside the city. Finding a delivery truck that has been armored by other Survivors, the group decides to use it to make their way to the town of Riverside.

Before arriving in the town, however, they find the road blocked, and are forced to travel the rest of the way on foot. Following an encounter with an Infected madman in the local church, they discover that the town is overrun, and decide to head to a nearby boathouse for possible rescue. Contacting a small fishing vessel owned by a married couple, they are thrown off board in the city of Newburg on the other side of the river, only to find much of it in flames.

Seeking cover in a large greenhouse, their rest is interrupted when a military plane passes overhead, leading the Survivors to travel through the city's business district towards Metro International Airport. Upon arrival, the group is shocked to see that in an attempt to contain the Infection, the military had bombed the airport. The runway, however, is largely intact, allowing the Survivors to fuel up and escape in the waiting C-130, its pilot too scared to leave the plane to refuel.

Despite this apparent rescue, the Survivors once again find themselves alone on the outskirts of Allegheny National Forest. Following a series of train tracks through the area, the group find themselves at a functioning but abandoned military outpost. After answering a radio transmission, the Survivors make a stand in a farmhouse against hordes of Infected, before a military APC arrives to transport them to Northeast Safe Zone, supposedly the only location in the area yet to be overrun.

Instead of being taken to the Echo Safe Zone however, the Survivors are taken to a military base at Millhaven with orders to capture and test "Tango Mikes" as the military refers to them. Bill and Zoey are taken away for examination, while Louis and Francis are quarantined into a padded cell. Millhaven's commanding officer, Major Everly, refuses to believe Lt. Mora's report's of the Special Infected, prompting the lieutenant to stage a rebellion in secret. Bill and Zoey encounter a doctor, who informs them that they are Carriers, people immune to the infection, but are capable of spreading it to others. Meanwhile, Louis and Francis are guarded by two soldiers, with Francis attempting to goad one inside to fight but failing, while the other decides to ask Louis what is going on outside. The two soldiers introduce themselves as Jeff and Annie, and learn how dangerous the Special Infected are.

Lt. Mora completes his rebellion and sets off the alarm, unaware that the Infected are attracted to sound, which causes a massive horde to bear down on the facility and overwhelm the unprepared soldiers. After a Wandering Witch passes through the hallway where Jeff and Annie are guarding Louis and Francis, the two decide to release them due to their knowledge on the Special Infected, and lead them into an armory to resupply. Bill also had the same idea, and find the four inside the armory. They learn from Jeff and Annie that there is a train depot on the other side leading out of the base, and the Survivors decide to use it as their means of getting out. They arrive at a depot after killing a Tank, where Jeff and Annie voluntarily leave the group, unwilling to become infected as they themselves do not know if they are Carriers or not, opting to fight the horde at a choke point despite being informed it is certain death. The doctor remains with the group, but he struggles to catch up with the train just as a smaller horde arrives to attack, and is left for dead as Bill refuses to compromise the group's safety for someone they barely knew, much to Zoey's anger.

The tracks stop at Rayford, Georgia, a city located not too far away from Atlanta. Their disputes put aside for now, the group begins looking for a sailboat to take them to the Florida Keys, as Bill believes that the Infection will not be able to reach the islands. While searching for a suitable transportation Louis is wounded by multiple Witches and has the yacht burnt down. They soon come upon another yacht filled with supplies and decide to take it with them to the Florida Keys, but soon find out that they need to raise the bridge to get the yacht across. They find several generators to power the bridge, just as a massive horde with four Tanks appear as the bridge malfunctions halfway. Bill heads down to restart the generator, and believes that he will be able to make it back, before a Tank surprises and mortally wounds him. Zoey, Francis and Louis soon realize Bill hasn't returned and realize he had died protecting them as the bridge finally raises high enough to prevent most of the Infected from reaching them.

A week later, the three encounter another group of Survivors who escaped Liberty Mall and are seeking passage across the river with their car. Either Zoey or Francis informs them they must go across the river to restart the generator, and the group manages to make it across. The new group asks the three if they would like to join them on their trip to New Orleans as the military is still active there, but the three kindly refuse, having been sick of the military. The new Survivors refuel the generator and resume their trip to New Orleans. After finalizing their preparations, Zoey, Francis and Louis take their yacht and set sail to the Florida Keys.

The Survivors
There are four playable human characters in the game. Every Survivor has their own unique appearance, personality, and background, though all Survivors are equal in speed, strength, rate of fire and health, etc. There is no "strongest" Survivor, so character choice is purely player preference.

The Infected
The Infected are the main antagonists of Left 4 Dead. The Survivors encounter the Common Infected the most, which are normal humans Infected by the Green Flu, which makes them attack the Survivors as soon as they see them.

In addition to the Common Infected, there are five different types of Special Infected in the game. Only four are usable by players in Versus Mode. Each Infected has its own unique attacks and method of use, but all attempt to work in tandem to defeat the Survivors before they complete the level.

Levels
Each of the 5 (6 if you include The Sacrifice) campaigns has the player(s) follow a generic path of going from point A to point B with a few different routes and awards stating who took the least damage, etc.

Split screen
Split screen play is officially supported on the Xbox 360 version of the game; allowing players to play both online and offline with a friend. Split screen play on PC is unsupported but still possible, as the core features are built into the game but no GUI exists to acess them. Using an Xbox 360 controller for PC, and some console commands, one can load maps in splitscreen mode and play offline with a friend. To play on any server, offline or online, in splitscreen mode, use the console command: ss_connect. Splitscreen requires more draw calls and thus a higher-end processor is recommended.

Development
Development of the game started in mid-2005 and was revealed revealed in the Christmas 2006 publication of PC Gamer UK with a six-page article describing a playthrough at Valve's headquarters. A teaser was released with The Orange Box.

The game was first playable at the Showdown 2007 LAN in San Jose and at QuakeCon 2007. A demo, initially to be released on November 6, 2008 to people who pre-ordered the game, was publicly released on November 11, 2008.

The Cover


Valve says the cover represents the title of the game, due to the hand being the "left" hand while only having "4" fingers while also being "dead," making up the title (Left 4 Dead).

Also, others have speculated that the hand has some sort of significance to what transpired during the first two weeks, as another image of this hand being x-rayed can be seen in The Hospital level in No Mercy and is in the very first scene of the intro cutscene.

A thumb was added in the German and Japanese version for censorship reasons.

The hand on the cover is also the hand seen in the beginning of the trailer.



Release
Left 4 Dead was released on November 18, 2008 in the United States, and November 21st in Europe and Japan to coincide with the 10th anniversary of Half-Life's release.

Post-Release and Reception
As of January 24, 2010, Left 4 Dead has an 89 out of 100 from Metacritic. Regarding information about the updates for Left 4 Dead, see Updates.

The 200th issue of Game Informer Magazine ranked Left 4 Dead as #82 in the top 200 games of all time. This is what they had to say: "Zombies have appeared in video games in many forms, but nobody ever nailed the full-on zombie apocalypse until Valve's Left 4 Dead. The intense four-player online co-op experience utilized a dynamic 'AI Director' to adjust the undead onslaught according to player performance. Toss in memorable characters, an intriguingly sparse plot, and an online versus mode, and you had the penultimate test of mettle for any zombie-crusader worth their salt."

DLC
Several months after release, Valve announced plans to support the game through free content packs.
 * The Survival Pack
 * Crash Course Campaign
 * The Sacrifice Campaign

Engine
See: Source (game engine)

Left 4 Dead uses the latest version of Valve's Source engine, with improvements such as multi-core processor support and physics-based animation to more realistically portray hair and clothing.

Many kinds of post processing cinematic visual effects have been added to the game, each intended to elicit responses from players and guide them through the game. These include situational color correction, contrast and sharpening, film grain and vignetting.

Dry surfaces and fog are used to create mood.

Other games that use the Source Engine include:
 * Counter-Strike: Source
 * Garry's Mod
 * The Orange Box (Team Fortress 2, Portal and Half-Life 2, Half-Life 2: Episode One and Half-Life 2: Episode Two)
 * Half-Life: Source is a straight port of the original Half-Life game to the Source engine.
 * Vindictus
 * Postal III
 * Vampire: The Masquerade - Bloodlines
 * Zeno Clash
 * Sin Episodes Emergence
 * Dark Messiah of Might and Magic
 * Portal 2
 * Left 4 Dead 2
 * Day of Defeat: Source
 * Alien Swarm

Controls
These are the default controls of Left 4 Dead for both the PC and Xbox 360 versions.

Context sensitive controls

 * The X button is used to interact with other things. Using it, you can pick up objects, open doors, or help other Survivors to their feet or give your first aid kit to other Survivors.
 * Select the first aid kit, target a teammate and press and hold LT to heal them. It has the same effect as them healing themselves. (It will therefore take 5 seconds and heal damage depending on the current hp of the person)
 * Select the pain pills, target a teammate, press and hold LT to give the pills to them.

Refer to health for further tips. Make sure your teammates know how to revive you and give first aid kits and/or pain pills to you. The Survivors need to watch out for each other.