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 who survived the outbreak make their way through the city of Fairfield, only to discover that the virus is creating new, even more dangerous mutations. After narrowly avoiding these new Infected, along with Hordes of others, the Survivors are alerted to the presence of an evacuation point at the nearby Mercy Hospital by a passing news helicopter. Fighting their way through the city's streets, subway and sewers, the Survivors are rescued from the hospital's roof by the pilot, only to discover that he is succumbing to the Infection.

With the youngest of the group forced to kill the pilot, the helicopter crash lands 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.

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.

Afterwards, instead of being taken to the Echo Safe Zone, the Survivors are taken to a military base at Millhaven with orders to capture and test "Tango Mikes" as the military refers to them. They are informed that they are Carriers of the virus, and, while showing no physical symptoms, they can still infect others. An alarm is sounded by a rebellious lieutenant and the Survivors are guided to a train by helpful military staff. Their newfound friends are unfortunately left for dead as the eldest Survivor refuses to compromise his fellow Survivors by letting them board.

The train then stops in 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 where they believe there are to be no Infected. Their journey brings them to a sailboat blocked off by a lift bridge. The Survivors work to get the bridge lifted so they can wait for the Horde to go away then get down and hijack the boat; however, the generators lifting the bridge stop halfway to the top. The oldest of the Survivors then decides to risk his life to save the other Survivors and get them out safely. He jumps off the bridge and makes his way back to the generator and restarts it, but before he can make his way back, he is attacked by three Tanks and mortally wounded.

To make sure his sacrifice wasn't in vain, the three remaining Survivors set sail for the Florida Keys, but only after helping four other Survivors which they help out by lowering the bridge to let them on their way to New Orleans.

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.