Half-Life 2



Half-Life 2 (HL2) is a first-person shooter computer game and the sequel to Half-Life, developed by the Valve Software Corporation. It was released on November 16 2004 following a protracted five-year development cycle during which the game's source code was leaked to the Internet. The game garnered near unanimous positive reviews and received critical acclaim, winning over 35 Game of the Year awards for 2005.

Taking place in and around the fictional City 17 sometime in the near future, Half-Life 2 follows the scientist Gordon Freeman. Gordon Freeman is thrust into an unfamiliar environment in which the aftermath of the Black Mesa Incident come to bear fully upon human society. Freeman is forced to battle against increasingly unfavorable odds in order to free Mankind from the Combine. In his struggle, he is joined by various allies, including fellow scientists, soldiers, and friends (like Alyx Vance).

The game uses the Source Engine, which includes a heavily modified version of the Havok physics engine. Half-Life 2 has been critically acclaimed for advances in computer animation, sound, narration, computer graphics, artificial intelligence (AI) and physics. When sales figures were last announced, over four million copies of Half-Life 2 had been sold. Roughly 25 percent of all Half-Life 2 copies have been purchased using the Steam content delivery service; their exact number is between 750,000 and one million, depending on whether they are included in the figure of four million. Overall, the Half-Life franchise, including Counter-Strike and Day of Defeat, has seen over 15 million sales.

To date, an Xbox port of the game has also been released. Half-Life 2 is included in the Orange Box for Playstation 3, Xbox 360 and PC.

Prologue
The original Half-Life, released on November 19, 1998, largely took place at a remote civilian and military laboratory called the Black Mesa Research Facility. During an experiment, researchers at Black Mesa accidentally caused a "resonance cascade" which ripped open a portal to an alien world, Xen. Creatures from Xen flooded into Black Mesa via the portal and began attacking the facility's personnel on sight. The player took on the role of Gordon Freeman, one of the research scientists involved in the accident, guiding him in his attempt to escape the facility. At the end of the game, Gordon was extracted by a mysterious figure colloquially known as the G-Man who offered him a "choice": employment or a fight he could not possibly win. Upon accepting the job offer, Gordon was put into stasis by the G-Man.

Half-Life canon dictates that Gordon Freeman either agreed or was not given a real option with respect to the G-Man's offer. Half-Life 2 picks up the story with the G-Man taking Freeman out of stasis and inserting him on a train en-route to City 17 an indeterminate number of years after the Black Mesa Incident. Official sources differ on the actual length of this intermission—a story fragment written by author Marc Laidlaw for the development team puts the intermission at 10 years, while Half-Life 2: Episode One's Web site puts this intermission as "nearly two decades" after the end of the events of Half-Life.

Storyline
At the start of the game, the G-Man speaks to Gordon Freeman as part of a hallucination-like vision as he is pulled out of stasis and placed on a train. Gordon exits the train to find that the world has been overtaken by an extradimensional military force known as the Combine. Gordon meets up with Barney Calhoun and sets out for Doctor Isaac Kleiner's lab while being chased by Combine Civil Protection, meeting Alyx Vance along the way. Once they've reached their destination, Kleiner attempts to teleport them to Black Mesa East: though Alyx arrives successfully, Kleiner's pet headcrab, Lamarr, damages the device as Gordon is about to teleport, causing a malfunction. Gordon is briefly teleported to several seemingly random locations, most notably Dr. Breen's office (twice), who recognises him and alerts the Combine to his reappearance. He finally materializes just outside the window of Kleiner's lab. Barney instructs Gordon to take the city's canals to get to Black Mesa East, where Alyx's father, Dr. Eli Vance, works.

While navigating through the city's canals, Gordon is chased by the Combine on foot until being supplied with an Airboat at a rebel outpost; by this point it becomes increasingly obvious that Gordon has a heroic, almost messianic reputation with the rebels and outlaws. However, the Airboat is soon spotted by the Combine and pursued by a hunter-chopper assault helicopter. Using a salvaged hunter-chopper turret, Gordon manages to take down the pursuing helicopter. He arrives at Black Mesa East and meets Eli Vance and Judith Mossman, also rejoining Alyx. Alyx gives him a tool originally developed for handling hazardous or heavy materials called the Zero-Point Energy Field Manipulator (also known as the Gravity Gun) and instructs Gordon on its use while also introducing Dog, her giant "pet" robot. Shortly thereafter, the lab is attacked by the Combine, forcing Gordon to escape through an old tunnel leading to the nearby town of Ravenholm.

Gordon enters Ravenholm, an old mining town and former rebel outpost, and soon discovers why it has been abandoned. After discovering the town harbored Resistance members, the Combine bombarded it with headcrab shells, causing the town to become almost completely overrun with headcrabs and zombies. The resulting carnage left most of the town's inhabitants dead. The town's only known survivor, Father Grigori, helps Gordon through Ravenholm and ultimately shows him to the mines on the outskirts of the town, which lead to some nearby dockyards. Freeman is alerted by Alyx via radio that Eli has been captured and is being held in Nova Prospekt. Gordon embarks on a journey to Nova Prospekt in a Dune buggy, helping to down a Combine gunship after meeting Colonel Odessa Cubbage at a small Resistance outpost named New Little Odessa; Cubbage gives him an RPG launcher for this purpose. The journey is made difficult due to Antlion infestation along the coast, but once Gordon kills their Antlion Guard master, the Vortigaunts are able to extract pheropods which Gordon can then use to control a number of antlions in the assault on Nova Prospekt.

At Nova Prospekt, Gordon searches for Eli. Alyx joins with Gordon again, and together they find both Eli and Doctor Judith Mossman (revealed to be a Combine spy). Mossman creates a distraction and teleports herself and Eli into the Citadel, while Gordon and Alyx teleport themselves to Doctor Kleiner's lab. A malfunction in the equipment causes a huge explosion, which causes the time to slow down during the teleportation, contracting seven days into a few seconds. They arrive at Doctor Kleiner's lab a week after they left Nova Prospekt. During this lost week, the destruction of Nova Prospekt has been taken as a signal to begin the uprising, turning City 17 into a warzone. Gordon joins up with leads freedom fighters towards the Citadel to free Doctor Vance while Alyx helps Doctor Kleiner escape the lab. Later, Alyx briefly rejoins and accompanies Gordon in a battle to disable a Combine power generator, but is subsequently captured by Combine forces. After reaching Barney, Gordon shuts down a suppression device blocking access to the Citadel and brings down a pack of Striders.

Gordon enters the Citadel through an underground passage. All of his weapons are destroyed by a "confiscation field", except for the gravity gun. An unexpected reaction with the confiscation field causes the gun's powers to be amplified, and using this Gordon wreaks havoc upon the Citadel. Gordon enters a containment apparatus, which brings him face-to-face with Doctor Breen. Doctor Judith Mossman is with Breen, and he summons Eli and Alyx, who are being held in similar devices. During the confrontation, Breen remarks that Freeman's services are "open to the highest bidder." As Breen threatens the Vances, Judith turns against him. Breen manages to escape to a "Dark Energy Reactor" at the top of the Citadel with the intent of teleporting himself away from Earth. Gordon and Alyx pursue him, and Gordon destroys the reactor, both to depower the Citadel and to prevent Breen's escape. This triggers a massive explosion in which Alyx and Gordon are imperiled. However, at the moment the reactor explodes, time stops. The G-Man emerges, commenting on Gordon's successful endeavors. He places Gordon back into stasis and leaves through a door of pure light. The game ends exactly as it began, in darkness. The story continues from this point in Half-Life 2: Episode One.

Narrative
Throughout the entire game, Gordon never speaks, the action is viewed through his eyes only (i.e., there are no cut scenes), and there are no discontinuities or jumps in time (from his point of view).

There has been some criticism of these narrative holdovers from Half-Life, since they effectively limit how much of the backstory is explained. Due to the lack of cut scenes, the player never directly sees what has happened in Gordon's absence. Ultimately, it is not clear to what extent Gordon exists as a separate character outside of the player's influence. Since the start of Half-Life, Valve has made sure that the player's and Gordon's experience are one and the same. An example of Valve's player strategy is shown during the scene in Eli's lab. Investigation of certain props (most notably the newspaper board) triggers Eli to give some explanation to their meaning and history, thus indicating that Gordon presents emotions that the NPCs can detect.

The ending of Half-Life 2 is also very similar to that of the original: after completing a difficult task against seemingly overwhelming odds, Gordon is extracted by the G-Man. Gordon is smugly congratulated and told that further assignments should follow. The fates of many of the major characters, such as Alyx, Eli, and Judith, go unexplained. Very few of the questions raised by Half-Life are answered, and several new ones are presented. The identity and nature of the G-Man remains a mystery. A number of these issues are addressed, however, in the sequel games, Episode One and Episode Two.

Setting
The environments in Half-Life 2 are varied, ranging from the generally Eastern European-styled City 17 and the zombie-infested town of Ravenholm, to the coastal Nova Prospekt prison and the massive Combine Citadel. Viktor Antonov, the art director of Half-Life 2, being a Bulgarian, spent his childhood in Bulgaria, wrote that Eastern Europe was favored as a setting for the game as it is capable of depicting a combination of both new and old architecture, creating a city with history; "gothic themes associated with Prague and vampires" were also overlooked in favor of a different aspect of the region.

The game's setting sees frequent appearances of Cyrillic letters on signs and graffiti (written in Bulgarian spelling); this has led some to argue that City 17 is in fact a Combine-altered Sofia, Bulgaria. Old cars scattered throughout the game are Soviet-made and used to be commonly found in Eastern Europe, such as Moskvitchs, Zaporozhets, Volgas (GAZ-24), Latvias (RAF-2203), and ZIL-130s BDM-2s. During the game, Gordon comes to a coastal Resistance settlement called New Little Odessa; Little Odessa is the nickname for the Russian community in Brighton Beach, where many ex-Soviet immigrants settled (the original Odessa is a major city located on the coast of Ukraine). Father Grigori has a name common in Slavic Eastern European countries, an accent that is stereotypically Slavic Eastern European, and has been identified as a clergyman of the Orthodox Christian Church, the predominant religious institution found in many (though not all) Slavic Eastern European countries.Besides this there are also at one point on the "Highway 17"level,you go to a gas station named Northern petrol where the info on the gas pumps are written in swedish

Half-Life 2 differs from many other FPS by incorporating elements of survival horror, most notably in the Ravenholm level. The anguished atmosphere of this is akin to the likes of Silent Hill, combined with a large and intricate level design.

Chapters

 * Chapter 1: Point Insertion
 * Chapter 2: "A Red Letter Day"
 * Chapter 3: Route Kanal
 * Chapter 4: Water Hazard
 * Chapter 5: Black Mesa East
 * Chapter 6: "We Don't Go To Ravenholm"
 * Chapter 7: Highway 17
 * Chapter 8: Sandtraps
 * Chapter 9: Nova Prospekt
 * Chapter 9a: Entanglement
 * Chapter 10: Anticitizen One
 * Chapter 11: "Follow Freeman!"
 * Chapter 12: Our Benefactors
 * Chapter 13: Dark Energy
 * Chapter 14: Credits

Gameplay
Half-Life 2's gameplay is broadly similar to that of the original. Players make their way through a linear series of levels, encountering both humanoid troops and hostile alien creatures. As in Half-Life, the gameplay is broken up with a series of puzzles; however, Half-Life 2 includes physics-based puzzles. For example, one puzzle requires the player to either turn a seesaw-like lever into a ramp by placing cinder blocks at one end, or to stack the cinder blocks into a crude stairway.

The use of physics extends into combat with the gravity gun. This unique weapon plays a crucial function throughout the game, granting the player an unprecedented amount of creativity in its use, such as picking up and throwing objects at enemies, holding objects indefinitely for use as makeshift cover, grabbing health and ammunition from out of reach places, returning enemies' grenades, building makeshift bridges, or manipulating objects through Combine forcefields.

Vehicles are another major gameplay addition. The player has the ability to drive two vehicles during the single player campaign; an air boat, which Gordon uses to navigate through the canal network, and a dune buggy which Gordon uses to get to Nova Prospekt. The air boat is initially unarmed, but is later mounted with a Combine weapon from a downed hunter-chopper. The buggy is armed with a Tau Cannon that functions exactly like the one found in the original Half-Life.

The game also integrates tutorial-like tasks in the storyline itself and includes on-screen instructions on game controls (but no longer includes separate tutorial levels featured in the original) to allow familiarization of the game's mechanics and weapons for players as they go. Several such examples include an early incident in game where a Civil Protection unit orders the player to "pick up" a tin can and "throw it" into the trash can, and Alyx Vance's introduction of the gravity gun at Black Mesa East, or even instructions on how to use Antlion Pheropods by a Vortigaunt.

Characters and creatures
Although Gordon battles through much of Half-Life 2 alone, he is at times assisted by friendly allies. For the most part these are human members of the resistance, but Gordon is also helped by Vortigaunts and later Antlions. This latter insectoid species is new to the Half-Life universe and is encountered first as a fiercely territorial foe, but is later co-opted into acting as an abundant and obedient ally. At several key locations, Gordon also meets up with, and fights alongside, more significant non-player characters like Alyx Vance, Barney Calhoun and Alyx's robot, Dog.

Many familiar enemies from Half-Life return in this game, such as headcrabs, barnacles, and headcrab zombies. However, the majority of the game is spent fighting the Combine, who wield large military forces against Gordon and the people of City 17. Combine forces are varied and consist of modified humans, biomechanical machines, and robotic weapons, including the use of headcrabs as biological weapons.

Weapons
Several of the weapons featured in Half-Life 2 are carried over from Half-Life, including the trademark crowbar for mêlée fighting, and many conventional firearms such as a pump-action shotgun. and a .357 Magnum revolver, as well as more unorthodox weapons like a crossbow that fires highly heated rebar sections, and a laser-guided RPG launcher as well as the Tau Cannon, an experimental particle weapon that is mounted on the Dune buggy. Several new weapons are also introduced: a submachine gun with attached grenade launcher (based on the H&K MP7 Personal Defence Weapon), a 9mm Pistol (based on the H&K USP Match), the AR2 Combine Overwatch pulse rifle; 'pheropods' which grant control over Antlions, and most significantly, the Zero-Point Energy Field Manipulator, or gravity gun.

Multiplayer
Half-Life 2 was released without an in-universe multiplayer component, and was instead packaged with Counter-Strike: Source. This later changed on November 30, 2004 when Valve released the Half-Life 2: Deathmatch component along with the full SDK as a free download to all Half-Life 2 owners. The Xbox release contains no multiplayer component.

Like other deathmatch games, the aim of Half-Life 2: Deathmatch is to kill as many other players as possible, using a variety of means, in either free-for-all or team matches. The player spawns with a Gravity Gun, a 9mm Pistol, a sub-machine gun, and grenades. All weapons included in the single player portion of Half-Life 2, with the exception of the pheropods, are available and scattered randomly around the maps. Players can be killed in a number of ways, including gunfire, explosions, or through contact with physics objects traveling at high speeds.

Half-Life 2: Deathmatch ' s February 17 update introduced a new map (dm_steamlab) and three new weapons that had been missing from the game previously, or cut before it shipped. This included the crowbar and the stunstick (dependent upon the player model); and the SLAM, or "Selectable Lightweight Attack Munition", a real-world weapon which can either be thrown and detonated or planted on walls to produce a "tripwire" laser which detonates the device when in contact with an object or person.

Reception
Half-Life 2's public reception was overwhelmingly positive in terms of reviews, acclaim and sales. Over four million copies of the game have been sold either through Steam or through retail. This is around half the number of sold copies of Half-Life, but sales for Half-Life 2 have been relatively steady since its release. If Half-Life 2 eventually surpasses Half-Life in sales, it will take the title of the best-selling first-person shooter game to date.

Critical response
Half-Life 2 became and remains one of the most highly acclaimed video games in history. At least 35 Game of the Year awards were given to Half-Life 2, and most major game reviewers gave ratings within the 90-100% range. Half-Life 2 holds Metacritic's highest ranking and standing ("universal acclaim") among PC games with a score of 96, followed directly by Half-Life (also with a score of 96). Maximum PC awarded Half-Life 2 an unprecedented 11 on their rating scale which peaks at 10, and named it the "best game ever made."

Individual reviews were almost universally glowing. Sources such as GameSpy, The Cincinnati Enquirer, and The New York Times have given perfect reviewing scores, and others such as PC Gamer and IGN gave near-perfect scores (it was one of only four games ever to get 96% from UK PC Gamer, the best score they have ever awarded, and the game is only one of two games ever to get a near perfect score, 98%, from PC Gamer), while the game became the fifth title to receive Edge magazine's ten-out-of-ten score. Critics who applauded the game cited the advanced graphics and physics along with the relatively lax system requirements.

Very few reviewers gave Half-Life 2 lower than a nine out of ten rating. One such critic was Netjak, a reviewing website known for its relative harshness, which gave Half-Life 2 a rating of 8.5. Several critics, including some that had given glowing reviews, complained about the required usage of Steam along with a difficult installation process.

Awards
Half-Life 2 earned over 35 Game of the Year awards, including Overall Game of the Year at IGN, GameSpot's Award for Best Shooter, Gamespot's Reader's Choice - PC Game of the Year Award, Game of the Year from The Academy of Interactive Arts & Sciences, and "Best Game" with the Game Developers Choice Awards, where it was also given various awards for technology, characters, and writing. The game also had a strong showing at the 2004 BAFTA Games Awards, picking up 6 awards, more than any other game that night, with awards including "Best Game" and "Best Online Game."

Products
The popularity of Half-Life 2 and the Half-Life series has led way to an array of side products and collectibles. Valve offers Half-Life-related products such as a plush headcrab, posters, clothing and mousepads.

Allies
All Allies excluding the Gman will attack Headcrabs/Zombies, Barnacles, Antlions (excluding allied antlions) and Combine.
 * Gman
 * Samuel
 * Citizens
 * Vortigaunt
 * Barney Calhoun
 * Isaac Kleiner
 * Alyx Vance
 * Hedy Lamarr
 * Joe
 * Matt
 * Resistance Fighters
 * All-Knowing Vortigaunt
 * Judith Mossman
 * Eli Vance
 * Dog
 * Father Grigori
 * Leon
 * Noriko
 * Odessa Cubbage
 * Laszlo
 * Sandy
 * Antlion (Only at the last Part of Sandtraps and during Nova Prospekt).

Xenian: Headcrab
Headcrabs/Zombies will attack Barnacles, Antlions, Combine and all Allies.
 * Headcrab
 * Zombie
 * Fast Headcrab
 * Fast Zombie
 * Poison Headcrab
 * Poison Zombie

Xenian: Barnacle
Barnacles will attack Headcrabs/Zombies, Antlions, Combine and all Allies.
 * Barnacle

Xenian: Antlion
Antlions will attack Headcrabs/Zombies, Barnacles, Combine and all Allies.
 * Antlion
 * Antlion Guard

Xenian: Ichthyosaur
Ichthyosaur will attack Gordon.
 * Ichthyosaur

Combine
Combine will attack Headcrabs/Zombies, Barnacles, Antlions and all Allies
 * Civil Protection
 * Overwatch Soldier
 * Nova Prospekt Prison Guard
 * Overwatch Sniper
 * Overwatch Elite
 * Stalker
 * City Scanner
 * Manhack
 * Hunter-Chopper
 * APC
 * Shield Scanner
 * Combine Dropship
 * Combine gunship
 * Mortar Synth
 * Strider
 * Crab Synth

Source engine
For Half-Life 2, Valve Corporation developed a new game engine called the Source engine, which handles the game's visual, audio, and artificial intelligence elements. The Source engine comes packaged with a heavily modified version of the Havok physics engine that allows for an extra dimension of interactivity in both single player and online environments.

Additionally, when coupled with Steam, the engine can be easily upgraded to include many new graphical technologies. One such example is high dynamic range lighting, which Valve Corporation debuted as a free level called Half-Life 2: Lost Coast, which functions as a playable tech demo for the new technology.

Steam content delivery system
Integral to Half-Life 2 is the Steam content delivery system developed by Valve Corporation. All Half-Life 2 players are required to have Steam installed and a valid account in order to play. Steam allows customers to purchase games and other software straight from the developer and have it downloaded directly to their computer as well as receiving "micro updates." These updates also make hacking the game harder to do and has thus far been somewhat successful in staving off cheats and playability for users with unauthorized copies. Steam can also be used for finding and playing multi-player games through an integrated server browser and friends list, and game data can be backed up with a standard CD or DVD burner. Steam and a customer's purchased content can be downloaded onto any computer, as long as that account is only logged in at one location at a time.

The usage of Steam has not gone without controversy. Some users have reported numerous problems with Steam, sometimes being serious enough to prevent a reviewer from recommending a given title available on the service. In other cases, review scores have been lowered. Long download times, seemingly unnecessary updates, and verification checks are criticisms leveled by critics of the system's use for single player games such as Half-Life 2. Whether or not a customer intends to use any multi-player features, the computer the game was installed on must have Steam and an Internet connection to verify the transaction.

Release and distribution
A 1GB portion of Half-Life 2 became available for pre-load through Steam on August 26, 2004. This meant that customers could begin to download encrypted game files to their computer before the game was released. When the game's release date arrived, customers were able to pay for the game through Steam, unlock the files on their hard drives and play the game immediately, without having to wait for the whole game to download. The pre-load period lasted for several weeks, with several subsequent portions of the game being made available, to ensure all customers had a chance to download the content before the game was released.

Half-Life 2 was simultaneously released through Steam, CD (most initial U.S. "bare-bones" retail copies), and on DVD in several editions. Through Steam, Half-Life 2 had three packages that a customer could order. The basic version ("Bronze") includes only Half-Life 2 and Counter-Strike: Source, whereas the "Silver" and "Gold" (collector's edition) versions also include Half-Life: Source and Day of Defeat: Source (ports of the original Half-Life and Day of Defeat mod to the new engine) as well as the right to download all previous games by Valve through Steam. The collector's edition/Gold version additionally includes merchandise such as a t-shirt, a strategy guide, and a CD containing the soundtrack used in Half-Life 2. Both the disc and Steam version require Steam to be installed and active for play.

Subsequent releases
A demo version with the file size of a single-CD was later made available in December 2004 at the web site of graphics card manufacturer ATI Technologies, who teamed up with Valve for the game. The demo contains part of the opening level of the game, and also part of the chapter "We Don't Go To Ravenholm." In September 2005, Electronic Arts distributed the Game of the Year edition of Half-Life 2. Compared to the original CD-release of Half-Life 2, the GOTY edition adds Half-Life: Source.

On December 22, 2005, Valve released a 64-bit version of the Source game engine that takes advantage of AMD64 processor based systems running 64-bit version of Windows operating system. This update, delivered via Steam, enabled Half-Life 2 and other Source-based games to run natively on AMD64 processors, bypassing the 32-bit emulator. Gabe Newell, one of the founders of Valve, stated that this is "an important step in the evolution of our game content and tools," and that the game benefits greatly from the update. The response to the release varied: some users reported huge performance boosts, while technology site Techgage found several stability issues and no notable frame rate improvement. 64-bit users have widely reported bizarre in-game errors including characters dropping dead, game script files not being pre-cached (i.e., loaded when first requested instead), map rules being bent by AI, and other glitches.

Ports
An Xbox port published by Electronic Arts was released on November 15, 2005. While subject to positive reception, critics cited its lack of multiplayer game|multiplayer and frame-rate issues as problems, and the game received much lower scores than its PC counterpart.

During Electronic Arts's summer press event on July 13, 2006, Gabe Newell announced that Half-Life 2 will ship on next-generation consoles (specifically, the PlayStation 3 and Xbox 360) including episodes One and Two, Team Fortress 2, and Portal. This 5 game package would later be known as "The Orange Box" and was shipped to PC and Xbox 360 on October 10, 2007. The Playstation 3 version was delayed and finally shipped December 11, 2007. There were reports Valve was having troubles with the Playstation 3 hardware and it shows with bouts of slowdown that are not seen on the Xbox 360 or PC versions.

Mods and expansions


Since the release of Half-Life 2, Valve Corporation has released an additional level and an additional "expansion" sequel. The level, "Lost Coast," takes place between the levels "Highway 17" and "Sandtraps" and is primarily a showcase for high dynamic range imaging (HDR) technology. The "expansion" sequels, Half-Life 2: Episode One and Half-Life 2: Episode Two taking place shortly after the events of Half-Life 2, with the player taking on the role of Gordon Freeman once again and with Alyx Vance playing a more prominent role and expanding the mysteries surrounding the G-Man and the Vortigaunts. Additionally, one further "episode" is set to be released in the future, dubbed Episode Three; being the last expansion, "in a trilogy". In an interview with Eurogamer, Gabe Newell revealed that the Half-Life 2 "episodes" are essentially Half-Life 3. He reasons that rather than force fans to wait another six years for a full sequel, Valve Corporation would release the game in episodic installments. Newell admits that a more correct title for these episodes should have been "Half-Life 3: Episode One" and so forth, having referred to the episodes as Half-Life 3 repeatedly through the interview.

It was confirmed in April 2006 that Half-Life 2: Episode Four was in production, and that it would mark the start of a new story arc. Furthermore, it was confirmed that Episode Four was under development by a third-party studio under Valve Corporation's supervision.

Since the release of the Source engine SDK, a large number of mods have been developed by the Half-Life 2 community. Mods vary in scale, from fan-created levels and weapons, to partial conversions such as Half-Life 2 Substance and Smod (which modify the storyline and gameplay of the pre-existing game), and Garry's Mod (which allow the player to experiment with the physics system in a sandbox mode), to total conversions such as Dystopia or Empires, which transforms the game from a first-person shooter into a real-time strategy game. Some mods take place in the Half-Life universe; others in completely original settings; while some are tributes to other games, such as GoldenEye: Source, a recreation of GoldenEye 007, or Resident Evil: Twilight, based on the Resident Evil series. Many more mods are still in development, including Neotokyo, the episodic single player mod MINERVA, and Insurgency, which focuses on realistic modern infantry combat.

Valve Corporation's Half-Life: Source was a direct conversion of the original game to the Source engine. Black Mesa, originally named Black Mesa: Source, is an unofficial mod under development which takes the more ambitious route of attempting to fully recreate the original Half-Life from the ground up using improved graphical assets and effects, while maintaining the original storyline and level design.

Cuts
The book Half-Life 2: Raising the Bar revealed many of the game's original settings and action that were cut down or removed entirely from the final game. Half-Life 2 was originally intended to be a far darker game with far grittier artwork where the Combine were more obviously draining the oceans for minerals and replacing the atmosphere with noxious, murky gases. Nova Prospekt was originally intended to be a small Combine rail depot built on an old prison in the wasteland (the depot model remains in the game, visible from the beach and trash compactor). Eventually, Nova Prospekt grew and grew from a stopping-off point along the way to the destination itself.

Half-Life 2 was also originally intended to be much more diverse in settings. Parts of the book detail how Gordon would fight alongside characters such as Odessa Cubbage, albeit under a different name and in a different place, as well as fighting together with Colonel Vance - a character that was later merged with Eli to become Doctor Eli Vance - and Vance's forces. In addition, the player was to follow a vastly different journey than what is in the final release.

Other cuts from the game included a drivable personal water craft and additional weapons. Weapons cut included the OICW seen in an E3 demonstration video and two different models of the gravity gun or Physgun, which is seen in another E3 video, also depicting a level cut from Ravenholm, dubbed "Traptown."

It remains unknown if most of the cut Half-Life 2 scenes will eventually be completed and released, or if they are lost forever. A removed section of the original Half-Life was eventually released as the Half-Life: Uplink demo; a similar situation was in place with the HDR technology demo, Lost Coast, which was based on a scene that was cut from the sequel. It is possible that more removed sections of HL2 will be seen in future expansion packs.

Some of the cut content is available in a work-in-progress mod called Missing Information, constructed using the leaked Half-Life 2 betas as a basis. In addition to several cut weapons, the mod also includes a level set on the stranded icebreaker Borealis and the E3 demonstrations. This mod has not been sanctioned by Valve, being described as "illegal content," and official permission has not been given for the redistribution of modified versions of the original leaked material.

Another mod called "Lost Generation" is aiming to create something similar to Missing Information.

Soundtrack
All listed tracks have been composed by Kelly Bailey. Purchasers of the Gold Package of the game were given (among other things) a CD soundtrack containing nearly all the music from the game, along with three bonus tracks. This CD is not available for separate purchase.
 * (Note: Many of the tracks were retitled and carried over from the Half-Life soundtrack; The names in parentheses are the original titles. Tracks 32, 34, 41, and 42 are remixes.)

Tracks 16, 18 and 42 are bonus tracks that are exclusive to the CD soundtrack. Tracks 44 to 51 are tracks from the game that did not appear on the soundtrack CD.

Official

 * Official Half-Life 2 website
 * Steam homepage

Speedruns

 * Half-Life 2 speedrun: speedrun video of the entire game without using shortcuts (03:02:54).
 * Half-Life 2 done quick: speedrun video of the game finished as quickly as possible by using all possible shortcuts and exploits/tricks (01:42:18). A tricks, glitches and outtakes video is also available.

General resources

 * Valve Developer Community; a wiki made by Valve to aid in the editing of Half-Life 2.
 * HL2Files: for Half-Life 2 modifications, maps, sound packs, videos and other downloads.
 * Half-Life 2 mods and modding tutorials at Mod DB.
 * sourceWiki: for Half-Life 2 mod developers.
 * Planet Half-Life: a Half-Life/Half-Life 2-related resource website including news, reviews, screenshots, etc.
 * Halflife2.net: Comprehensive Half-Life/Steam centric website and large Half-Life 2 community.
 * HLFallout.net: Another popular Half-Life 2/Steam fansite with news, reviews and screenshots