Half-Life 2

Half-Life 2 is a first-person shooter computer game and the highly anticipated sequel to Half-Life developed by Valve Software. It received mainstream media attention when the game's source code was leaked to the Internet in September 2003. Valve sent a release candidate to its publisher, Vivendi Universal, on September 15, 2004; the game went gold on October 18, and was released on November 16, 2004, just over 6 years after the October 1998 release of Half-Life. A single-disc demo version was later made available in December at the web site of graphics card manufacturer ATI, who teamed up with Valve for the game. An Xbox version was confirmed in early 2003, but in-game pictures did not show up until the May 2005 issue of Official Xbox Magazine, which stated that Half-Life 2 would be single-player only and would release summer 2005, Xbox Live details were unconfirmed.

Overview

Singleplayer

The original Half-Life largely took place at a remote underground laboratory called the Black Mesa Research Facility. In the course of conducting an experiment, researchers at Black Mesa accidentally cause a "resonance cascade", which opens a doorway to an alien world (Xen) and releases a flood of strange and deadly creatures. The player acted as Gordon Freeman, one of the research scientists, and guided him in his attempt to escape the facility. Half-Life 2 picks up the story an indeterminate number of years after the Black Mesa incident in 'City 17', which seems to be somewhere in Eastern Europe.

At the start of the game, the mysterious G-Man speaks to Gordon Freeman. Freeman then finds himself riding a train into City 17, unarmed and without his HEV suit. Details begin to slowly emerge: City 17 is under the rule of a totalitarian Administrator named Dr. Breen, who coincidentally is the former administrator of the Black Mesa Research Facility. Breen is merely a puppet ruler, however, carrying out the will of the aliens known as the Combine. During the Black Mesa incident in Half-Life, the enormous amounts of energy emitted by the resonance cascade attracted the attention of the Combine. They mounted a brutal assault on humanity in which the forces of Earth were completely overwhelmed in seven hours (which is, appropriately enough, referred to as the Seven Hours War). The Combine now has near-absolute control of the entire planet, with only a few pockets of human resistance remaining. Dr. Breen enforces his rule (and, by extension, the Combine's rule) through armies of intimidating "Civil Protection" units (also called "Metropolice" or "Metrocops") and Combine soldiers.

Half-Life 2's gameplay, like that of the original Half-Life, is divided into titled chapters:

• Point Insertion – Gordon arrives in City 17, weaponless and without his HEV suit, and meets up with old friend Barney Calhoun, a security guard from Black Mesa. Barney has infiltrated the Civil Protection force, working for the resistance.
• A Red Letter Day – Gordon meets Alyx Vance (the daughter of Dr. Eli Vance, a fellow scientist from Black Mesa). Alyx takes him to Dr. Isaac Kleiner, Gordon's mentor from MIT and colleague at Black Mesa). Kleiner attempts to teleport Gordon to Eli's laboratory (called Black Mesa East) on the far side of the city, but Dr. Kleiner's pet headcrab "Lamarr" wrecks the teleporter. Gordon must find another way to reach Dr. Vance's facility.
• Route Kanal – While making his way along the city's canals, Gordon finds a resistance base populated by both humans and Vortigaunts, who are now allies. The resistance provides Gordon with an air boat, allowing him to travel to Black Mesa East much more quickly.
• Water Hazard – The air boat is spotted by Combine troops and pursued by a hunter-killer assault helicopter. At another resistance base, a Vortigaunt affixes a weapon to the air boat capable of downing the troublesome copter.
• Black Mesa East – Gordon arrives at Eli's lab and meets Dr. Judith Mossman. Alyx shows gives him a new weapon called a Gravity Gun and demonstrates its use. Suddenly the lab is attacked by Combine soldiers, forcing Gordon to escape along an old tunnel leading to Ravenholm.
• "We Don't Go To Ravenholm..." – Gordon quickly discovers why Ravenholm was abandoned: the city has been overrun with headcrabs and "zombies". Father Grigori, a slightly demented priest and likely the last human resident of Ravenholm, helps him survive the dangerous streets and escorts him to an abandoned mine entrance. The mines lead Freeman to the dockyards outside City 17.
• Highway 17 – Gordon finds another resistance base under assault by Combine troops. Alyx tells him that Eli has been captured by the Combine and is being held in Nova Prospekt, an old maximum-security prison. Gordon travels the coast road in a dune buggy towards Nova Prospekt. The journey is made more difficult by the fact that it's spawning season for insectile alien creatures known as antlions, which swarm the area.
• Sandtraps – Gordon arrives at the resistance base at Lighthouse Point and must continue the rest of the way to Nova Prospekt on foot. Antlions lie hidden underground, emerging to attack at the slightest vibrations. Gordon must cling to the rocks and avoid stepping on the loose sand that alerts the ferocious aliens. After narrowly defeating an enormous "Antlion Guard", Gordon is given bugbait: a gland filled with pheromones that prevents the smaller Antlions from attacking him.
• Nova Prospekt – Finally reaching the old prison, Gordon searches the facility for clues to Dr. Vance's whereabouts. The antlions' assistance helps to even the overwhelming odds against him.
• Entanglement – Gordon joins forces with Alyx again, and together they find both Eli and Dr. Judith Mossman, who is apparently a Combine agent. While Gordon and Alyx are distracted by a Combine assault, Mossman teleports herself and Eli into the Citadel, the monolithic base of operations for the Combine. Alyx and Gordon barely manage to teleport themselves to Dr. Kleiner's lab before the teleporter is destroyed.
• Anticitizen One – A strange malfunction in the equipment has caused Alyx and Gordon to arrive at Dr. Kleiner's lab a week after they teleported. Meanwhile, Gordon's struggles against the Combine have brought new life to the resistance, plunging City 17 into turmoil. A squad of resistance fighters led by Gordon travels towards the Citadel to free Dr. Vance while Alyx helps Dr. Kleiner escape the lab.
• "Follow Freeman!" – After rescuing Barney, who has been pinned down by snipers, Gordon shuts down a suppressor field blocking access to the Citadel. A pack of incredibly powerful Combine war-machines, the Striders, attack until they are finally destroyed by RPG fire.
• Our Benefactors – Gordon enters the Citadel through an underground passage. Faced with a dead end, he has no choice but to enter a rail-driven containment apparatus. After a long trip through the Citadel, all of Gordon's weapons are destroyed by a Dark Energy-powered "confiscation field". Only the Gravity Gun survives, probably because it is based on Xen technology, and is made incredibly powerful. It is now capable of manipulating much larger objects as well as instantly killing Combine forces. Armed only with the newly augmented Gravity Gun, Gordon wreaks havoc upon the Citadel until he is again faced with a dead end. Once more, the only way to progress is to voluntarily enter a containment apparatus.
• Dark Energy – The device brings him face-to-face with Dr. Breen, who takes the Gravity Gun while Gordon is immobilized. Dr. Judith Mossman is with Breen, and he summons Eli and Alyx, who are being held in similar devices. As Breen threatens Gordon, Judith finally turns against him: she had only "betrayed" the resistance to get an opportunity to infiltrate Breen's inner circle. He manages to escape and flees towards a huge teleporter that will take him to the Combine's world. Freed, Gordon and Alyx pursue him and destroy the teleporter, triggering a massive explosion.

Two distinctive elements from the original Half-Life are preserved: Freeman never speaks, and the entire game is viewed through his eyes. Some players have complained about these holdovers, since they effectively limit how much of the backstory is explained. The lack of cut-scenes mean that the player never sees what happens or has happened in Gordon's absence; additionally, it would seem natural for Freeman to have a great deal of curiosity as to what has happened since the Black Mesa incident. Although these are certainly intentional devices on the part of Valve Software, some feel that it is very frustrating to only learn the story in small bits and pieces throughout the game. It could be said in Half-Life that the player's bewilderment is meant to mirror Gordon's during the chaotic events following the resonance cascade and alien invasion. By the opening of Half-Life 2, however, Gordon has proven that he can survive in a strange and hostile environment, and should therefore be at least somewhat more level-headed and inquisitive.

Adding to the sense of confusion is the fact that while most of Gordon's former coworkers from Black Mesa have visibly aged in the interim, Gordon has (presumably) not; however, only a few passing references are ever made regarding this. (The game never specifies how many years have passed between Half-Life and Half-Life 2, but many players agree that it is likely close to 10 years.)

The ending of Half-Life 2 is also very similar (and similarly frustrating) to that of the original: after completing a difficult task against overwhelming odds, Gordon is "extracted" by the G-Man, wielding incredible but unexplained powers. The player is smugly congratulated and told that further assignments should follow. The fate of many of the major characters, such as Alyx, Eli, and Judith, are unexplained. Very few, if any, of the questions raised by Half-Life are answered, and several new ones are presented. Some players also complained that they expected more insight into the identity and nature of the G-Man. (These complaints, of course, only prove that Valve was successful in creating anticipation for a third game immediately after the release of the second, or perhaps the expansion pack, Half-Life 2: Aftermath.)

Enemies

There are several types of enemy in Half-Life 2, ranging from the headcrabs of the original to the highly skilled and heavily armed Elite Overwatch soldiers.

Headcrabs

The headcrab was perhaps the most distinctive enemy in Half-Life, inspiring countless startled jumps as they hopped out of darkened hiding spots. They return in Half-Life 2 to again impede the player's progress, but there are now three different kinds of headcrabs, each with their own special traits.

• Headcrabs

The "ordinary" headcrab is much the same as it was in Half-Life; they creep along in search of prey and when close enough, will leap and deal a small amount of damage. They can easily be dispatched with a few pistol shots, but they are frequently positioned near a corner, the top of a ladder, or in some other cramped location where can attack quickly before being spotted. Occasionally the headcrab's presence is given away by its distinctive gargling/chattering sound.

• Fast Headcrabs

First appearing in the chapter We Don't Go to Ravenholm..., the fast headcrab's name aptly describes its speed. Similar in appearance to a normal headcrab, it has longer legs and moves much more rapidly, making it an elusive target. The fast headcrab is no stronger than an ordinary one, however, and can be killed with a few bullets (provided the player manages to hit it).

• Poison Headcrab

Poison headcrabs are also first seen in We Don't Go to Ravenholm... They have a loud, distinct screech not unlike a cat's, and sport a dark gray mottled back with a meaty maw opening. If it succeeds in its "bite" attack, the player's health immediately drops to 1. The player's health slowly replenishes until it is nearly at its former level. Poison headcrabs alone cannot kill the player, but other enemies can easily do so while the player is "poisoned".

Barnacles

Much the same as in the original Half-Life, barnacles will latch onto nearly any object that come into contact with their long hanging tongues. The prehensile tongue grabs the object, whether living or inanimate, and draws it up towards the creature's maw to be crushed. The barnacle is relatively easy to kill, succumbing to a few pistol shots or a blast from a shotgun. A novel new way to kill barnacles in Half-Life 2, however, is to "push" an explosive barrel into its grasp, then ignite the barrel with gunfire just before it reaches the creature's mouth. This tactic, if executed properly, can take out several barnacles within a small area.

Zombies

Zombies, humans that have been overtaken by headcrabs, were more a source of scares than a serious threat in Half-Life. There are some new "varieties" in Half-Life 2, however, making for some dangerous enemies. The new zombie variants correspond to the new headcrab types. One common trait between all the zombies, and a difference from the original game, is that a headcrab will sometimes detach itself from its zombie just before death. Since zombies often appear in groups, it can be difficult to monitor each individual creature to make sure that its headcrab is also dead.

• Zombies

The "ordinary" zombies are slow-moving, fairly weak, and generally easy to deal with. Their only advantage is when they appear in large numbers, in which case they attempt to swarm the player and inflict great damage with their claws. One additional "feature" is that occasionally a zombie can survive being cut in half; the upper torso will laboriously pull itself towards the player.

• Fast Zombies

Humans who have been "possessed" by fast headcrabs will take on the abilities of their master. They appear much thinner yet more muscular than normal zombies, possess great speed, and display incredible jumping abilities.

• Toxic Zombies

Toxic zombies are, without question, the most difficult type of zombies to deal with in Half-Life 2. They are incredibly resilient: on advanced difficulty levels, they can survive multiple crossbow bolts to the chest (in comparison, even Overwatch elite troops succumb to a single bolt). Unfortunately, their defensive capabilities are matched by a very potent offense. In addition to the standard clawing attack, toxic zombies host numerous poison headcrabs on their back. They are capable of throwing these headcrabs at the player from great distances.

Unfortunately, killing a poison zombie causes its "passengers" to detach from their host. The optimal way to deal with both the zombie and its attached headcrabs is by setting it on fire; this can be done by shooting oxygen cylinders or flammable barrels near the creature.

Combine Forces

For the bulk of the game, the "transhuman" forces of the Civil Protection and the Overwatch are the player's primary nemeses. The Overwatch are somewhat analogous to the Commandos in Half-Life but are generally smarter and better armed. They usually attack in groups of four or five, especially in open areas.

• Civil Protection

The Civil Protection forces are essentially cops patrolling City 17. They brutally suppress any display of human resistance or disobediance. Civil Protection officers wear only minimal armor, and can only survive a few strikes by light weapons. They can carry pistols and SMGs.

• Overwatch

The Overwatch is nearly omnipresent throughout the last two-thirds of Half-Life 2. The main difference between the Overwatch and the Civil Protection forces is their improved body armor and better weaponry; they wield SMGs, pulse rifles, and shotguns, and hurl grenades with great skill and enthusiasm. They are also better organized than the CP troops, and will use squad tactics to gang up and attack the player from multiple directions at once.

• Overwatch Elite

The high-end Overwatch forces are known only as Overwatch elites, and appear late in the game within the Citadel. These soldiers are outfitted in white armor featuring a red "optical sensor" and wield pulse rifles. They are also able to use the pulse rifle's scondary-fire mode, which sends out an unstable, highly destructive energy core.

Antlions

Antlions are relatively mindless but deadly nonetheless, if only because of their numbers. These insect-like creatures are found near the coastal areas of Highway 17, and will emerge from the ground when disturbed by any seismic disturbances (i.e. footsteps or a vehicle). They attack at close range with their powerful mandibles and can quickly overwhelm the player.

Antlion Guards

This subspecies of antlions are more enormous and ferocious than the more common variety. Unlike their smaller relatives, they cannot fly, but rely instead on vicious biting attacks and trampling runs. They are decidedly powerful creatures, and can withstand a large amount of damage.

Antlion Guards maintain control over other antlions primarily through pheromones. The gland that emits these pheromones can be extracted and used to exert a similar control over the antlions, providing a nearly-inexhaustible supply of flying troops.

Manhacks

These little drone robots are relatively fragile and deal little damage individually, although in sufficient numbers they can pose a serious threat. Civil Protection and Overwatch soldiers carry manhacks, which when released, fly unpredictably around sporting razor-sharp spinning blades.

Gunships

Combine gunships have a distinctly organic look, and it is unclear whether they are piloted vehicles or discrete alien entities. Regardless, they are one of the most daunting foes of Half-Life 2. They are capable of "stalking" the player, doggedly following overhead and pounding the area with damaging turret fire. The heavily-armored gunships can only be destroyed by laser-guided RPG rounds; these missiles must be steered past the gunship's defenses before they can strike the craft.

Striders

These hulking tanks, which are apparently organic, are capable of dealing massive damage to human resistance forces. They are armed with a turret similar to that of a gunship and also wield an energy beam that can punch through walls. Humans struck by any of their three gigantic legs are instantly crushed.

Weapons

Half-Life 2 contains several weapons, which are not all available in all modes.

Standard weapons

The following weapons are available in the normal singleplayer mode. All these are also available in Half-Life 2 Deathmatch (HL2DM) except where noted.

• Crowbar: the mêlée weapon of Half-Life, and also the first weapon available. In HL2DM the crowbar is weaker but faster than the Stunstick.
• Gravity Gun: Officially called the Zero Point Energy Field Manipulator, the Gravity Gun is a tractor beam–like weapon that does not use any ammo. The primary fire can repel most inanimate objects, allowing these objects to be moved to clear a path, or to harm enemies. The burst itself can also harm some weaker enemies, such as headcrabs. The secondary fire can attract most inanimate objects up to a limit (cars and heavier objects cannot be "pulled"). Held objects can then be launched by using the primary fire, or be used as shields. In HL2DM, the launched objects usually kill instantly. The Gravity Gun heavily utilizes the game's physics engine, and it was originally a tool used by the developers to experiment with and test the physics engine.
• Dark Energy Gravity Gun: late in the singleplayer game, the Gravity Gun receives an infusion of "Dark Energy" from a Combine beam. From that point on, it can also grasp or repel living creatures (killing instantly), and pull heavier inanimate objects. A replacement of the normal Gravity Gun, it is not available in other parts of the game or in multiplayer.
• USP Match 9mm: the first gun available, it is relatively weak but very accurate.
• .357 Magnum Revolver: the second handgun available, it is more powerful and accurate than most other weapons, but ammo for it is quite scarce. It's effective against combine soldiers and zombies, but since ammo is so scarce is should only be used at specific targets.
• MP7A1 Submachine Gun: the first rapid-firing weapon received, this is the primary weapon for close combat. It has a 45 round magazine with 225 rounds in reserve. Secondary fire launches a grenade that detonates on impact. It is also modeled after the real MP7, but with an added grenade launcher, which is purely fictional. (Secondary "tube" on the model)
• Overwatch Standard Issue Pulse Rifle: a powerful assault rifle used by the "Overwatch" (Combine soldiers). The primary fire launches a burst of energy which usually kills with one or two shots. The secondary fire shoots an energy orb, which bounces around the environment for 3 seconds, disintegrating enemies on contact before exploding. The energy orb has caused some stir among HL2DM players, who argue that it is too powerful. The orb can be caught with the Gravity Gun and then launched at enemies.
• Shotgun: the shotgun does high damage at close range, but its broad fire cone makes it weak at a distance. Its secondary fire shoots two rounds at once. This weapon is modeled after the real SPAS-12 shotgun.
• Crossbow: the crossbow is a sniper weapon with high damage and accuracy, but with a slow rate of fire and reload time. Secondary fire activates a zoom mode. The launched bolts are affected by gravity.
• Rocket Launcher: this weapon fires rockets which must be guided it in flight using a laser pointer. Up to three rockets can be stored in the magazine.
• Grenade: a frag grenade that explodes a few seconds after being thrown. Secondary fire rolls the grenades over the floor instead of throwing them in an arc. Thrown grenades can be caught and relaunched with the Gravity Gun.
• Pheropod ("Bug Bait"): these are small pods of pheromones which can be used by the player to command swarms of antlions. The primary fire throws the pods and commands the antlions to go to the target. The secondary fire squeezes the pod to recall the antlions. Pheropods are ineffective against the larger, more aggressive antlion guards. Thrown pods stun enemies for approximately 5 seconds, but do no damage (unless you count the hordes of ravenous antlions it summons to the affected enemies). This weapon is not available in HL2DM.

HL2DM weapons

HL2DM includes two weapons which are not available in the singleplayer game:

• Stunstick: in the singleplayer game this mêlée weapon is only available to Combine Civil Protection units. It inflicts no damage, but stuns the player: the view wobbles and goes momentarily red. The stunstick has been introduced in HL2DM, where it does inflict damage. It is more powerful than the crowbar, but much slower.
• SLAM: the SLAM (Selectable Lightweight Attack Munitions) originally only appeared in the beta version of the Half Life 2, and was left out of the single player game. This mine weapon is now included in HL2DM. The primary firemode varies depending on whether the player is facing a surface or large physics object, or is targeting open space. When facing a surface the weapon will stick to the surface and emit a laser beam, which will detonate the SLAM if it is broken. When not facing a surface the mine is thrown, but does not explode. Multiple mines can be deposited. The secondary fire then becomes a detonator for all thrown mines. Mines not attached to surfaces can be repositioned with the Gravity Gun: when launched they become light explosives which can be used to knock physics objects into other players.

Additional weapons

• Overwatch light machine gun: A modified version of the Pulse Rifle, this stationary weapon has an unlimited supply of ammunition and does not have to be reloaded. It is usually found in an entrenched position, and can be operated by both the player and Combine troops.
• Overwatch attack helicopter turret: this armor-piercing, airboat-mounted weapon is used near the end of the Water Hazard sequence, and can destroy Combine vehicles. It is the same weapon used by Combine helicopters. It constantly replenishes its own ammo at a rate slightly slower than its firing rate, and has a maximum capacity of 100 rounds. This weapon can also be fired when zooming.
• Tau cannon (vehicle-mounted): This weapon, attached to the buggy, functions similarly to the Tau Cannon from Half-Life. It fires laser-like beams which can optionally be charged with the secondary fire button for increased power.

• Annabelle: "Annabelle" is the modified shotgun used by Father Grigori in the Ravenholm chapter. It has more power per shot than the standard shotgun, with a lower rate of fire, and is also very effective at long range. The only way to acquire the Annabelle is to open up the console and type "Give weapon_annabelle". (The Annabelle uses ammo from your .357 Magnum so conserve ammo)
• Alyx Gun: Alyx Vance has her own special weapon, which can be obtained by typing "give weapon_alyxgun". This may not always work and may cause stuff you don't want to happen.

Cuts

Interestingly, a recent book called Half-Life 2: Raising the Bar (ISBN 0761543643), revealed that the Nova Prospekt chapter was originally much longer, but subsequently cut down to just one scene. Many hints and conversations that answered several questions players have asked were also cut. Raising the Bar shows scripts of these scenes, screenshots, and even fully rendered models, indicating the section was cut late in development. Parts of it survive as glimpsed scenes during the last section of the released game.

Promotional shots and gameplay videos released before the game became available showed parts of these scenes, and also showed enemies which do not appear anywhere in the final game, such as a hydra-like enemy. The hydra was apparently cut because its AI proved troublesome: it looked great when attacking NPCs, but it was not felt to be a convincing enemy for the player.

It remains unknown if the cut Half-Life 2 scenes will eventually be completed and released (possibly as an expansion pack such as Half-Life 2: Aftermath) or if they are lost forever. A similarly cut scene for Half-Life was eventually released as the Half-Life: Uplink demo.

Multiplayer

When Half-Life 2 was released, its only multiplayer component was Counter-Strike: Source. On November 30, 2004, Valve released the Half-Life 2 Deathmatch component (HL2DM) along with the full SDK as a free download to all Half-Life 2 owners.

Half-Life 2: Deathmatch currently has seven "official" maps, some of which are based on areas from the single-player game: "dm_overwatch", "dm_lockdown", "dm_steamlab", "dm_underpass", "dm_powerhouse", "dm_resistance" and "dm_runoff". "Dm_overwatch" is based on the single-player chapter "Follow Freeman!", while "dm_lockdown" is based on the Nova Prospekt chapter. "Dm_steamlab" is an original map loosely based on the Half-Life Deathmatch (HLDM) map "datacore", while "dm_runoff" was inspired by the popular HLDM map "dm_crossfire". Valve also ran a mapmaking contest within the community, announcing the winners in placement order as "dm_underpass", "dm_resistance", "dm_powerhouse" and "dm_avalon" as a honorable mention.

The map "dm_steamlab" was released on 17 February 2005, with three new weapons: the Crowbar, the Stunstick and the S.L.A.M. The S.L.A.M. is a mine-type device, functioning in the same way as a proximity mine. It can be attached to walls when it emits a laser beam, which when broken will detonate the mine. A S.L.A.M. mine can also be detonated on demand by the player who placed it. Both the Stunstick and Crowbar behave as they did in the single-player version of the game.

The goal of Deathmatch is for the player to kill as many other players as possible, using a variety of means. The player spawns with a gravity gun, pistol, sub-machine gun and grenades. All weapons aside from the pheropod (also known as bugbait) are available to be collected around the maps. Players can be killed by gunfire, explosions, or by being hit by objects fired using the gravity gun.

Some players have expressed disappointment in HL2DM, specifically concerning the Gravity Gun. The seven official maps for HL2DM are filled with objects which can be carried by the gravity gun, leading to their near-exclusive use. This is compounded by the damage these items can deal when hit by them, which is arguably far greater than any other conventional weapon. Instead of being deathmatch, some players argue, HL2DM is an exercise in "lifting and chucking." [1] However, there are arguably just as many players for whom the novelty of annihilating enemies by blasting them with barrels, computer monitors and even cars will never be exhausted. The counter to the incredible power of the Gravity Gun is the relatively slow speed of its projectiles; indeed, the argument is not dissimilar to abuse hurled at players who camp with sniper rifles or RPG's. It is common for a player to immediately blame some factor beyond his or her control for a defeat.

Building barricades is another Deathmatch strategy that has proven both popular and loathed. By using the Gravity Gun to place a large amount of objects in chokepoints such as stairs or tunnels leading to strategically important locations, the player defending the barricade will have a huge advantage over his opponents. Dealing with the barricades themselves is simple enough, but the distraction they provide is enough to render a player highly vulnerable against opponents. For example, the most popular camping spot in "dm_overwatch" is near the actual overwatch, a Combine lookout post. This spot is easy to defend since players can block the only way leading to the overwatch with objects. This results in a stalemate in the favour of the camper, who can indefinitely "camp" the overwatch using a RPG that is conveniently placed nearby.

Game engine

For Half-Life 2 Valve developed a new game engine called Source, which handles the game's visual, audio, and AI elements. Environmental physics calculations are handled by the licensed Havok middleware engine. As usual, to utilize the new graphics and visual effects, players require fairly recent video cards, giving GPU manufacturer ATI Technologies an opportunity to partner with Valve on a joint product release [2], which, unfortunately, was spoiled by the product delay. Half-Life 2 requires powerful hardware in order to run with all visual and audio effects enabled, but due to the Source engine's ability to scale according to the level of the hardware, a modern PC system is not required. The Source engine's interactivity promised to tie emergent gameplay with the scripted sequences that Half-Life was already known for, but few examples of emergent behaviour have been displayed. Valve has licensed the Source engine to other developers, on the condition that their games were delayed until the release of Half-Life 2.

Like with its predecessor Half-Life, Half-Life 2 is expected to become a base for many modifications, or mods. Many of them are sequels of original Half-Life mods. Valve has also included Counter-Strike: Source (Counter-Strike for Half-Life 2) in the retail version of Half-Life 2. Day of Defeat: Source will also be released, and is currently being pre-sold with premium Half-Life 2 Steam packages.

One of the more notable features of Half-Life 2 is the unique ability of the characters to simulate emotions and facial speech movements on the fly. The facial animation technology is language independent, with facial features being created automatically based on audio files and speech transcripts. According to Valve, forty-two "facial muscles" are simulated for this. Another feature, courtesy of the Havok physics engine, is the increased interactivity of the levels with every object having unique mass, density, buoyancy, and other properties which make its interaction with the player, other objects and the environment more realistic.

Additionally, when coupled with Steam, the engine can be easily upgraded to include many new computer graphic technologies. One such example is High dynamic range imaging, and Valve will release a free outdoor level based on Highway 17 featuring this technology, known as "Lost Coast". Perhaps, in the future, other new graphic technology may be included, either to increase performance, draw distance, or increase the appearance of the graphic.

Steam content delivery system

Integral to Half-Life 2 is the Steam content delivery system developed by Valve Software. This allows customers to purchase games (or any other software) directly from the developer and have it downloaded directly to their computer. This system also allows "micro updates" to games – games are continually updated and only the most recent version is allowed to be run. This makes it much harder to hack the game to introduce cheats or to play online with a free 'pirated' copy. All users playing a single game must also have an account on the Steam servers to play the game. Steam is also used for finding and playing multiplayer games.

Some users have had numerous problems with Steam, enough so that the delivery and multiplayer client is a well-marked part of the game, in some cases enough to prevent a reviewer to recommend the game, and in almost every case enough to lower the review score. Long download times, updates and internet checks that are sometimes unnecessary characterize some negative views of the Steam client.

A 1 GB portion of Half-Life 2 became available for pre-load through Steam on August 26, 2004. This means that customers could begin to download encrypted game files to their computer before the game is released. When the game was released in the shops, 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, along with several subsequent portions of the game being made available, to ensure all customers had a chance to download the content before the game is released.

Release problems

On November 16, 2004, Half-Life 2 was officially released. While the launch was mainly regarded as successful, a significant number of buyers (both through Steam and retail) initially found themselves unable to play the game, due in part to the overloading of Valve's Steam system.

Ideally, a user would install Half-Life 2, authorize his or her copy of the game, and be able to play. However, the skepticism felt by many gamers towards this was proven well-founded: the Steam authorization servers were unable to smoothly process the high load (a similar phenomenon also strikes servers of very popular MMORPGs). Many people, whether purchasing the game through conventional retail channels or through Steam, found themselves unable to play the game they had bought.

While many players and reviewers complained about Valve's arguably heavy-handed implementation of Digital rights management (DRM), the public was generally more tolerant towards its use in Half-Life 2 than they were to Microsoft's Windows XP product activation scheme or the DRM system used by Intuit, Inc.'s TurboTax software.

Another blemish on HL2's release record was the "No Counter-Strike" install error. If a user does not wish to install Counter-Strike: Source, he or she will encounter an error approximately 80% of the way into the installation procedure. Only if the user installs Counter-Strike will the installation complete (after which it can be specifically uninstalled). Note that while not all users experienced this error, the error was so commonplace that a warning was issued before the game was released.

Further, some users have reported game crashes when HL2 initiates its auto-save feature, as well as audio stuttering. Patches are periodically released by Valve which attempt to correct these issues. The initial patch, released in December 2004, fixed the audio stuttering but also forced reduced the game's performance for some players, either through a lowered frame rate or lowered resolution. Some players report that the patch has reduced the game's overall performance and also failed to reasonably correct the audio stuttering. Other games using the Source engine have not experienced this audio stuttering to the degree being reported in Half-Life 2.

However, even on the best of systems the auto-save feature can cause a "freeze" when it is triggered, often at important points of the game—during this time the game saves all applicable information about the player's current progress in the game so they can start off from the same point. This lag can be quite disruptive to play, but can be avoided by changing hidden settings in Half-Life 2's configuration file. A patch released in January 2005 decreased the stuttering during game save in many cases.

An update was released on November 30, 2004 which inadvertently prevented scores of customers from launching the game. A minor update was quickly launched to resolve the issue. The update added the multiplayer Half-Life 2: Deathmatch, which had been noticeably absent from the original release.

On December 10, 2004, Valve released a Steam update that solved a "disc in drive incompatibility error" by removing the Securom disc check routine. This change also allowed users to play the game without the game CD or DVD in their drives.

To play either single-player Half-Life 2 or HL2DM, players must create an account on Steam. This process normally takes only seconds, but times of multiple hours continue to be reported. However, anyone without internet access is effectively barred from registering and playing the game. Although a majority of players will have internet access, it still affects a significant number of prospective consumers. Steam used to require connection to the authentication servers every few days to refresh the authentication ticket on the player's machine, despite what Doug Lombardi described in an interview prior to release of Half-Life 2. However, this was fixed in an Steam update on December 14, 2004. The authentication ticket expiry period has been extended to several weeks.

Post-release piracy

On the day the game was released a cracked version which did not require Steam or a CD appeared on the Internet. Despite being a single-player game, normal copies of Half-Life 2 require online activation through Steam in order to play. This enabled Valve to track users by their authentication key. On November 23, a week after the game's release, Valve announced that they had disabled 20,000 Steam accounts that had used a key that was being distributed by warez sites on the Internet. On December 22, a further 30,000 Steam accounts were disabled, as announced on another forum post.

Development controversies

Source Code Theft

Half-Life 2 was merely a rumor until a strong impression at E3 in May 2003 launched it into levels of hype only equalled by Doom 3 at the time. It was forecast to come out in September 2003, but it was delayed several times. This pushing back of HL2's release date came in the wake of the cracking of Valve's internal network, through bugs in Microsoft Outlook, resulting in the theft of the game's source code in early September 2003.

The source-code theft had more of an effect on morale for the developers than it did on the schedule—it was later revealed by both Valve CEO Gabe Newell and PR man Doug Lombardi that the September 2003 release date was 'aggressive' and could not have been met even if the theft had never occurred. Many gamers were not surprised by the early delays, recognizing that Valve's first public mention of the game came just four months before its intended release date.

In June 2004, Valve Software announced in a press release that the FBI had arrested several people suspected of involvement in the source code theft.

Beta leak

Roughly at the same time as the source code leak, a beta version of HL2 was leaked to the net. Initial claims that the leak was a hoax turned out to be in error as the beta quickly spread widely and was verified to exist by a large number of people. The beta contained many unfinished parts of the game in a partially, albeit buggy playable state, as well as some of the tools used to create game content. This beta leak was also the origin of the "physgun" weapon – a tool which could be used to interact with the physics objects in the game, such as ragdolls, as well as to weld them together. The "physgun" has since been recreated in the game by various mods such as JBMod and Garry's Mod.

Going gold hoax

On August 27, 2004 a forum post by Gabe Newell from Valve Software said "going gold on Monday". "Going gold" means that the game is finished and simply needs to be pressed onto DVDs and packaged into boxes. This caused much excitement among Half-Life 2 fans but it later turned out that the post was a hoax and was posted by someone who had guessed Gabe's password ("gaben").

Contract dispute regarding Cyber Cafes with Vivendi Universal Games (VUG)

On September 20, 2004, it was revealed by GameSpot that Vivendi Universal Games (VUG) was in a legal battle with Valve Software over the distribution of Half-Life 2 to Cyber Cafes. This is important for the Asian PC gaming market where PC and broadband penetration per capita are much lower (South Korea and Taiwan excepted). Therefore, Cyber Cafes are extremely popular for playing online games for large numbers of people.

According to VUG, the distribution contract they signed with Valve included Cyber Cafes. This would mean that only VUG could distribute Half-Life 2 to Cyber Cafes—not Valve through the Steam system. In November 29, 2004, Judge Thomas S. Zilly, of U.S. Federal District Court in Seattle, WA, ruled that Sierra/Vivendi Universal Games, and its affiliates, are not authorized to distribute (directly or indirectly) Valve games through cyber cafés to end users for pay-to-play activities pursuant to the parties' current publishing agreement. In addition, Judge Zilly ruled in favor of the Valve motion regarding the contractual limitation of liability, allowing Valve to recover copyright damages for any infringement as allowed by law without regard to the publishing agreement's limitation of liability clause.

Motion sickness and field of view

Some complained that playing Half-Life 2 resulted in motion sickness and many attributed the problem to the game's low field of view, which defaults to 75 degrees instead of the more commonly used 90 degrees. While players can increase the FOV through console commands, it can take away the realism, as staring at a monitor about a foot away (the recommended distance) is around 50 degrees depending on the size of the monitor. Additionally, when using 90 degrees, the character's face will get distorted and the levels will seem larger with the player moving through it at high speed.

Interestingly, when the player enters either of the vehicles the FOV is switched to 90 degrees, yet that is where most complained that they experienced motion sickness.

Valve's Bill Van Buren responded to a question on this asked by a fan on the Half-Life2.net forums ([3]) with this response:

We've been rigorously playing and testing Half-Life 2, Counterstrike Source and Half-Life Source for a long time now – and we've found nothing to suggest that the FOV change is a significant factor in causing motion sickness. We have, however, put a great deal of work and attention into reducing the motion sickness that can be experienced in the vehicles in Half-Life 2. During our early playtests, many of us were experiencing motion sickness from driving the buggy and the airboat—especially the airboat. We've done a lot of work on tuning the experience to reduce any ill effects—especially looking at how we manage the players head/view in relationship to the movement of the vehicles. Interestingly, for all of the vehicle sequences we revert back to FOV 90 so that you have more peripheral vision which is helpful when moving at these faster speeds. Even so, some people still do experience some motion sickness effects from long stretches in the vehicles – personally, I find that I am most affected by the intense jarring that occurs when you slam into something in the airboat at high speed – like when you miss a jump or something.

Others attribute the motion sickness to the default refresh rate setting of 60Hz.

Mods, Expansions, and Sequels

There are several mods developed by Half-Life 2 mod teams. These include partial conversions which allows players to manipulate the physics engine or control Striders; mods which expand the story from different points of view; total conversions which introduce completely new settings; and multi-player mods. Several mods are listed in the article Half-Life 2 mods.

Half-Life 2: Aftermath

Rumours about official expansion packs for Half-Life 2 began circulating soon after the game's initial release. UK-based game magazine PC Gamer UK sparked many rumors when they jokingly published an article (incorrectly) reporting that an upcoming expansion pack would allow players to take the role of supporting character Alyx Vance.

Valve has officially announced the first expansion pack for Half-Life 2, which will be called Half-Life 2: Aftermath. While very few details have been revealed, it has been confirmed that the expansion pack will not feature Alyx Vance as a playable character, as is stated in this excerpt from a Eurogamer.net article:

As for where Aftermath is set, and the timeline, it's very much a logical continuation from where Half-Life 2 left off, as Laidlaw explains: "Aftermath deals with the events and issues set in motion during Half-Life 2. You've done critical damage to the Citadel. The whole place is going to go up, taking out City 17 and what's in its immediate radius. You and Alyx are leading the flight from the city getting up close and personal with some of the creatures and sights from the end of the game."

Interestingly, the assumption that Gordon will again be the player character isn't explicitly justified anywhere in the text; it's very possible (and perhaps more likely, given the game's ending) that the player character will be someone else instead.

Half-Life 2: Aftermath is due to be released in "summer 2005" via Steam, but many doubt that it will arrive on schedule in light of the delays Half-Life 2 endured. An article has been released on the upcoming level (and also The Lost Coast singleplayer level, designed to showcase a new lighting technology, and Day of Defeat: Source, a Half-Life 2 conversion of a popular Half-Life mod which Valve later bought) in the UK edition of PC GAMER, issue 148, May 2005.

Sequels

Given the critical and commercial success of both Half-Life and Half-Life 2, many feel that Half-Life 3 is inevitable. However, Valve has not officially announced the start of production, or indeed even plans, for such a sequel. Given that Half-Life 2 was released six years after the original game, some believe that Half-Life 3 is unlikely to appear for several years.

Reviews

Awards

• AIAS 2004 Awards
  • Outstanding Achievement in Art Direction
  • Outstanding Achievement in Animation
  • Outstanding Character Performance-Male
  • Outstanding Achievement in Game Play
  • Outstanding Achievement in Visual Engineering
  • Innovation in Computer Gaming
  • Computer First Person Action Game of the Year
  • Computer Game of the Year
  • Overall Game of the Year
• BAFTA Games Awards Best game
  • Best online game
  • Best action adventure
  • Best PC game
  • Art direction
  • Animation
• 2005 Game Developers Choice Awards
  • Best Character Design
  • Game of the Year
  • Best Graphics
  • Best Technology
  • Excellence in Writing
• Gamespot Best and Worst of 2004
  • Best Graphic, Artistic
  • Best Shooter (cross-platform)
• GameSpy 2004 Game of the Year
  • Best PC overall
  • Best PC action
  • Best PC Graphics
  • Best Character (Dog)
  • Silver for Overall (Cross-platform)
  • Gamer's Choice
    • PC Action
    • PC Multiplayer
    • PC Overall
• IGN The Best of 2004
  • Best First Person shooter (Overall and PC)
  • Best Graphics (Overall and PC)
  • Best Overall Use of Sound
  • Game of the Year (Overall and PC)
• Eleventh Annual PC Gamer Awards
  • Game of the Year 2004

    Note: PC Gamer Games of the Year are ineligible for Best-Genre awards, such as Best Action Game.

  • Best Graphics (in Daylight)

    This was contrasted to Doom 3, which won Best Graphics (in the Dark). Both games had comparably good graphics engines, but where Half-Life's locales were generally well-lit, Doom had very dim lighting. Additionally, Doom was a frightening game, and it was therefore best played in the dark to amplify this effect. The category was something of a joke, and was listed alongside many categories such as Best Use of Mushrooms.

• Spike TV Video Game Award 2004
  • Best PC Game
  • Best Graphics

Related topics

• Half-Life 2 mods
• Vortigaunt
• Combine

External links

• Official Half-Life 2 website
• Steam homepage
• Half-Life 2 demo (1CD)
• MobyGames' entry on Half Life 2
• sourceWiki – For Half-Life 2 mod developers
• Half-Life 2 Wiki. A complete knowledge base and tutorial dump for Half-Life 2.
• interlopers.net A site that collects on tutorials for Hammer mapping as well as Texturing and other Source SDK related content.
• Halflife2.Net – Largest Half-Life 2 Community
• HLFallout – A popular Half-Life 2 fansite
• A HL2 storyline speculation by fans, dubbed "Grand Unified HL2 Theory"
• Half-Life Saga Story Guide – A speculative timeline of the Half Life games' plot as a whole.
• The Final Hours of Half-Life 2 – Gamespot's pre-release story
• Pidgeon's guide – A guide for fun console commands that can be used in Half-Life 2.