The series' logo, an orange lambda, is a prominent symbol throughout the series
|Platform of origin||Windows|
November 19, 1998
|Latest release||Half-Life 2: Episode Two
October 10, 2007
Half-Life (stylized HλLF-LIFE) is a series of first-person shooter video games that share a single science fiction alternate history. The games in the series all utilize either the GoldSrc or Source engines and are linear, narrative, single-player titles.
Valve Corporation is the developer, and partly the publisher and distributor, for their signature games of the series. The major titles in the series feature the player as the protagonist, Gordon Freeman, a theoretical physicist initially employed by the Black Mesa Research Facility. Two of these games, Half-Life and Half-Life 2 are full length titles, while two more, Half-Life 2: Episode One and Half-Life 2: Episode Two, are shorter, episodic titles. A final episode, Half-Life 2: Episode Three, was originally scheduled to appear around Christmas 2007, but now has no public release date.
The Half-Life series begins sometime in the 2000s, at the fictional Black Mesa Research Facility in New Mexico. Gordon Freeman, a recently employed theoretical physicist, is involved in an experiment analyzing an unknown crystalline artifact; however, when the beam of the anti-mass spectrometer contacts the crystal, it creates a resonance cascade that opens a dimensional rift between Black Mesa and a trans-dimensional world called Xen, causing extraterrestrial lifeforms to swarm Black Mesa and kill many of the facility's personnel. Attempts by the Black Mesa personnel to close the rift are unsuccessful, leading to a Marine Recon unit being sent in to silence the facility, including any survivors from the science team. Freeman fights through the facility to meet with several other scientists, who decide to travel to the alien dimension to stop the aliens. On Xen, Freeman eliminates the alien "leader", the Nihilanth, and is confronted by the G-Man, who offers Freeman an employment opportunity, before putting him into stasis. Back in Black Mesa, a second alien race begins an invasion, but is stopped when a Marine corporal, Adrian Shephard, collapses the portal in the facility. The G-Man then destroys Black Mesa with a nuclear warhead, and detains Shephard in stasis. Barney Calhoun, a security officer, also escapes from the facility with Dr. Rosenberg and two other scientists.
Nearly twenty years later, Half-Life 2 opens as the G-Man brings Freeman out of stasis and inserts him into a dystopian Earth ruled by the Combine, a faction consisting of human and alien members that used the dimensional rift that was caused at Black Mesa, to conquer Earth in the interim. In City 17, an eastern European settlement, Freeman meets surviving members of the Black Mesa incident, including Isaac Kleiner, Barney Calhoun, Eli Vance and his daughter Alyx Vance, and aids in the human resistance against Combine rule. The Xen aliens, the Vortigaunts, who have been enslaved by the Combine, also assist the resistance. When his presence is made known to former Black Mesa administrator and Combine spokesman Wallace Breen, Freeman becomes a prime target for the Combine forces. Eventually, Freeman sparks a full revolution amongst the human citizens after destroying Nova Prospekt, a major Combine base and troop-production facility. Eli Vance and his daughter are subsequently captured by the Combine, and Freeman helps the resistance forces attack the Combine's Citadel to rescue them, fighting alongside Barney. Freeman fights his way through the Citadel, making his way to Breen's office. He is temporarily captured, but freed by Dr. Mossman, along with Eli and Alyx. Breen attempts to flee in a teleporter, but is presumed dead after Freeman destroys the dark energy reactor at the Citadel's top.
The story continues with Half-Life 2: Episode One, as the G-Man then arrives to extract Freeman before he is engulfed in the explosion, but is interrupted when Vortigaunts liberate Freeman from stasis and place both him and Alyx Vance at the bottom of the Citadel. Alyx then contacts her father, Eli Vance, and Isaac Kleiner, who have escaped the city into the surrounding countryside. Kleiner informs them that the reactor's core has gone critical due to the destruction of the dark energy reaction, and is at risk of exploding at any moment, an explosion which could completely destroy City 17. To delay the explosion they must enter the Citadel's now-decaying core and attempt to stabilize its primary reactor while the citizens evacuate the city from a train station. While inside, they discover that the Combine are attempting to speed up the destruction of the reactor, and use the destruction of the Citadel to call for reinforcements from the Combine's native dimension. After downloading critical data, they move through the war-torn city to the train station to take the last train out of the city. The Combine then destroy the reactor and thus both the Citadel and the city; the resulting explosion causes the train to derail.
Half-Life 2: Episode Two begins as Freeman awakens in one of the wrecked train cars with Alyx outside. In the distance a forming superportal is visible where the Citadel used to stand. They begin a journey through the White Forest to a resistance-controlled missile base in the nearby mountains. Along the way, Freeman and Alyx are ambushed and Alyx is severely injured. However, a group of Vortigaunts are able to heal her. During the healing ritual, Freeman receives word from G-Man, indicating that the Vortigaunts were keeping him at bay. G-Man demands that Freeman take Alyx to White Forest as safely as possible, saying that he cannot help as per restrictions he has agreed to. They are able to reach the resistance base and deliver the data, which contains the codes to destroy the portal as well as information on the Borealis, an enigmatic research vessel operated by Black Mesa's rival, Aperture Science; however, the ship disappeared while testing portal technology. The base then launches a satellite that is able to shut down the superportal, cutting off the Combine from outside assistance. However, as Alyx and Freeman prepare to travel to the Arctic and investigate the Borealis, they are attacked by Combine Advisors, who kill Eli Vance, before being driven off by Alyx's pet robot, D0g. The game ends with Alyx crying over her father's dead body, as the screen fades to black.
|1999||Half-Life: Opposing Force|
|2001||Half-Life: Blue Shift|
|Half-Life 2: Deathmatch|
|2005||Half-Life 2: Lost Coast|
|2006||Half-Life 2: Episode One|
|2007||Half-Life 2: Episode Two|
The Half-Life series includes a core set of titles which carry the main storyline. These games were released in chronological order, either portraying the events of one game from the perspective of a different character, or following on from the events that are depicted in the previous title. As of May 2010, the main series consists of the original video game and its sequel, as well as three expansion packs and two episodic games. A third episodic game remains in development. In addition, several spin-off titles have been released. These vary in nature, consisting of an arcade game, technology demonstration, and a series of puzzle games. The original game and its expansions all use Valve's GoldSrc game engine, a heavily modified Quake engine. The later games accompanying the sequel all use Valve's proprietary Source engine.
Half-Life is the first game in the series, and was the debut title of Valve Software. First released on November 19, 1998, Half-Life follows Gordon Freeman, a theoretical physicist, after the Black Mesa Research Facility accidentally causes a dimensional rift which allows the facility to be invaded by aliens. Freeman consequently attempts to survive the slaughter and resolve the situation. The game was originally published by Sierra Studios and released for Windows, although Gearbox Software would later port the game to PlayStation 2 in 2001. Valve themselves later converted the game to use their Source engine. Half-Life received critical acclaim upon release, critics hailing its overall presentation and numerous scripted sequences. The game won over 50 Game of the Year awards and its gameplay has influenced first-person shooters for years to come. Half-Life has since been regarded as one of the greatest games of all time.
Half-Life was followed by an expansion pack, Half-Life: Opposing Force, on November 1, 1999. Unlike Half-Life, Opposing Force was developed by Gearbox Software, although it was still published by Sierra Studios. Opposing Force was first announced as a mission pack for Half-Life in April 1999, and was released for the Windows version of the game. The player no longer assumes the role of Gordon Freeman, but rather sees the later events of the first game from the perspective of a US Marine corporal, Adrian Shephard. Shephard is initially assigned to cover up the events at Black Mesa, but is soon left isolated and has to fight to survive against a new group of alien invaders and black operations units. Opposing Force was received favorably by critics, many citing the game as being as influential on setting expansion pack standards as the original game had been in influencing the overall genre. The game won the Computer Game of the Year Interactive Achievement Award of 2000 from the Academy of Interactive Arts & Sciences.
Gearbox later went on to develop Half-Life: Blue Shift, Half-Life's second expansion pack. Like Opposing Force, Blue Shift was published by Sierra Entertainment. Announced in 2000, the game was initially developed as an add-on for a Dreamcast port of Half-Life; however, the port was cancelled and Blue Shift was instead released for Windows on June 12, 2001. Blue Shift puts the player in the position of Barney Calhoun, a security guard working at Black Mesa. The game takes place within the early parts of Half-Life, with Calhoun attempting to escape the facility with a small group of scientists. Blue Shift also includes a High Definition pack, which upgrades the quality of the models and textures in both Blue Shift and the preceding games in the series. Critics gave Blue Shift a mixed but favorable reception, praising the game's atmosphere and the inclusion of the High Definition pack, but criticizing the otherwise lack of new content and short length of the story.
The third and final expansion for Half-Life was Half-Life: Decay. The game was again developed by Gearbox and published by Sierra. However, unlike previous titles, Decay is only available with the PlayStation 2 version of Half-Life. Decay is unique within the Half-Life series as the only cooperative game—two players must work together to progress through the game. Decay focuses on two of Freeman's colleagues, Gina Cross and Colette Green, as the two work with other scientists to counter the effects of the dimensional rift and ultimately attempt to close it. Released on November 14, 2001, Decay received a weak but overall positive reception from critics, many reviewers stating that it was fun to play through with a friend, but that the game's more puzzle-oriented gameplay detracted from the overall experience. An unofficial Windows port of the game was released in September 2008.
On November 16, 2004, Valve released Half-Life 2, the sequel to the original game. The game had a six-year development cycle, which saw several delays and the leak of the game's source code. Half-Life 2 returns the player to the role of Gordon Freeman. Set twenty years after the original game, Earth has been occupied by the Combine, a transdimensional race that exploited the events of the first game to invade. The G-Man inserts Freeman into City 17 in Eastern Europe to combat the Combine occupation. Half-Life 2 garnered near-unanimous positive reviews and received critical acclaim much like its predecessor, winning over 35 Game of the Year awards for 2004. Considered one of the greatest video games of all time, the game has been critically praised for its advances in computer animation, sound, narration, computer graphics, artificial intelligence, and physics. Half-Life 2 was the first title to use Valve's Steam content delivery system, a system that eventually led to Valve falling out with publisher Sierra Entertainment.
Following Half-Life 2, the series was continued using a pair of episodic games, with a third planned. Half-Life 2: Episode One was the first of these, set around City 17 after the events of the original game, in which Freeman and Alyx Vance must attempt to escape the city after a dark energy reactor core they damaged at the end of Half-Life 2 threatens to destroy the city. It was released on June 1, 2006, and introduced several new graphical effects including new lighting features and more advanced facial animation. Episode One received a generally positive critical reaction, although the game's short length was a point of common criticism.
The second episodic game, Half-Life 2: Episode Two, continues the story from where Episode One ended. It was released on October 10, 2007, bundled with the games Portal and Team Fortress 2 as well as Half-Life 2 and Episode One in the package The Orange Box, which was released for Windows PCs and the Xbox 360 and PlayStation 3 consoles. The game was again developed by Valve, and distributed using both Steam and Electronic Arts. Continuing with Valve's policy of orienting each episode around a particular theme or set of technologies, Episode Two focuses on expansive environments, travel and less linear play. As Gordon Freeman, the player travels with Alyx Vance away from the ruins of City 17 into the surrounding countryside, pursued by Combine forces. Episode Two's new technologies and gameplay features were praised by reviewers; however, though it was significantly longer than Episode 1, the short length of the game was again a point of criticism.
Half-Life 2: Episode Three is announced as the third and final installment in the series of episodic expansions. It is planned as the last episode in the story arc, but Valve has stated it will not be the end of the entire Half-Life franchise. Some concept art has surfaced as well as the possible incorporation of sign language into the game by including a deaf character. In a March 2010 interview, Newell spoke of "broadening the emotional palette" of the series, and how the next Half-Life game may return to "genuinely scaring the player". In a May 9, 2011, interview with Develop magazine, Newell commented on the episodic release model, saying, "We went through the episodes phase, and now we’re going towards shorter and even shorter cycles," adding, "For me, ‘entertainment as a service’ is a clear distillation of the episodic content model." Due to the large number of delays in its production to the point where Valve employees have refused to comment on the release, Episode Three has become one of video gaming's most infamous cases of vaporware.
Return to Ravenholm, sometimes referred to as Half-Life 2: Episode Four, was being developed by Arkane Studios before being cancelled. The episode would have featured the town of Ravenholm and involved headcrabs and zombies, but due to taking place before the end of Half-Life 2: Episode Two, Valve felt it would be constrained creatively.
Another abandoned episode was being developed by Junction Point Studios, and would have featured a magnet gun. However, Warren Spector stated that the studio's direction shifted to working on Disney's Epic Mickey, and the project was dropped.
The Portal series, which takes place in the same universe as the Half-Life games, is a series of puzzle games developed by Valve Corporation. The first game in the series, Portal, was initially released alongside Episode Two in The Orange Box on October 10, 2007. The player controls a test subject named Chell as she moves through the laboratories of Black Mesa's primary rival, Aperture Science, completing various tests with a device that allows her to create linked portals in physical space. In the later stages of the game, the player battles GLaDOS, a corrupt artificial intelligence computer that monitors her every move. The game is the spiritual successor to Narbacular Drop, with many of the same team members working on the game. Portal has been acclaimed as one of the most original games in 2007, receiving praise for its unique gameplay and darkly humorous story. An Xbox Live Arcade expansion was released on October 22, 2008, and its sequel, Portal 2, was released on April 19, 2011.
Half-Life 2: Lost Coast
Half-Life 2: Lost Coast is a technology demonstration, developed by Valve to display new high dynamic range rendering and a variety of other features. Valve asked for feedback as to whether these features should be used in their future games. The level was designed with a variety of appropriate environments to emphasize these effects. Consisting of a single map, Lost Coast was originally to be part of Half-Life 2, but was dropped during development. The game follows Gordon Freeman as he travels up a coastal cliff to destroy a Combine artillery launcher in a monastery, which is firing on the town of St. Olga. Released over Steam on October 27, 2005, the level received a generally positive reception, and there was consensus among fans that the new features should be implemented into future games released by Valve.
The success of the Half-Life series has spurred the creation of several spin-off games for Half-Life 2. Codename: Gordon is a two-dimensional Flash sidescroller shooter produced by Nuclearvision Entertainment, and was released over Valve's Steam online delivery system on May 16, 2004, as a promotional game for the then-upcoming Half-Life 2. The developer has since gone bankrupt, but the game itself can still be installed via a direct link to Steam, despite not being listed in the store. Codename: Gordon was well received by reviewers and the public, and attracted over 600,000 players in the first three weeks after its release. Reviewers praised the game for its gameplay and unique dialog style, but also criticized it for its improper optimization, and lack of opponent variety.
Characters from Half-Life have appeared in other titles. Peggle Extreme, a special edition of Peggle bundled with the PC version of The Orange Box features levels based on Half-Life 2, Team Fortress 2 and Portal. The headcrab is also an unlockable character in Super Meat Boy when bought on Steam. The Headcrab also appeared in an April Fools event in the MMO Vindictus as an event item along with the Crowbar, possibly due to the game being created on the Source Engine as well. In the game Magicka there is a playable character (after the addition of a DLC), which closely resembles the original zombie from the Half-Life universe, equipped with a crowbar. Gordon also appears in Renegade Ops and the headcrab is available as a pet in Torchlight 2.
The video game development company behind the Half-Life series, Valve Corporation, was founded in 1996 in Kirkland, Washington by former Microsoft employees Mike Harrington and Gabe Newell. Valve began working on the first game of the series soon after the company's formation, and settled on a concept for a horror-themed 3D action game, using the Quake engine as licensed by id Software. The game was a hit at the 1997 E3 convention, where its animation system and artificial intelligence were demonstrated. The game's success led to its first expansion pack, Half-Life: Opposing Force, which was developed by Gearbox Software, a then-new company based in Plano, Texas, and announced on April 15, 1999. Gearbox founder Randy Pitchford said in an interview that he believed Valve gave them the opportunity to produce a sequel to Half-Life to allow Valve to focus on future titles. The game was demonstrated at the 1999 E3 convention, where new locations, characters, and the story were revealed.
The second Half-Life expansion pack, Half-Life: Blue Shift, was again developed by Gearbox Software and announced by its publisher, Sierra Entertainment, on August 30, 2000. Sierra intended to release Blue Shift for the Dreamcast, and it was set to include higher detail models and textures that were double the polygon count of the models from Half-Life. However, after several months of delays, Sierra terminated development on the Dreamcast version of Blue Shift on June 16, 2001, and the company instead released Blue Shift for the PC on June 12, 2001. Afterward, Gearbox began working on a Half-Life game for the PlayStation 2. The game, titled Decay, was showcased at E3 2001, where Gearbox demonstrated the game's use of new model sets, which were around twice as detailed as those in Blue Shift.
For several years, Valve secretly worked on the sequel to the original Half-Life, titled Half-Life 2. For the game, Valve 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. In the trilogy of episodic games that followed Half-Life 2, Valve made minor tweaks to the game's engine. In Half-Life 2: Episode One, Valve modified Alyx's AI to allow her to react to the player's actions because of her significant involvement in the game. The game runs on an upgraded version of Valve's proprietary Source engine, and features both the engine's advanced lighting effects, and a new version of its facial animation/expression technology.
On February 6, 2013, while speaking at the 2013 DICE conference about storytelling in games and film, J. J. Abrams and Gabe Newell announced that they had plans for a game and a film collaboration. Abrams said, "There's an idea we have for a game that we'd like to work with Valve on," while Newell said, "We're going to figure out if we can make a Portal movie or Half-Life movie together". In an interview in March 2016, Abrams stated that while he has been working on many other projects since, he still has plans to direct these films in the future, with both films in the writing stage.
Cultural influence and reception
A short film based upon Half-Life, titled Half-Life: Uplink, was developed by Cruise Control, a British marketing agency, and released on March 15, 1999. However, Sierra withdrew it from circulation after Sierra and Valve had failed to resolve licensing issues with Cruise Control over the film. The critical reception of the film was very poor. The film's plot was that of a journalist attempting to infiltrate the Black Mesa Research Facility and discover what was happening there.
In early 2009, the Purchase Brothers, a Toronto-based film company, released a five-minute film based on Half-Life 2: Episode One called Half-Life: Escape from City-17. The film combines live-action footage with 3D animation created using the Source SDK for the video game. It was well received by Valve. On August 25, 2010 they released a nearly 15 minute long part two. In late 2010 a trailer for a Half-Life inspired independent short film entitled Beyond Black Mesa was released. Directed by Brian Curtin, it follows the character Adrian Shephard. The full short film was released online on January 21, 2011.
- "Half-Life 2: Episode One gold, Two dated, Three announced". GameSpot. 2006-05-24. Retrieved 2007-05-18.
- "Half-Life: The Story so Far". Valve Corporation. Retrieved 2008-03-24.
- "Half-Life". IGN. Retrieved 2008-10-23.
- "Half-Life: Source for PC". GameSpot. Archived from the original on May 22, 2007. Retrieved 2009-05-26.
- "Half-Life Reviews (PC: 1998)". Metacritic. Retrieved 2009-05-26.
- "Awards and Honors". Valve Corporation. Retrieved 2005-11-14.
- Cifaldi, Frank (2006-09-01). "The Gamasutra Quantum Leap Awards: First-Person Shooters". Gamasutra. Retrieved 2009-02-16.
- "IGN's Top 100 Games". IGN. 2005-07-25. Retrieved 2009-02-19.
- "Half-Life: Opposing Force". Steam. Valve Corporation. Retrieved 2008-11-19.
- "Half-Life Expands". IGN. 1999-04-15. Retrieved 2008-11-18.
- "Half-Life: Opposing Force Reviews". GameRankings. Retrieved 2008-11-18.
- Wolpaw, Erik (1999-11-24). "Half-Life: Opposing Force for PC Review". GameSpot. Retrieved 2008-11-20.
- Randell, Kim (2001-08-15). "PC Review: Half-Life: Opposing Force". Computer and Video Games. Retrieved 2008-11-20.
- "Review: Half-Life: Opposing Force". GamePro. 2000-11-24. Archived from the original on 2008-12-29. Retrieved 2008-11-20.
- "AIAS Annual Awards: 3rd Annual Awards". Academy of Interactive Arts & Sciences. 2000. Archived from the original on February 20, 2009. Retrieved 2008-11-21.
- Kirchgasler, Chris (2000-07-24). "Half-Life Preview". GameSpot. Retrieved 2016-03-31.
- Satterfield, Shane (2001-06-16). "Half-Life for the Dreamcast officially cancelled". GameSpot. Retrieved 2008-10-26.
- "Half-Life: Blue Shift". IGN. Retrieved 2008-10-26.
- "Half-Life: Blue Shift Q&A". GameSpot. 2001-05-03. Retrieved 2008-10-26.
- "'Half-Life: Blue Shift (PC: 2001): Reviews". Metacritic. Retrieved 2008-10-27.
- Blevins, Tal (2001-06-12). "Half-Life: Blue Shift Review". IGN. Retrieved 2008-10-27.
- Madigan, Jamie. "Reviews: Half-Life: Blue Shift". GameSpy. Retrieved 2008-10-27.
- Kasavin, Greg (2001-06-08). "Half-Life: Blue Shift for PC Review". GameSpot. Retrieved 2008-10-27.
- "Half-Life". IGN. Retrieved 2008-10-23.
- Fielder, Joe (2001-05-17). "E3 2001 Hands-on Half-Life". GameSpot. Retrieved 2008-10-23.
- Hodgson, David. "Reviews: Half-Life (PS2)". GameSpy. Retrieved 2008-10-23.
- Smith, Steve. "Review: Half-Life". The Electric Playground. Retrieved 2008-10-24.
- Radcliffe, Doug (2001-10-15). "Half-Life for PlayStation 2 Review". GameSpot. Retrieved 2008-10-23.
- Meer, Alec (2008-09-28). "Half-Life: The Lost Chapter". Rock, Paper, Shotgun. Retrieved 2008-10-24.
- Hilderbrand, Brad. "Half-Life 2: Episode 3 to Debut at E3 (Update)". TheGameReviews. Archived from the original on June 30, 2008. Retrieved 2008-08-09.
- Ted Backman; Jeremy Bennett; Tristan Reidford (2008-07-09). "Advisor". Into the Pixel. Retrieved 2008-07-14.
- Decker, Logan (2008-07-10). "The first concept art from Half-Life 2: Episode Three". PC Gamer. Retrieved 2008-07-14.
- Chris_D (2012-06-27). "EXCLUSIVE: Half-Life 2: Episode 3 Concept Art". ValveTime. Retrieved 2013-07-29.
- McWhertor, Michael (2009-08-07). "Valve Studying Sign Language For Deaf Half-Life Character". Kotaku. Retrieved 2009-08-23.
- Yoon, Andrew (August 7, 2009). "Valve researching sign language for use in Half-Life 2: Episode 3". engadget. Retrieved March 31, 2009.
- Reilly, Jim (August 10, 2009). "Valve Studying Sign Language for Episode 3?". IGN. Retrieved March 31, 2016.
- Brian Warmoth (March 26, 2010). "Valve Wants Their Next 'Half-Life' To Scare You". Retrieved 2010-03-28.
- Rob Crossley (9 May 2011). "The Valve manifesto".
- Hess, Bill (15 March 2013). "Half Life 3 questions appear to be getting old for Gabe Newell". Retrieved 30 September 2013.
- Calore, Michael (3 January 2011). "Vaporware 2010: The Great White Duke". Wired.com. Retrieved 30 July 2013.
- "Marc Laidlaw On The Cancelled Half-Life Spin-offs: Return To Ravenholm And "Episode Four"". LambdaGeneration. 13 January 2012. Archived from the original on 16 January 2012. Retrieved 19 July 2013.
- Savage, Phil (15 January 2013). "Half-Life 2: Episode 4 was being developed by Arkane; now cancelled". PC Gamer. Retrieved 8 July 2014.
- Turi, Tim (24 April 2015). "Abandoned Half-Life Episode Featured Magnet Gun, Warren Spector Says". Retrieved 19 May 2015.
- "Codename: Gordon: Game Highlights". IGN. Retrieved March 31, 2016.
- "Codename Gordon". Steam Database. Retrieved March 31, 2016.
- Doomer, Ivan. "Free Steam games list". Steam User's Forums. Archived from the original on May 17, 2009. Retrieved 2009-10-01.
- Keighley, Geoffrey. "The Final Hours of Half-Life". GameSpot. Archived from the original on January 16, 1999. Retrieved 2008-12-17.
- "Half-Life Expands". IGN. 1999-04-15. Retrieved 2008-12-17.
- "Half-Life: Opposing Force interview". Computer and Video Games. 2001-08-15. Retrieved 2008-12-17.
- "Half-Life: Opposing Force". IGN. 1999-05-25. Retrieved 2008-12-18.
- Trueman, Doug (2000-08-29). "DC Half-Life Includes Blue Shift". GameSpot. Retrieved 2008-12-18.
- Stahl, Ben (2000-09-05). "ECTS Half-Life Dreamcast Hands-On". GameSpot. Retrieved 2008-10-26.
- "ECTS 2000: Hands-On With Half-Life". IGN. 2000-08-01. Retrieved 2008-10-26.
- "Half-Life Preview". IGN. 2001-09-19. Retrieved 2008-10-23.
- Ajami, Amer (2001-09-11). "Half-Life Updated preview". GameSpot. Retrieved 2008-10-23.
- Fudge, James (2004-03-25). "Havok's Half-Life 2 Marketing Campaign". GameSpy. Retrieved 2008-09-23.
- Half-Life 2: Episode One, Chapter V: Exit 17, Developers commentary (DVD). 2006.
- Bramwell, Tom (2006-06-06). "Opening the Valve". Eurogamer. Retrieved 2007-04-29.
- "Valve working with J.J. Abrams' Bad Robot on game and movie collaborations".
- "Portal, the Movie: Valve, J.J. Abrams Team Up for Future Games, Films".
- Strom, Steven (2016-03-12). "J.J. ABRAMS: PORTAL, HALF-LIFE MOVIES STILL HAPPENING". IGN. Retrieved 2016-03-12.
- "Half-Life: Uplink Movie". Blue's News. 1999-02-17. Retrieved 2006-12-16.
- "Half-Life: Uplink — Page 1". Planet Half-Life. 1999-03-15. Retrieved 2006-12-16.
- "Editors Note: Uplink Movie". Planet Half-Life. 1999-03-15. Retrieved 2006-12-16.
- Brown, Michael (1999-02-17). "Half-Life: The Movie". CNET. Archived from the original on 2000-05-31. Retrieved 2006-12-16.
- Walker, John (2009-02-13). "Escape From City 17: Part One". Rock, Paper Shotgun. Retrieved 2009-02-17.
- "Escape From City 17: Part One". Valve Corporation. 2009-02-13. Retrieved 2010-05-15.
- Wallace, Lewis (11 November 2010). "Trailer: Indie Sci-Fi Short Beyond Black Mesa Channels Half-Life". Wired. Condé Nast Publications. Retrieved 17 November 2010.