The Half-Life and Portal universe|''Half-Life'' series spawned countless '''mods''', among which many that became highly popular in the ''Half-Life'' gaming community. Some original mods, such as ''wccounterstrikeCounter-Strike|Counter-Strike'', ''http// Team Fortress'' (originally a ''Quake'' mod ported to the GoldSrc engine at Valve's request), ''WikipediaDay of Defeat|Day of Defeat'', ''WikipediaRicochet (2000 video game)|Ricochet'', ''WikipediaThe Ship (video game)|The Ship'' and ''WikipediaAlien Swarm|Alien Swarm'' (originally a mod for ''WikipediaUnreal Tournament 2004|Unreal Tournament 2004'') have been "adopted" by Valve Corporation|Valve and made into commercial games. However some mods such as ''Garry's Mod'' having been turned into commercial games remain independent. Some mods are also based on cut content, featured in the released files for ''Half-Life'', and in the Development of Half-Life 2|''Half-Life 2'' leak.

Some of these mods include minor or major alterations to the original game, others consist in a total conversion, i.e. made from scratch, only using the existing engine, models, sounds, textures, etc. The non-commercial mods can be downloaded for free, as they are not licensing the engine.

==Notable mods==


====''http// Action Half-Life''====
''Action Half-Life'' simulate action movies, especially those directed by John Woo.

====''http// Afraid of Monsters''====
''Afraid of Monsters'' is a survival horror single-player modification for ''Half-Life'', made by Team Psykskallar, the creators of Cry of Fear. It is played from the point of view of David Leatherhoff - a man addicted to drugs, experiencing fearsome illusions, and seeking help.
''Counter-Strike'' (originally marketed as ''Half-Life Counter-Strike'') is a multiplayer first-person shooter initially created by Minh Le and Jess Cliffe as a mod for ''Half-Life'' but eventually turned into a retail game developed by Valve.
====''Azure Sheep''====
{{Main|Azure Sheep}}
''Azure Sheep'' is a single-player modification for ''Half-Life'', in which the player is a member of the Black Mesa Security Force. When the chaos caused by the Resonance Cascade starts, he goes on a mission to save his colleague Kate, trapped in the complex.

====''http// Black Ops''====
In ''Black Ops'', the player slips into the role of agent Declan Walker, member of the Black Operations, a special-purpose force for covered operations, created by the government, sent on a mission to eliminate a scientist and arm the Mark IV Thermonuclear Device.
====''http// Cat-Life''====
In ''Cat-Life'' the player enters the mind and body of an oridinary house cat that finds himself in the Black Mesa facility during the Resonance Cascade.
====''Cry of Fear''====
{{Main|Cry of Fear}}
''Cry of Fear'' is a single-player, psychological horror first person shooter made by Team Psykskallar, creators of ''Afraid of Monsters''. Originally a modification of ''Half-Life'', it is now a standalone product available on Steam.

The story begins with Simon Henriksson, a 19 year old, waking up in an unknown alley shortly after being hit by a car. Much of his time is spent exploring and fighting off crazed, deformed humanoid creatures. He also receives flashbacks telling the story of what happened after the accident, varying from the police response to the resulting hospital stay.

FileCry of Fear main menu.jpg|The main menu.
FileIntro.jpg|The intro scene.
FileSimon.jpg|Simon lighting up a cigarette.
FileThe park.jpg|The Gustav Park, one of the locations visited by the main character.

====''WikipediaDay of Defeat|Day of Defeat''====
''Day of Defeat'' is a team-based, multi-player, World War II, first-person shooter computer game of the European Theater of World War II. It takes place around the year of 1944. Originally a ''Half-Life'' third party modification, it was turned into retail games developed by Valve.

====''http// Deliverance''====
''Deliverance'' is a single-player modification that continues the story of Gordon Freeman shortly after the end of ''Half-Life''.
====''Drug Barons''====
{{Main|Maverick Developments Barons}}
''Drug Barons'' is a singleplayer level pack for ''Half-Life'' by Maverick Developments. It was released in March 1999. It takes place after the events of ''Half-Life''. Gordon Freeman accepts the G-Man's offer, and joins the government department that he works for. Back on Earth, the G-Man gives Gordon a mission, and then sends him on his way. The mission is to destroy a drug factory located in a remote South American location.
====''http// Half-Life Visitors''====
''Half-Life Visitors'' is a single-player modification for ''Half-Life'', played from the point of view of Dr. Alan Green, a young lawyer, who was sent to the Black Mesa desert as a safety evaluator to carry ot a safety report of Black Mesa.
====''http// Half-Life Induction''====
''Half-Life Induction'' is a prequel to ''Half-Life'', in which the player assumes the role of Gordon Freeman.
====''http// Natural Selection''====
''Natural Selection'' is a multiplayer ''Half-Life'' modification that combines first-person combat and real-time strategy. It features "marines versus aliens" teamplay, where one marine can become a commander, who plays from a top-down perspective and leads live players, while aliens can evolve and change lifeforms to run on walls, fly or devour marines whole. On 31 October 2012, a WikipediaNatural Selection 2|standalone sequel to ''Natural Selection'' was released.
====''http// PARANOIA''====
''PARANOIA'' is a total conversion single-player modification for ''Half-Life'', player from the point of view of a Russian officer.
====''http// Peaces Like Us''====
''Peaces Like Us'' is a single-player modification, set in a world where mankind is allied to the aliens of Xen.

====''http// Point of View''====
In ''Point of View'', a single-player modification created by the author of ''Azure Sheep'', the player enters the body of a Vortigaunt|Alien Slave named Xonxt. The game starts as humans invade Xen and capture the XTBS, which is an important piece of Xen technology. The game follows this Vortigaunt's journey as it attempts to recapture the device. It features new weapons, as well as both new and old areas of Black Mesa facility and Xen.
''Redemption'' is a single-player modification  for ''Half-Life'', developed by Maverick Developments, released in October 1999, while ''Absolute Redemption'' is a retail game, released in November 2000. The mod was included in the original retail version of ''Counter-Strike''.

''Redemption'' takes place after the events in ''Half-Life''. The game assumes that Gordon Freeman accepted the G-Man's offer. Now an agent, he is given a task to retrieve three Telnorps and return them back to Xen.
====''WikipediaRicochet (2000 video game)|Ricochet''====
''Ricochet'' was originally a multiplayer mod of ''Half-Life'', but now is a retail game developed by Valve, notable for its apparent simplicity, inspired by arcade and platform games in both concept and design.  Players jump between neon-lit platforms suspended above an abyss, and shoot disks at one another, trying to push the opponent off the platform and into the depths.
====''http// Scientist Slaughterhouse''====
''Scientist Slaughterhouse'' is a single-player modification of ''Half-Life'' that allows the player to murder Black Mesa Science Team|scientists in many different ways, without any consequences.
====''Sven Co-op''====
{{Main|Sven Co-op}}
Sven Co-op is a multiplayer cooperative modification for ''Half-Life'', in which players must work together against AI-controlled enemies and solve puzzles as a team. It is one of the oldest ''Half-Life'' mods to be still in development.

FileSven screenshot.jpg|In-game screenshot.

====''Sweet Half-Life''====
{{Main|Sweet Half-Life}}
''Sweet Half-Life'' is a single-player mod for ''Half-Life'', set at a similar time to the original game and following a similar storyline. It is played through the eyes of Gordon McGinley, and follows his plight to escape from the crumbling Black Mesa Research Facility.
====''http// Team Fortress''====
''Team Fortress'' is a class- and team-based multiplayer online first-person shooter, originally released for Windows on April 1, 1999 as a mod for ''Half-Life'' but later turned intro a retail game developed by Valve.
====''http// The Ship''====
Originally a multiplayer mod for ''Half-Life'', it was later turned into a WikipediaThe Ship (video game)|retail game.
====''The Specialists''====
{{Main|The Specialists}}
''The Specialists'' is a multiplayer modification for ''Half-Life''. Originally made to be a team-play game, ''The Specialists'' evolved into a death-match game with action movie realism.
====''They Hunger''====
{{Main|They Hunger}}
''They Hunger'' is a single-player horror mod for ''Half-Life'' developed by Black Widow Games. It focuses on a small American town in the 1950s, where the player is an author that has moved to the town to get inspiration for his new book.

They Hunger church.jpg|In-game screenshot.

====''TWHL Tower''====
{{Main|TWHL Tower}}
''TWHL Tower'' is a single-player mod for ''Half-Life'', collaboratively created by members of The Whole Half-Life community.
====''USS Darkstar''====
{{Main|USS Darkstar}}
''USS Darkstar'' is a ''Half-Life'' mod created by Neil Manke and his team, largely based in Canada. The mod follows Gordon Freeman and several other scientists on board USS ''Darkstar'' in the year 2066, a large exploratory starship.

FileDsintro0000.PNG|In-game screenshot.

{{Main|Maverick Developments!}}

''Wanted!'' is a singleplayer and multiplayer total conversion for ''Half-Life'', played from the point of view of Sheriff Rogan Black.

====''http// 1187''====
''1187'', a ''Half-Life 2'' mod, takes place in Amstelveen, Netherlands during the Portal Storms.

====''http// Age of Chivalry''====
''Age of Chivalry'' is a total conversion multiplayer modification for ''Half-Life 2'' made by Team Chivalry.

====''Aperture Tag The Paint Gun Testing Initiative''====
{{Main|Aperture Tag The Paint Gun Testing Initiative}}
''Aperture Tag The Paint Gun Testing Initiative'' is a ''Portal 2'' modification based on the game ''Tag The Power of Paint''. It features the Aperture Science Paint Gun Device - a tool capable of spreading out an unlimited amount of Repulsion or Propulsion Gel - instead of the regular Portal Gun.

FileApertureTag1.jpg|The Paint Gun.
FileApertureTag4.jpg|A typical test chamber.

====''http// Awakening''====
''Awakening'' is a ''Half-Life 2'' mod that continues the story of ''Half-Life Opposing Force'', and is set before the sequel.

====''Black Mesa''====
{{Main|Black Mesa (video game)}}
''Black Mesa'' is both a third-party total conversion mod for ''Half-Life 2'' and remake of the original ''Half-Life''. The ultimate goal of the mod is to recreate the original ''Half-Life'' from the ground up, using the advanced capabilities of the Source|Source engine to create a new and more engrossing in-game world with more varied, complex environments and more challenging, realistic gameplay.

File0003-c0a0 release12001.jpg|Pre-release in-game screenshot.
File0007-c1a0 release11001.jpg|Ditto.
FileBMS Tau beauty.jpg|The Tau Cannon concept art.
FileAGrunt Frnt2.jpg|The Alien Grunt pre-release render.

====''Black Mesa Uplink''====
{{Main|Black Mesa Uplink}}
''Black Mesa Uplink'' is a third-party remake of the original ''Half-Life Uplink'', one of the demo versions of Half-Life.

====''The Citizen''====
{{Main|The Citizen}}
''The Citizen'' is a series of single-player mods for ''Half-Life 2'', set in a storyline parallel to the original game. The player takes the role of an ordinary man, pushed over the edge by the oppressive regime controlling his life. His home trashed, his family dead, The Citizen leaves his apartment for the last time. He seeks new friends, and a way to help the human resistance to smash the iron grip of the Combine. What follows is a winding tale of betrayal, determination and grief. Many obstacles lie in his path which require a sleek combination of agility, stealth, intelligence, and sheer violence to overcome.

====''http// Coastline to Atmosphere''====
''Coastline to Atmosphere'' is a single-player mod for ''Half-Life 2'', released in 2006, that continues the story of the game.

====''Combine Destiny''====
{{Main|Combine Destiny}}
''Combine Destiny'' is a ''Half-Life 2'' mod played from the point of view of a Combine Soldier.

====''http// DayHard''====
''DayHard'' is a single-player ''Half-Life 2'' mod, set before the events of that game, in which the player assumes the role of Gordon's brother - Morgan Freeman.

====''WikipediaDear Esther|Dear Esther''====
''Dear Esther'' is a first person art video game, released in June 2008 as a free Source mod, and later redeveloped for a commercial release in February 2012. The game does not follow traditional video game conventions, as it involves minimal interaction from the player and does not require choices to be made nor tasks to be completed. It instead places focus on its story, which is told through a fragmented, epistolary narrative as the player explores an unnamed island in the Hebrides.

====''WikipediaDino D-Day|Dino D-Day''====
''Dino D-Day'' is a multiplayer team-based total conversion modification on the Source engine, in which the players can battle online choosing to serve either the Allied nations or the Nazis, with both sides aided by resurrected dinosaurs.

====''http// D.I.P.R.I.P.''====
''D.I.P.R.I.P.'' is a ''Half-Life 2'' multiplayer total conversion modification, based on vehicle combat and set in various post-war environments.

''Dystopia'' is a multiplayer cyberpunk-themed mod for ''Half-Life 2''. 

Dystopia 2.jpg|In-game screenshot.

====''FakeFactory's Cinematic Mod''====
{{Main|FakeFactory's Cinematic Mod}}
''FakeFactory's Cinematic Mod'' is a modification that aims to improve ''Half-Life 2'' and its episodes, and push the Source engine capabilities as far as possible.

FileFakefactor Alyx V8.jpg|HD Alyx based on Brazilian model WikipediaAdriana Lima|Adriana Lima in ''Version 8'' of ''FakeFactory's Cinematic Mod''.
FileCinematic mod 10 superportal.jpg|Comparison of the original and the updated destroyed City 17 in ''Version 10''.
FileCinematic mod 10 nexus.jpg|The Overwatch Nexus in ''Version 10''.

====''Garry's Mod''====
{{Main|Garry's Mod}}
''Garry's Mod'' is a sandbox modification for ''Half-Life 2''. It allows the player to manipulate objects and experiment with the physics of the Source engine, often with interesting results due to the power of the engine. Being a sandbox type game there is no goal as such or a way to win, rather users are able to modify the game and play the mod however they wish. Many different gamemodes have emerged with many different objectives and styles. Some even choose to remain in the sandbox mode to construct contraptions or scenery with the props and maps from most of Valve's games. 

The current version of ''Garry's Mod'' is version 13, which still receives regular updates via Steam Valve no longer categorizes ''Garry's Mod 13'' as a modification, but rather as a full game, due to its ubiquity and popularity.

FileGmod late 2009.jpg|The ''Garry's Mod'' menu introduced in late 2009.

====''http// Eternal Silence''====
''Eternal Silence'' is a cinematic multiplayer Source engine modification that takes place in the outer space.

====''http// GoldenEye Source''====
''GoldenEye Source'' is a total conversion modification of ''Half-Life 2'', and a remastered verison of the original GoldenEye64.

====''http// Guard Duty''====
''Guard Duty'' is an upcoming remake of ''Half-Life Blue Shift'' on the Source engine.

====''http// Half-Life 2 Capture the Flag''====
''Half-Life 2 Capture the Flag'' is a multiplayer modification of ''Half-Life 2'' that centers around the title game mode.

====''http// Half-Life 2 Riot Act''====
''Half-Life 2 Riot Act'' is a single-player modification for ''Half-Life 2''. It is played from the point of view of Jamil Lee, a young member of the civilian Resistance, taken by the Combine and currently imprisoned in Nova Prospekt.

====''http// Half-Life 2 Short Stories Human Error''====
''Half-Life 2 Short Stories Human Error'' is a ''Half-Life 2 Episode One'' modification, in which the player takes the role of a Civil Protection officer called Anders.

====''Lambda Wars''====
{{Main|Lambda Wars}}
''Lambda Wars'', previously known as ''Half-Life 2 Wars'', is a multiplayer Source engine modification that brings the war between mankind and the Combine to a real-time strategy setting.

''MINERVA'' is an episodic single-player modification for ''Half-Life 2'' created by Adam Foster and is a follow-up to his previous mod for ''Half-Life'', ''Someplace Else''.

====''Missing Information''====
{{Main|Missing Information}}
''Missing Information'', is a single-player modification based on the cut content from the Development of Half-Life 2 game|''Half-Life 2'' leak.

====''Mistake of Pythagoras''====
{{Main|Mistake of Pythagoras}}
''Mistake of Pythagoras'' is a single-player modification for ''Half-Life 2'', developed by the creator of ''Sweet Half-Life''. The player takes the role of Gordon Freeman in a parallel world.

====''WikipediaNuclear Dawn|Nuclear Dawn''====
''Nuclear Dawn''  is a post-apocalyptic first-person shooter real-time strategy hybrid video game, originally announced in February 2006 as an amateur mod for the Source engine, but in April 2009 was revealed to have become a commercial project, still using Source. It was released on September 26, 2011.

====''Obsidian Conflict''====
{{Main|Obsidian Conflict}}
''Obsidian Conflict'' is a community-based cooperative mod for ''Half-Life 2'' and its episodes.

====''Operation Black Mesa''====
{{Main|Operation Black Mesa}}
''Operation Black Mesa'' is an upcoming modification for ''Half-Life 2'' and a complete Source conversion of ''Half-Life Opposing Force''.

====''Portal Prelude''====
{{Main|Portal Prelude}}
''Portal Prelude'' is a modification for ''Portal'' which aims to extend the ''Portal'' storyline.

====''Portal Stories Mel''====
{{Main|Portal Stories Mel}}

Explores the story of Mel, protagonist cut from ''Portal 2''.

====''Portal The Flash Version MapPack''====
{{Main|Portal The Flash Version MapPack}}
''Portal The Flash Version MapPack'' is a fan-made mappack for ''Portal''. It is based on the online Flash game ''Portal The Flash Version'', developed by the same team.

====''http// Research and Development''====
''Research and Development'' is a puzzle-centric single-player mod for ''Half-Life 2 Episode Two''.

''SMOD'' is single-player modification which adds new effects, weapons, and NPCs to ''Half-Life 2''.

====''http// SourceForts''====
''SourceForts'' is a ''Half Life 2 Deathmatch'' team-based mod, in which player build bases and other structures with props in a "build phase", and then fight and try to capture the enemy's flag in a "combat phase".

''Synergy'' is a co-operative multiplayer modification for ''Half-Life 2'', ''Half-Life 2 Lost Coast|Lost Coast'', ''Half-Life 2 Episode One|Episode One'', ''Half-Life 2 Episode Two|Episode Two'', and ''SiN Episodes Emergence''. It also includes fan-made cooperative maps, as well as support for the mods ''MINERVA'', ''Half-Life 2 Riot Act'' and ''City 7 Toronto Conflict''. It is available for download on WikipediaSteam (software)|Steam. 

====''Thinking with Time Machine''====
{{Main|Thinking with Time Machine}}
''Thinking with Time Machine'' is a ''Portal 2'' modification that introduces new time-based mechanics in addition to the standard Portal Gun.

====''Weekday Warrior''====
{{Main|Weekday Warrior}}
''Weekday Warrior'' is a mod for ''Half-Life 2''. Set inside a modern corporate office environment, the player takes on the persona of Doug Smith, a very bored man with the untapped potential for greatness.

====''http// Zombie Master''====
''Zombie Master'' is a multiplayer ''Half-Life 2'' modification, centred around a zombie-apocalypse, which throws all but one player in the shoes of human survivors.

====''Zombie Panic! Source''====
{{Main|Zombie Panic! Source}}
''Zombie Panic! Source'' is a multiplayer ''Half-Life 2'' modification that pays homage to the popular Zombie genre of movies and games.

==External links==

*http// The Valve Developer Community - official knowledge base for developers
*http// Mod DB - Mod database
*http// Planet Phillip - mods for both GoldSrc and Source engines, and some sneak peeks on unreleased mods
*http// - ''Half-Life 2'' News & Tutorials
*http// ''Half-Life'' Downloads on FilePlanet
*http// ''Half-Life 2'' mods
*http// FPSBANANA - The FPS Customization Community

CategoryThird-party games
CategoryNon-canon games
CategoryFan content