{{short description|Series of video game engines}} {{Other uses|Id tech (disambiguation)}} {{lowercase title}} [[File:Quake - family tree 2.svg|thumb|''Quake'' family tree, showing engines and a selection of games based on the ''Quake'' engine]] '''id Tech''' is a series of successive game engines designed and developed by id Software. They are used in many of id Software's games, such as games in the ''Doom'', ''Quake'' and ''Wolfenstein'' franchises, and has been also licensed to other developers. Several notable game engines, such as GoldSrc or the IW engine originate from id Tech code.
Earlier game engines up to id Tech 4 have been released as free software under the GNU General Public License (GPL-2.0-or-later until 2005, GPL-3.0-or-later until 2012). id Tech 5 to 8 remain proprietary, with id Tech 8 currently being the latest engine.
According to ''Eurogamer.net'', "id Software has been synonymous with PC game engines since the concept of a detached game engine was first popularised." However, id Tech 4 had far fewer licensees than Unreal Engine from Epic Games. id planned to regain the momentum with id Tech 5,<ref name="www.eurogamer.net">{{cite web|url=http://www.eurogamer.net/articles/id-tech-5-interview|title=id Tech 5 - Steve Nix on the growth of id's next engine|last=Bramwell|first=Tom|publisher=Eurogamer|date=2007-09-08|access-date=2017-05-15}}</ref> until the company was bought by ZeniMax Media in 2009 (who was later bought by Microsoft in 2021), with both companies choosing to keep the id Tech engines exclusively for id and its sister studios as a proprietary engine.
== Naming == Prior to the reveal of id Tech 5 at WWDC 2007,<ref>{{Cite web |date=2007-06-11 |title=EA and id Renew Mac Support, Carmack Reveals New id Tech, Platform Details (Updated) |url=http://www.shacknews.com/article/47360/ea-and-id-renew-mac |access-date=2026-05-13 |website=Shacknews |language=en}}</ref> the engines were simply referred to by the names of the games the engines had been developed for. The ''Quake II'', ''Quake III Arena'' and ''Doom 3'' engines were retroactively renamed to id Tech 2, 3 and 4, respectively.<ref name=":0">{{Cite web |title=id Software: Technology Licensing |url=http://www.idsoftware.com/business/technology/ |archive-url=https://web.archive.org/web/20071006105034/http://www.idsoftware.com/business/technology/ |archive-date=2007-10-06 |access-date=2026-05-13 |website=www.idsoftware.com}}</ref>
"id Tech 1" was not used as an official name for any engines. The name "id Tech 2" might refer to its direct predecessor, the ''Quake'' engine being the first in a line of succession. However, according to a 2007 ''FiringSquad'' article, then-CEO Todd Hollenshead considered the ''Doom'' engine as "id Tech 1", with the ''Quake'' and ''Quake II'' engines sharing the "id Tech 2" name.<ref>{{Cite web |last=Firingsquad |title=Rage: id Tech 5 First Look |url=https://firingsquad.com/games/id_software_rage/ |archive-url=https://web.archive.org/web/20070929083458/https://firingsquad.com/games/id_software_rage/ |archive-date=2007-09-29 |access-date=2026-05-13 |website=firingsquad.com}}</ref>
id Software's licensing site didn't feature an "id Tech 1", only id Tech 2 for Quake II. Before the introduction of the brand in 2007, the licensing page only featured the three Quake engines.<ref>{{Cite web |title=id Software's Technology Licensing Program |url=http://www.idsoftware.com/business/technology/techlicense.php |archive-url=https://web.archive.org/web/20070712095652/http://www.idsoftware.com/business/technology/techlicense.php |archive-date=2007-07-12 |access-date=2026-05-13 |website=www.idsoftware.com}}</ref><ref name=":0" /><ref>{{Cite web|url=https://web.archive.org/web/20070907031723/http://www.idsoftware.com/business/idtech2/|title=id Software: Technology Licensing}}</ref>
==Predecessors== id Software had developed pseudo-3D engines for several games before ''Quake''. Each engine had progressively more advanced pseudo-3D technology. Two notable examples are the ''Wolfenstein 3D'' engine and the ''Doom'' engine. All of the following are fundamentally different in architecture and rendering technology from later id Software game engines, which are fully 3D rendered with separated engine and game code. * ''Hovertank 3D'' (1991) used solid-color drawn polygonal walls and scalable sprites. The source code was released by Flat Rock Software in June 2014 under GPL-2.0-or-later. * ''Catacomb 3-D'' (1991) added texture mapping to the walls. The source code was released by Flat Rock Software in June 2014 under GPL-2.0-or-later.
=== ''Wolfenstein 3D'' engine === {{Main|Wolfenstein 3D engine}} {{Main|Rise of the Triad}} ''Wolfenstein 3D'' (1992) increased the color palette from 16-color EGA to 256-color VGA and also adopted raycasting. The game engine was also licensed out to other companies. The source code to Wolfenstein 3D, along with its prequel ''Spear of Destiny'', was released on 21 July 1995 under a proprietary license, and then later under GPL-2.0-or-later.<ref>{{cite web |last=Carmack |first=John |date=March 20, 2009 |url=https://github.com/id-Software/Wolf3D-iOS/blob/master/wolf3d/readme_iWolf.txt |format=TXT |title=readme_iWolf.txt |website=GitHub |access-date=February 26, 2024}}</ref><ref>{{cite web |last=Carmack |first=John |date=September 1, 2011 |url=http://metadata.ftp-master.debian.org/changelogs/contrib/w/wolf4sdl/wolf4sdl_1.7+svn262+dfsg1-1_copyright |title=Re: License of Wolf3d source code |website=metadata.ftp-master.debian.org |url-status=dead |archive-url=https://web.archive.org/web/20160120224538/http://metadata.ftp-master.debian.org/changelogs/contrib/w/wolf4sdl/wolf4sdl_1.7+svn262+dfsg1-1_copyright |archive-date=January 20, 2016 |access-date=February 26, 2024}}</ref>
''ShadowCaster'' (1993) was built upon the Wolfenstein 3D engine and was licensed out to Raven Software.<ref>{{cite web |last1=Antoniades |first1=Alexander |title=Monsters from the Id: The Making of Doom |url=https://www.gamedeveloper.com/business/monsters-from-the-id-the-making-of-i-doom-i- |website=Game Developer |publisher=Informa |access-date=13 July 2024 |date=22 August 2013}}</ref> It features diminished lighting, texture mapped floors and ceilings, walls with variable heights, and sloped floors.<ref name="ravensoft.com">{{cite web |url=http://www.ravensoft.com/gamesdetail.aspx?xmmid=624&xmid=4&xmview=2 |title=Shadowcaster at Ravensoft.com |access-date=2009-07-02 |publisher=Raven Software |url-status=dead |archive-url=https://web.archive.org/web/20090614054825/http://www.ravensoft.com/gamesdetail.aspx?xmmid=624&xmid=4&xmview=2 |archive-date=2009-06-14 }}</ref> This Raven engine was later also used by ''In Pursuit of Greed'', and with further modifications for ''CyClones'' as the STEAM engine.
''Rise of the Triad'' uses an enhanced engine of ''Wolfenstein 3D'' and was originally meant to serve as the sequel to it. The source code was released on 20 December 2002 under GPL-2.0-or-later.
Other games using this engine are: ''Blake Stone: Aliens of Gold'', ''Blake Stone: Planet Strike'', ''Corridor 7: Alien Invasion'', and ''Operation Body Count''.
=== ''Doom'' engine === {{Main|Doom engine}} The "'''''Doom'' engine'''" powers the id Software games ''Doom'' (1993), ''Doom II: Hell on Earth'' (1994) and ''Doom 64'' (1997). It was created by John Carmack, with auxiliary functions written by John Romero, Dave Taylor, and Paul Radek. Initially developed on NeXT computers, it was ported to MS-DOS for ''Doom''<nowiki>'</nowiki>s release and was later ported to several game consoles and operating systems. The source code was released on 23 December 1997 under a proprietary license, and then later on 3 October 1999 under GPL-2.0-or-later.<ref>{{Cite web|url=https://www.doomworld.com/idgames/source/doomsrc|title=Doom source code, under the GNU GPL - Doomworld /Idgames database frontend}}</ref>
''Heretic'' and ''Hexen: Beyond Heretic'' were developed by Raven Software and published by id Software. Their sources were released on 4 September 2008 under GPL-2.0-only. Other games using this engine include ''Strife: Quest for the Sigil'' and ''Chex Quest''.
==Development== {{VG timeline | compressempty = yes | 1996 = Quake engine | 1997 = id Tech 2 | 1999 = id Tech 3 | 2004 = id Tech 4 | 2011 = id Tech 5 | 2016 = id Tech 6 | 2020 = id Tech 7 | 2025 = id Tech 8 }} === ''Quake'' engine === {{Main|Quake engine}} It was originally written to power 1996's ''Quake''. It featured true 3D real-time graphics via software rendering and is the first id Software engine to use the client–server model and a virtual machine for game code written in ''QuakeC''. 3D model animations lack interpolation, appearing choppy and uneven. The source code was released on 21 December 1999 under GPL-2.0-or-later.
The ''Quake'' engine was updated with a new multiplayer-only executable titled ''QuakeWorld'' that contained code to enhance the networking capabilities of ''Quake'' in response to the demand for across-internet network games that arose as a result of ''Quake''{{'}}s usage of UDP for networking.
Another update was ''GLQuake'' and ''GLQuakeWorld'' which add support for 3D acceleration through OpenGL. However, both have limitations which include a lack of "fullbright" and "overbright" lighting present in the software renderer. <ref name="www.quaddicted.net">{{cite web|url=https://www.quaddicted.com/engines/software_vs_glquake|title=Differences between software rendered Quake and GLQuake - Quaddicted.com|publisher=quaddicted.com|access-date=2026-03-10}}</ref> === id Tech 2 === {{Main|Quake II engine}} Originally known as the "'''''Quake II'' engine'''", it was used to power id Software's ''Quake II'' in 1997, with features such as out-of-the-box support for hardware acceleration, enhanced network code, colored lighting, and a new vertex-interpolated MD2 model format.<ref>{{cite web|url=http://www.idsoftware.com/business/idtech2/|title=id Tech 2 page|publisher=id Software|archive-url=https://web.archive.org/web/20080917045739/http://www.idsoftware.com/business/idtech2/|archive-date=2008-09-17}}</ref> id Tech 2 also features alpha blending, radiosity lightmaps, and a modular architecture for the renderer and game code, both now written in C and compiled to shared libraries. The benefits of such are speed and easier debugging at the expense of portability. id Tech 2 is the last id Tech engine to include a software renderer. The source code was released on 22 December 2001 under GPL-2.0-or-later.
=== id Tech 3 === {{Main|id Tech 3}} Originally known as the "'''''Quake III Arena'' engine'''", it was used to power id Software's ''Quake III Arena'' in 1999. It is the first in this series to require an OpenGL-compliant graphics accelerator to run. id Tech 3 features higher precision vertex animation with the MD3 model format, volumetric fog, spline-based curved surfaces, precomputed form of portals similar to what is in Prey (2006 video game), decals, and material scripts. The ''Quake III Arena'' engine was updated to patch 1.26 and later versions are called "'''Quake III Team Arena engine'''" with a new MD4 skeletal model format and huge outdoor areas. The source code was released on 19 August 2005 under GPL-2.0-or-later.
id Tech 3 was updated with the 2001 release of ''Return to Castle Wolfenstein'', which included a single-player scripting system, and the 2003 release of ''Wolfenstein: Enemy Territory''. The source code was released on 12 August 2010 under GPL-3.0-or-later.
It was also licensed by Infinity Ward and modified for the first ''Call of Duty'' title in 2003, spawning the IW engine.
=== id Tech 4 === {{Main|id Tech 4}} Originally known as the "'''''Doom 3'' engine'''", which was used to power ''Doom 3'' as it released in 2004, id Tech 4 began as an enhancement to id Tech 3. During development, it was initially just a complete rewrite of the engine's renderer, while still retaining other subsystems, such as file access, and memory management. The decision to switch from C to the C++ programming language necessitated a restructuring and rewrite of the rest of the engine; today, while id Tech 4 contains code from id Tech 3, much of it has been rewritten.<ref>{{cite web|url=http://archive.gamespy.com/e32002/pc/carmack/|title=Q&A with John Carmack, E3 2002|publisher=GameSpy|archive-url=https://web.archive.org/web/20120124031112/http://archive.gamespy.com/e32002/pc/carmack/|archive-date=2012-01-24}}</ref> It features unified lighting, shadow volumes, shaders, normal mapping, specular mapping, the improved MD5 skeletal model format, interactive GUI rendered onto model surfaces, and real-time physics simulation. The source code was released on 22 November 2011 under GPL-3.0-or-later.
Other games using this engine are: Raven Software's ''Quake 4'' (2005) and ''Wolfenstein'' (2009), Human Head Studios' ''Prey'' (2006), Splash Damage's ''Enemy Territory: Quake Wars'' (2007) and ''Brink'' (2011).
id Tech 4 was updated with the 2012 release of ''Doom 3: BFG Edition'' with some features from id Tech 5. The source code was released on 26 November 2012 under GPL-3.0-or-later, and it is the last GPL licensed id Software release.
=== id Tech 5 === {{Main|id Tech 5}} thumb|150px|id Tech 5 was the first id Tech engine to receive its own logo. Used for id Software's ''Rage,'' the engine is based on the file system frameworks. Some technologies included are the GUI system from id Tech 4, including a new renderer, MegaTexture 2.0 technology, soft shadows and more.
The engine was later used to power MachineGames' first two ''Wolfenstein'' titles, ''The New Order'' in 2014 and its standalone expansion ''The Old Blood,'' from 2015. It was also used for Tango Gameworks' ''The Evil Within'' (2014).
id Tech 5 can no longer be licensed and is now proprietary to id's parent company, Bethesda Softworks.<ref>{{cite web|url=http://www.eurogamer.net/articles/2010-08-12-id-tech-5-only-for-bethesda-titles|title=id Tech 5 only for Bethesda titles|last=Bramwell|first=Tom|publisher=Eurogamer|date=2010-12-08|access-date=2017-08-15}}</ref> It is the oldest id Software engine not to be released under the GNU GPL license. According to then-CEO of id Software, Todd Hollenshead, the engine remains closed-source because it is a "competitive advantage and we want to keep it within games we publish -- not necessarily exclusively to id or id titles, but if you're going to make a game with id Tech 5 then it needs to be published by Bethesda, which I think is a fair thing."<ref>{{Cite web|last=Graft|first=Kris|title=id Tech 5 Rage Engine No Longer Up For External Licensing|url=https://www.gamedeveloper.com/programming/id-tech-5-i-rage-i-engine-no-longer-up-for-external-licensing|publisher=Gamasutra|access-date=August 12, 2018}}</ref>
=== id Tech 6 === {{Main|id Tech 6}} Used for ''Doom'' released on May 13, 2016. While the engine uses some of the features from id Tech 5, id has also added support for Vulkan rendering. Development of the renderer is led by Tiago Sousa, who had previously worked on CryEngine, following previous technical director John Carmack's resignation in 2013. id Tech 6 was also used in ''Wolfenstein II: The New Colossus'' (2017), and ''Wolfenstein: Youngblood'' (2019) again by MachineGames. It was not used for ''Quake Champions'' however, which combined id Tech features with the Saber3D Engine.
=== id Tech 7 === {{Main|id Tech 7}} At QuakeCon 2018, id Software announced the release of a new game in the Doom franchise called ''Doom Eternal''.<ref>{{Cite news |last=Machkovech |first=Sam |date=2018-10-08 |title=Doom Eternal ushers in idTech 7, bloody new powers |url=https://arstechnica.com/gaming/2018/08/doom-eternal-reveals-new-powers-puts-hell-back-on-earth/ |access-date=2018-08-10 |work=Ars Technica |language=en-us}}</ref> Powered by the id Tech 7 engine, ''Doom Eternal'' was released on March 20, 2020. The new engine is capable of delivering an increase in geometric detail without drops in frame-rate vs. id Tech 6.<ref>{{Cite news|url=https://wccftech.com/doom-eternal-debut-gameplay-quakecon/|title=Doom Eternal Unleashes Bloody Debut Gameplay at QuakeCon|last=Birch|first=Nathan|date=2018-08-10|work=Wccftech|access-date=2018-08-12|language=en-US}}</ref> On PC, id Tech 7 supports Vulkan rendering only.<ref>{{Cite tweet |number=1028133659168186368 |user=billykhan |title=Yes, it's #Vulkan only on PC. #Vulkan is the best API if you want to achieve the absolute highest frame rates on PC. |first=Billy |last=Khan |date=2018-08-11}}</ref>
=== id Tech 8 === At Developer_Direct 2025, id Software revealed gameplay details<ref>{{Cite web |title=New Gameplay Details Revealed for DOOM: The Dark Ages, Launching May 15, 2025 |url=https://slayersclub.bethesda.net/en-US/article/doom-the-dark-ages-gameplay-revealed |last=Wilhelm |first=Parker |date=2025-01-23 |access-date=2025-01-24 |website=Slayers Club}}</ref> and the PC specifications<ref>{{Cite web |title=Prepare for DOOM: The Dark Ages with our PC specs |url=https://slayersclub.bethesda.net/en-US/article/doom-the-dark-ages-pc-specs |last=Wilhelm |first=Parker |date=2025-01-23 |access-date=2025-01-24 |website=Slayers Club}}</ref> for ''Doom: The Dark Ages'', which is powered by their id Tech 8 engine and was released on May 15, 2025.
The id Tech 8 engine increases the maximum number of on-screen enemies and supports path tracing and realistic game physics, featuring destructible environments.<ref>{{Cite news |date=2025-04-01 |title=Doom: The Dark Ages hands-on tech preview - idTech 8 impresses hugely on PC |url=https://www.eurogamer.net/digitalfoundry-2025-doom-the-dark-ages-hands-on-tech-preview-id-tech-8-impresses-hugely-on-pc |access-date=2025-05-12 |work=Eurogamer.net |language=en}}</ref> It is the first generation of id Tech engine that requires dedicated raytracing-enabled hardware,<ref name="RTonly">{{Cite web |last=Roach |first=Jacob |date=2025-05-09 |title=Exploring the gory brilliance of id Tech 8 in Doom: The Dark Ages |url=https://www.xda-developers.com/doom-dark-ages-id-tech-hands-on/ |access-date=2025-05-12 |website=XDA |language=en}}</ref> primarily due to the lighting being fully raytraced global illumination.
==Comparison== {{main|List of game engines}} {| class="wikitable sortable" style="text-align: center; font-size: 85%; width: auto; table-layout: fixed;" |- ! style="width: 12em" | Name<br>{{small|(aka)}} ! Primary programming language ! Release year ! Open sourced? ! Game Code Language ! Platforms ! Notable games ! class="unsortable" | Notes and references |- ! ''Quake'' engine | C | 1996 | {{open source|1999, GPL-2.0-or-later}} | QuakeC | MS-DOS, Windows, Linux, macOS | ''Quake'', ''Hexen II'', ''Wrath: Aeon of Ruin'' | First true 3D id Tech engine; arbitrary geometry now possible. |- ! id Tech 2<br>{{small|''Quake II'' engine}} | C | 1997 | {{open source|2001, GPL-2.0-or-later}} | C | Windows, Linux, macOS | ''Quake II'', ''Heretic II'', ''SiN'', ''Daikatana'', ''Gravity Bone'', ''Thirty Flights of Loving'' | Colored lights, 3D Acceleration. |- ! rowspan="2" | id Tech 3<br>{{small|''Quake III Arena'' engine}} | C | 1999 | {{open source|2005, GPL-2.0-or-later}} | C | Windows, Linux, macOS | ''Quake III Arena'', ''Heavy Metal: F.A.K.K. 2'', ''American McGee's Alice'', ''Call of Duty'', ''Quake Live'' | Curved Surfaces, Volumetric Fog, Virtual Machine |- | C | 2001 | {{open source|2010, GPL-3.0-or-later}} | C | Windows, Linux, macOS | ''Return to Castle Wolfenstein'', ''Wolfenstein: Enemy Territory'' | Improvements to the id Tech 3 engine. |- ! rowspan="2" | id Tech 4<br>{{small|''Doom 3'' engine}} | C++ | 2004 | {{open source|2011, GPL-3.0-or-later}} | C++, custom scripting for GUI elements | Windows, Linux, macOS | ''Doom 3'', ''Quake 4'', ''Prey'', ''Enemy Territory: Quake Wars'', ''Wolfenstein'', ''Brink'', ''Quadrilateral Cowboy'' | Among many new features, interactive GUI surfaces and unified lighting with stencil shadows. First id Tech engine to support normal mapping. |- | C++ | 2011 | {{open source|2012, GPL-3.0-or-later}} | C++, Adobe Flash for GUI elements | Windows, Linux, macOS | ''Doom 3: BFG Edition'' | Improvements to the id Tech 4 engine. GUI scripting system replaced with Flash. |- ! id Tech 5 | C++, AMPL, Clipper, Python | 2011 | {{proprietary}} | Script | Windows, macOS, Xbox 360, Xbox One, PlayStation 3, PlayStation 4 | ''Rage'', ''Wolfenstein: The New Order'', ''Wolfenstein: The Old Blood'', ''The Evil Within'' | First id Tech engine to feature MegaTexture technology, starting with ''Rage'' |- ! id Tech 6 | C++ | 2016 | {{proprietary}} | Unknown | Windows, Xbox One, PlayStation 4, Nintendo Switch | ''Doom (2016), Wolfenstein II: The New Colossus'' | |- ! id Tech 7 | C++ | 2020 | {{proprietary}} | Unknown | Windows, PlayStation 4, Xbox One, Nintendo Switch | ''Doom Eternal'', ''Indiana Jones and the Great Circle'' | Much refactoring, MegaTexture removed, many additional new features |- ! id Tech 8 | C++ | 2025 | {{proprietary}} | Unknown | Windows, PlayStation 5, Xbox Series X/S | ''Doom: The Dark Ages'' | First version of the engine to require ''hardware-level'' ray-tracing<ref name="RTonly"/> |}
==See also== * First-person shooter engine * List of game engines
==References== {{Reflist|2}}
==External links== *[https://github.com/id-Software Source code of open source engines released by id Software]
{{Id Software}} {{ZeniMax Media}} {{Video game engines}}
Category:Id Tech Category:Game engines for Linux Category:Video game engines