id Tech is a series of successive

game engine A game engine is a software framework primarily designed for the development of video games which generally includes relevant libraries and support programs such as a level editor. The "engine" terminology is akin to the term " software engine" u ...

s designed and developed by

id Software id Software LLC () is an American video game developer based in Richardson, Texas. It was founded on February 1, 1991, by four members of the computer company Softdisk: game programmer, programmers John Carmack and John Romero, game designer T ...

. Prior to the presentation of the

id Tech 5 id Tech 5 is a proprietary software, proprietary game engine developed by id Software. It followed its predecessors, id Tech 1, id Tech 2, 2, id Tech 3, 3 and id Tech 4, 4, all of which had subsequently been published under the GNU General Publi ...

-based game '' Rage'' in 2011, the engines lacked official designation and as such were simply referred to by the names of the games the engines had been developed for (i.e., ''

Doom Doom is another name for damnation. Doom may also refer to: People * Doom (professional wrestling), the tag team of Ron Simmons and Butch Reed * Daniel Doom (1934–2020), Belgian cyclist * Debbie Doom (born 1963), American softball pitche ...

'' and '' Quake'' engines). The id Tech engines up through 4.5 have been released as

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

under the

GNU General Public License The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

. id Tech versions 0 to 3 were released under GPL-2.0-or-later; id Tech versions 3.5 to 4.5 were released under GPL-3.0-or-later. id Tech 5 to 7 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 id Tech 4, popularly known as the ''Doom 3'' engine, is a game engine developed by id Software and first used in the video game ''Doom 3''. The engine was designed by John D. Carmack, John Carmack, who also created previous game engines, such a ...

had far fewer licensees than the

Unreal Engine Unreal Engine (UE) is a 3D computer graphics game engine developed by Epic Games, first showcased in the 1998 first-person shooter video game '' Unreal''. Initially developed for PC first-person shooters, it has since been used in a variety of ...

from

Epic Games Epic Games, Inc. is an American Video game developer, video game and software development, software developer and video game publisher, publisher based in Cary, North Carolina. The company was founded by Tim Sweeney (game developer), Tim Sween ...

. id planned to regain the momentum with

, until the company was bought by

ZeniMax Media ZeniMax Media Inc. is an American video game holding company based in Rockville, Maryland. The company was founded in 1999 by Christopher Weaver and Robert A. Altman as the parent company for Weaver's video game publisher Bethesda Softworks. ...

, which chose to keep the id Tech engines exclusively for id and its sister studios.

Predecessors

In the id Tech numbering system, the earliest engine to bear the name is either id Tech 1 (used for the original ''Doom'') or id Tech 0, retroactively applied to ''

Wolfenstein 3D ''Wolfenstein 3D'' is a 1992 first-person shooter game developed by id Software and published by Apogee Software and FormGen for DOS. It was inspired by the 1981 Muse Software video game '' Castle Wolfenstein'', and is the third installment ...

''. However, id Software had developed 3D engines for several games before ''Wolfenstein 3D''. Each engine had progressively more advanced 3D technology. * ''

Hovertank 3D ''Hovertank One'', also known under a variety of other names (''Hovertank'' or ''Hovertank 3D''), is a vehicular combat game developed by id Software and published by Softdisk in April 1991. Plot ''Hovertank One'' is set during a nuclear war. ...

'' (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 Texture mapping is a term used in computer graphics to describe how 2D images are projected onto 3D models. The most common variant is the UV unwrap, which can be described as an inverse paper cutout, where the surfaces of a 3D model are cut ap ...

to the walls. The source code was released by Flat Rock Software in June 2014 under GPL-2.0-or-later.

Wolfenstein 3D engine

'' (1992) increased the color palette from 16-color EGA to 256-color

VGA Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the IBM PC compatible industry within three years. T ...

and also adopted

raycasting Ray casting is the methodological basis for 3D CAD/CAM solid modeling and image rendering. It is essentially the same as ray tracing for computer graphics where virtual light rays are "cast" or "traced" on their path from the focal point of a came ...

. The

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. '' ShadowCaster'' (1993) was built upon the Wolfenstein 3D engine and was licensed out to

Raven Software Raven Software Corporation (trade name: Raven; formerly Raven Software, Inc.) is an American video game developer based in Middleton, Wisconsin, and part of Activision. Founded in May 1990 by brothers Brian and Steve Raffel, the company is most ...

. It features diminished lighting, texture mapped floors and ceilings, walls with variable heights, and sloped floors. This Raven engine was later also used by '' In Pursuit of Greed'', and with further modifications for ''

CyClones In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an ant ...

'' as the STEAM engine. ''Rise of the Triad'' uses an enhanced engine of ''Wolfenstein 3D'' and was 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'', '' Operation Body Count'', and, with several modifications, ''

Rise of the Triad ''Rise of the Triad: Dark War'' is a first-person shooter video game, developed and published by Apogee Software (now 3D Realms) in 1995. The player can choose to play as one of five different characters, each bearing unique attributes such a ...

''.

Development

id Tech 1

Originally known as the "''Doom'' engine", this engine powers the id Software games ''

'' (1993), '' Doom II: Hell on Earth'' (1994) and ''

Doom 64 ''Doom 64'' is a 1997 first-person shooter game developed and published by Midway Games for the Nintendo 64. It is the second spin-off in id Software's ''Doom'' series after '' Final Doom'' (1996), and the fourth game in the series overall. ...

'' (1997). It was created by

John Carmack John D. Carmack II (born August 21, 1970) is an American computer programmer and video game developer. He co-founded the video game company id Software and was the lead programmer of its 1990s games ''Commander Keen'', ''Wolfenstein 3D'', ''Do ...

, with auxiliary functions written by

John Romero Alfonso John Romero (born October 28, 1967) is an American video game developer. He co-founded id Software and designed their early games, including ''Wolfenstein 3D'' (1992), ''Doom (1993 video game), Doom'' (1993), ''Doom II'' (1994), ''Hexen ...

, Dave Taylor, and Paul Radek. Initially developed on

NeXT NeXT, Inc. (later NeXT Computer, Inc. and NeXT Software, Inc.) was an American technology company headquartered in Redwood City, California that specialized in computer workstations for higher education and business markets, and later develope ...

computers, it was

ported In software engineering, porting is the process of adapting software for the purpose of achieving some form of execution in a computing environment that is different from the one that a given program (meant for such execution) was originally desig ...

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...

for ''Doom'''s release and was later ported to several

game console A video game console is an electronic device that outputs a video signal or image to display a video game that can typically be played with a game controller. These may be home consoles, which are generally placed in a permanent location conne ...

s and

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

s. 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. ''

Heretic Heresy is any belief or theory that is strongly at variance with established beliefs or customs, particularly the accepted beliefs or religious law of a religious organization. A heretic is a proponent of heresy. Heresy in Christianity, Judai ...

'' and '' Hexen: Beyond Heretic'' were developed by

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 ''Chex Quest'' is a non-violent first-person shooter video game created in 1996 and released in 1997 by Digital Café, originally intended as a Chex cereal promotion aimed at children aged 6–9 and up.Thompson, Stephanie. "WatersMolitor Promo ...

''.

id Tech 2

Originally known as the "''Quake'' engine", it was originally written to power 1996's '' Quake''. It featured true 3D

real-time rendering Real-time computer graphics or real-time rendering is the sub-field of computer graphics focused on producing and analyzing images in real time. The term can refer to anything from rendering an application's graphical user interface ( GUI) to ...

and is the first id Tech engine to use the

client–server model The client–server model is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. Often clients and servers communicate ov ...

. The source code was released on 21 December 1999 under GPL-2.0-or-later. The ''Quake'' engine was updated with a new executable titled ''

QuakeWorld ''Quake'' is a 1996 first-person shooter game developed by id Software and published by GT Interactive. The first game in the ''Quake'' series, it was originally released for MS-DOS and Microsoft Windows, followed by Mac OS, Linux and Sega S ...

'' 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. id Tech 2 was later updated for the release of ''

Quake II ''Quake II'' is a 1997 first-person shooter, first-person shooter game developed by id Software and published by Activision. It is the second installment of the Quake (series), ''Quake'' series, following ''Quake (video game), Quake''. Develope ...

'' in 1997, with enhancements such as colored lighting and a new MD2 model format. This updated version of 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

Originally known as the "''Quake III Arena'' engine", it was used to power id Software's ''

Quake III Arena ''Quake III Arena'' is a 1999 first-person shooter game developed by id Software. The third installment of the ''Quake'' series, ''Arena'' differs from previous games by excluding a story-based single-player mode and focusing primarily on mult ...

'' in 1999. 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. id Tech 3 is the first in this series to require an

OpenGL OpenGL (Open Graphics Library) is a Language-independent specification, cross-language, cross-platform application programming interface (API) for rendering 2D computer graphics, 2D and 3D computer graphics, 3D vector graphics. The API is typic ...

-compliant graphics accelerator to run. 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 ''Return to Castle Wolfenstein'' is a 2001 first-person shooter, first-person shooter game developed by Gray Matter Studios and published by Activision. It was initially released for Microsoft Windows and subsequently for the PlayStation 2 (as '' ...

'', which included a single-player scripting system. id Tech 3 was also used to power the first ''Call of Duty'' title in 2003, ultimately spawning the

IW engine The IW engine is a game engine created and developed by Infinity Ward, with the current iteration developed in its studio in Kraków, Poland for the Call of Duty, ''Call of Duty'' series. The engine was originally based on id Tech 3 by id Softwa ...

. It was also used for '' Wolfenstein: Enemy Territory''. The source code was released on 12 August 2010 under GPL-3.0-or-later.

id Tech 4

Commonly known as the "''

Doom 3 ''Doom 3'' is a 2004 first-person shooter, first-person shooter game developed by id Software and published by Activision. ''Doom 3'' was originally released for Microsoft Windows on August 3, 2004, adapted for Linux later that year, and Vide ...

'' engine" which was used to power ''Doom 3'' as it released in 2004, id Tech 4 began as an enhancement to

id Tech 3 id Tech 3, popularly known as the ''Quake III Arena'' engine, is a game engine developed by id Software for its 1999 game ''Quake III Arena''. It has subsequently been used in numerous games. Commercially, id Tech 3 competed with early version ...

. 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 A programming language is a system of notation for writing computer programs. Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually def ...

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. The source code was released on 22 November 2011 under GPL-3.0-or-later. Other games using this engine are:

's '' Quake 4'' (2005) and ''

Wolfenstein ''Wolfenstein'' is a series of alternate history World War II video games originally developed by Muse Software. The majority of the games follow William "B.J." Blazkowicz, an American Army captain, and his fight against the Axis powers. Earlie ...

'' (2009),

Human Head Studios Human Head Studios, Inc. was an American video game developer located in Madison, Wisconsin. History Human Head Studios was founded in October 1997 by a group of six developers formerly from Raven Software: Ben Gokey, Chris Rhinehart, Paul M ...

' ''

Prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

'' (2006),

Splash Damage Splash Damage Ltd. is a British video game developer specialising in multiplayer first-person shooter video games. The studio is best known as the creators of '' Wolfenstein: Enemy Territory'' and '' Enemy Territory: Quake Wars''. History ...

'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.

id Tech 5

Used for id Software's '' Rage,'' the engine is based on the file system frameworks. Some technologies included are the GUI system from

, including a new renderer, MegaTexture 2.0 technology, soft shadows and more. id is requiring companies that use the engine to publish their games through id's sister company,

Bethesda Softworks Bethesda Softworks LLC is an American video game publisher based in Rockville, Maryland. The company was founded by Christopher Weaver in 1986 as a Division (business), division of Media Technology Limited. In 1999, it became a subsidiary of Z ...

. The engine was later used to power

MachineGames MachineGames Sweden AB is a Swedish video game developer based in Uppsala. The studio was founded in 2009 by seven former employees of Starbreeze Studios, including founder Magnus Högdahl. After unsuccessfully pitching game ideas to several ...

' 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 Tango Gameworks Inc. is a Japanese video game developer based in Tokyo. Founded in March 2010 by Shinji Mikami, previously of Capcom, the company was acquired by ZeniMax Media in October that year after suffering financial issues. Tango develo ...

' ''

The Evil Within ''The Evil Within'' is a 2014 survival horror, survival horror game developed by Tango Gameworks and published by Bethesda Softworks. It was directed by ''Resident Evil'' series creator Shinji Mikami. The game centers on protagonist Sebastian Ca ...

'' (2014). id Tech 5 is currently the oldest id Software engine not to be released under the GNU GPL license. As of 2025, the engine remains

closed-source Proprietary software is software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing the software or modi ...

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 Vulkan is a cross-platform API and open standard for 3D graphics and computing. It was intended to address the shortcomings of OpenGL, and allow developers more control over the GPU. It is designed to support a wide variety of GPUs, CPUs and o ...

rendering. Development of the renderer is led by Tiago Sousa, who had previously worked on

CryEngine CryEngine (stylized as CRYENGINE) is a game engine designed by the German game developer Crytek. It has been used in all of their titles with the initial version being used in ''Far Cry (video game), Far Cry'', and continues to be updated to sup ...

, following previous

technical director A technical director (TD) is usually a senior technical person within e.g. a software company, engineering firm, film studio, theatre company or television studio. They are responsible for overseeing and coordinating all of the technical aspect ...

's resignation in 2013. id Tech 6 was also used in '' Wolfenstein II: The New Colossus'' (2017), and '' Wolfenstein: Youngblood'' (2019) again by

. It was not used for '' Quake Champions'' however, which combined id Tech features with the Saber3D Engine.

id Tech 7

QuakeCon QuakeCon is a yearly convention held by ZeniMax Media to celebrate and promote the major franchises of id Software and other studios owned by ZeniMax. It includes a large, paid, bring-your-own-computer ( BYOC) LAN party event with a competiti ...

2018, id Software announced the release of a new game in the Doom franchise called ''

Doom Eternal ''Doom Eternal'' is a 2020 first-person shooter game developed by id Software and published by Bethesda Softworks. The sequel to '' Doom'' (2016), and the seventh game in the ''Doom'' series, it was released for PlayStation 4, Stadia, Wind ...

''. 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. On PC, id Tech 7 supports

rendering only.

id Tech 8

At Developer_Direct 2025, id Software revealed gameplay details and the PC specifications 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 Path tracing is a rendering algorithm in computer graphics that Simulation, simulates how light interacts with Physical object, objects, voxels, and Volumetric_path_tracing, participating media to generate realistic (''physically plausible'') R ...

and realistic

game physics Computer animation physics or game physics are laws of physics as they are defined within a simulation or video game, and the programming logic used to implement these laws. Game physics vary greatly in their degree of similarity to real-world phy ...

, featuring destructible environments. It is the first generation of id Tech engine that requires dedicated raytracing-enabled hardware, primarily due to the lighting to be fully raytraced global illumination.

Comparison

References

External links

Source code of open source engines released by id Software
{{Video game engines Id Tech Game engines for Linux Video game engines