Free & Open Source FPS Games
341 free, open-source fps games — real clones and remakes you can download, inspect the source of, and modify. Not just free to play: the code itself is open.
Archived
Clone of Command & Conquer: Renegade
Electronic Arts' official open-source release of the Renegade engine, paired with a Steam re-release adding Workshop support for user maps.
Sporadic
Halted
Active
Original game image
Original game imageClone of Half-Life 2
Valve's official SDK release with the game code for Half-Life 2, HL2: Deathmatch, and Team Fortress 2, for building mods.
Halted
Original game image
Original game imageClone of Quake 3
id Software's official GPL source release for Quake III Arena, including its full renderer, game code, and Q3Radiant editor.
Halted
Halted
Original game image
Original game imageClone of Doom 3
id Software's Doom 3 BFG Edition GPL source release, code only, omitting features like Steam integration and Bink video playback.
Halted
Active
Clone of S.T.A.L.K.E.R.
A community-improved X-Ray Engine for S.T.A.L.K.E.R. with 64-bit support, bug fixes and Linux/macOS ports.
Platforms:Windows
Stars3,559
Updated1 month ago
LicenseUnknown
Release2014
Genre: FPS
Theme: Alternate Historical
Halted
Halted
Clone of Serious Sam: The First Encounter
Croteam's official open-source release of Serious Engine 1.10, the toolchain behind the original Serious Sam Classic games.
Active
Sporadic
Active
Halted
Original game image
Original game imageClone of Wolfenstein 3D
id Software's official 1992 GPL source release for Wolfenstein 3D's DOS engine, including John Carmack's own retrospective notes.
Active
Clone of Doom
A source port that reproduces the original DOS Doom, Heretic, Hexen, and Strife with their original bugs intact on modern systems.
Active
Active
Halted
Original game image
Original game imageClone of Quake 2
id Software's official source for the 2023 Quake II Rerelease's game-logic DLL, merging all four expansion codebases into one.
Sporadic
Active
Original game image
Original game imageClone of Perfect Dark
A work-in-progress port of the Perfect Dark decompilation to modern platforms.
Stars2,037
Updated3 months ago
LicenseMIT
Release2023
Genre: FPS
Theme: —
Active
Clone of Doom 3
RBDOOM-3-BFG is a deeply modernized DOOM 3 BFG source port with PBR rendering and DX12/Vulkan support.
Sporadic
Active
Halted
Original game image
Original game imageClone of System Shock
Night Dive Studios' GPL-licensed release of System Shock's 1994 classic Mac OS source code, without game data.
Active
Halted
Halted
Clone of Ace of Spades
An open-source, cross-platform client for Ace of Spades 0.75 that connects to vanilla, pyspades and pysnip servers.
Platforms:WindowsOSX
Stars1,245
Updated2 years ago
LicenseGPL-3.0
Release2013
Genre: FPS
Theme: World War II
Active
Original game image
Original game imageClone of Cube 2: Sauerbraten
Inexor is an open-source, MIT-licensed C++/Vulkan renderer for a planned 3D octree game engine, running on Windows and Linux.
Active
Halted
Active
Clone of Dark Forces
The Force Engine is a reverse-engineered rebuild of the Jedi Engine, currently offering full Dark Forces support with modern upgrades.
Active
Clone of Gloom (Quake)
An open-source arena shooter blending FPS combat with RTS base-building, inspired by mods like Natural Selection.
Active
Clone of Unreal Tournament
A reimplementation of Unreal Engine 1 aiming to run the original Unreal and Unreal Tournament using your own game files.
Active
Clone of Wolfenstein 3D
C-Dogs SDL is an actively maintained SDL port of C-Dogs, adding 4-player co-op, deathmatch, and over 100 user campaigns.
ActiveOriginal game image
Original game imageClone of Quake 2
An enhanced, actively maintained Quake II client with widescreen, modern controller, and OpenGL 3.2 support.
Active
Clone of Doom
Crispy Doom is a limit-removing Doom source port with higher resolution, widescreen, and uncapped framerate, staying demo-compatible.
Active
Clone of System Shock
An SDL2 cross-platform source port of System Shock, based on Night Dive Studios' released PowerPC source.
