# Truly Libre Games

This webpage lists games that are truly libre, as far as I was able to check. I am creating this list for myself and people who really care about free as in freedom games. This page is created by me, drummyfish (Miloslav Číž), and I release all original content on this webpage (linked images aren't included in this) under CC0 1.0, public domain. The page uses Aileron CC0 font by dot colon.

## FAQ

What are libre games?
  Libre games (also free games) are basically ethical video games. A libre game is both completely free software and completely free cultural work – that is free as in freedom. This means that the whole game (including sourtce code, assets, data etc.) is available to anyone and allows anyone to use it, study it, modify it and share it, in any way and for any purpose (even commercial). (Legal conditions that don't infringe on freedom right are allowed, e.g. the requirement of crediting the game's original author.) Libre games respect the user's freedom, support creativity and have many other advantages. These typically include zero price (being free as in beer), no ads, no spyware, no viruses, portability, extreme moddability, added educational value, preservability and much more. Libre games are games that don't bother you and don't abuse you.
What are the criteria for a game to be included here?
  I will only include libre games passing very strict criteria which I myself personally verify and test, as I care about free culture principles very much. I won't trust any free SW repository alone as I have always been able to find some non-free files in any free SW repository (even in the Debian package repository etc.). The goal is to assure the complete game, in a wide sense, can be both legally and practically used and modified in any way and for any purpose, without the risk of legal punisment and legal or practical obstacles. The criteria are:
  - The game must be at least a little bit playable and valuable in its current state. I.e. it doesn't have to be finished, but if it doesn't offer anything or isn't a complete game (e.g. by only being an engine), it doesn't pass.
  - The game must be legally completely free software and this must be proven beyond any reasonable doubt, i.e. the autorship must be clear plus the author's clear statement of a free license applying to all source code files must be present. Any third party code used by this project must also meet this criteria, and the game must comply with their licenses (e.g. proper attribution if required). These criteria also apply to any code downloaded at runtime and to all works this work is derived from.
  - The game must be completely free software practically, i.e. without any obfuscation or any other obstacles to the four basic freedoms.
  - All game content (assets, data and other asociated "intellectual property") must be legally a free cultural work, worldwide, meeting the same criteria as the game's code. I.e. the autorship and license must be proven beyond any reasonable doubt which also applies to any included third party content (just as with the game's code), to all works this work is derived from and to any content downloaded by the game at run time. Non-free assets under "fair use" or author's permission are unacceptable (this applies to all files, even fonts etc.). Source code for assets isn't required as long as the asset itself is reasonably editable in its final form (e.g. GIMP project files are not required for images created with GIMP).
  - All game content must be free cultural works practically (i.e. without any obstacles to conditions of freedom such as formats editable only by proprietary software).
  - The game must be compileable, modifiable and playable on systems consisting solely of completely free software.
  - Borderline legal cases won't pass. I.e. if it is not clear whether a game is different enough from the original as to not infringe on the original's copyright, it won't be included.
  - Relying on peculiar IP laws that are in danger of being retroactively changed (as is happening) and/or are very specific to countries such as the US, legal speculations, tricking authors to accept a free license and other shady/dangerous/questionable practices will probably lead to the game's rejection.
  - Similarly to Wikimedia Commons, trademarked content in games will mostly be ignored (as long it's not of great extent, e.g. using real names of famous players in a soccer game) because it is not possible to dodge all existing trademarks emerging around the world constantly, especially when a TM can be as simple as a single color or simple shape. Copyright is the main focus of these criteria, but other relevant forms of IP such as moral rights, patents or trade dress also play a role in judging the level of freedom offered by the game.
Why do this when sites like libregamewiki (LGW) or freegamedev (FGD) forums exist?
  Because these sites are sometimes very lax in checking the legal status of games, there are many people in the community who don't care or know very much about software and cultural freedom and by being an open community to which anyone can contribute many unlegitimate games get added by lack of knowledge, negligience or even intentionally. You may encounter vandalism and other dangerous factors because of which you're under certain risk, you're forced to double check everything. This page is here to save you the work. And also, this place is a beautiful plain HTML/CSS suckless page (another form of freedom).
Why do we need to be so strict?
  I'm not going to discuss here why free SW and free culture should be subscribed to, there are whole books about the topic. I am so strict about these principles because when I am investing part of my life into a game (by playing it, improving it, getting emotionally attached to it etc.), I need to know for certain it is completely free so that I can treat it that way (improve it, share it, know that no one can forcefully take it down etc.). One of the worst things is investing part of yourself, perhaps whole years, into a piece of art under a false belief you can freely enjoy it, share it and improve it, and then finding out you've just been mislead and you cannot do what you thought you could do (e.g. create a fan fiction based on the work etc.). Here I try to separate the games that are here to make your life better from those that just pretend and under a false title will in fact abuse you in some way.
How do I search this list?
  ctrl+F
How do I download the site's data?
  The data is literally the HTML. Use wget or right click the page.
How do I add a game to this list?
  Check if the game isn't among rejected games and if not, send me a mail to drummyfish@disroot.org and I will check it out, but it may take me long.

## Games

game | tags | media | description | status | links
--- | --- | --- | --- | --- | ---
Anarch | shooter, FPS, suckless, C |  | Extremely small, completely public domain, no-dependency, no-file, portable suckless anarcho-pacifist from-scratch 90s-style Doom clone that runs everywhere, made for the benefit of all living beings. Anarch has 10 levels, 6 weapons with different ammo and 7 types of enemies. | finished, 12.06.2021 (v. 1.02d, 2840f6f7a2): everything from scratch (even font, palette etc.) by single author, clearly (LICENSE + README statement) CC0 + extra waiver of patents/TMs, all 100% PD, compiled on X200 Devuan with only gcc (clang etc.) and SDL2 + SDL2-mixer (has other frontends too) | web, itch, code, archived
Azimuth | action-adventure, sci-fi, C |  | 2D top-down sci-fi space action adventure with a nice backstory and a visually pleasing vector graphics. | finished, 08.06.2021 (v. 1.0.3, 56f24f56eaf7...): clearly GPL (readme, source headers, website), suckless C, compiled nicely on X200 Devuan (seems to only require SDL), not many assets, all in the form of source code (so we suppose GPL), including author's own tiny vector font, and music (seems to be using custom tiny "MIDI"-like txt format and synthesizer), author also allows CC-BY for music (suggesting it's his work) | web, code, archived
Curse of War (terminal) | strategy, RTS, C |  | Fast-paced real time strategy in the terminal in which the player doesn't control individual units but rather focuses on high level management. Can be played offline with AI or in multiplayer over the network. | finished, 18.07.2021 (v. 1.1.8, 68b48bfd1b066...): this is for the terminal only version before SDL frontend (that one has unclear assets), clearly GPLv3 (LICENSE and headers), no assets, suckless C, compiled on X200 Devuan with simple "make" | web, code, archived
GNU Chess | chess, board, terminal, C++ |  | Strong chess engine that can be played in terminal, but also with many graphical frontends. | finished, 06.07.2021 (v. 6.2.9-pre3): only source, clearly licensed GPLv3 (COPYING), compiled on X200 Devuan, accepted by GNU savannah and Debian, even make scripts have license headers | code, archived
LibreMarcher | fractal, 3D, race |  | Run a marble over a surface of 3D fractals to the finish as fast as possible. | finished, 16.07.2021 (0489cc9e7de5...): GPLv2 (LICENSE, code and shader headers), compiled on and run on X200 Devuan (needs SFML and Eigen3), only a few assets, basically all CC0 and from scratch (clearly mentioned in readme) | code, archived
MicroTD | strategy, C |  | Tiny and very portable tower defense game with 8 different towers, 11 enemy types and 6 maps. | finished, 09.12.2021 (3f65c797cfe0...): clearly CC0 (source and LICENSE), made by single author, written in C99 using custom portable CC0 library, compiles extremely easily (X200 Devuan), has many ports. | code, archived
minecurses | terminal, C |  | Classic minesweeper, in terminal, with colors and mouse support but playable with keyboard alone. | playable, 12.07.2021 (dbbff0eb8bd7...): GPLv2 (LICENSE), only a few files, easily compiled on X200 Devuan (seems to only need ncurses) | code, archived
nbsdgames | minigames, terminal, C |  | Collection of 15+ suckless minigames (sudoku, minesweeper, jewels, battleships, snake, ...) running in terminal. | playable, 06.07.2021 (37dbbe829da...): CC0 + license URL linked in LICENSE, clear statement of PD, very few contributors, CC0 has been adopted before any contributions, compiled on X200 Devuan (only needs libncurses5-dev), has many ports | code, archived
Parallel Overhead | endless runner, C |  | Colorful endless runner with two spaceships in an infinite tunnel. | finished, 07.07.2021 (d85da03320f...): clear MIT license (README + all source header have author + license), suckless C, compiled on X200 Devuan (seems to just need SDL), only a few assets, all with authors + licenses, most assets also have source code (except for music LMMS project, but it can still be edited pretty freely) | code, code, archived
Simon Tatham's Portable Puzzle Collection | minigames, C |  | Collection of 35+ very portable minigames (minesweeper, untangle, pegs, fifteen, tracks, ...) running in simple GUI. | playable, 06.07.2021 (8f3413c31f...): only code under Expat (MIT) license, clearly stated in repo and also website (also in own words), with a list of authors, compiled smoothly on X200 Devuan (only seems to need GTK+ lib), has other frontends and ports | web, code, archived
Venzone | platformer, terminal, Haskell |  | Cute ASCII-art platformer/adventure in terminal, with the possibility to create custom levels and stories. | finished, 09.07.2021 (v. 1.0.0.5): clearly GPL (COPYING, assets/readme.txt), list of suthors, compiled on X200 Devuan, only a handful of txt "assets" (ASCII art menu, levels) | web, code, archived
2048-in-terminal | puzzle, terminal, C |  | The popular puzzle 2048 in terminal, with colors and animated movement of tiles, nice and simple. | finished, 11.07.2021 (8453a8859f8e...): MIT (COPYING file), suckless, only a few C files, compiled on X200 Devuan with simple "make" (only needs ncurses), repo contains preview gif that may contain non-free font in terminal but this doesn't really matter (it's not part of the game and isn't violating law) | code, archived

## Rejected Games

Alex the Allegator 4
  Data license was unclear, author was contacted and responded saying he doesn't apply the license to the assets.
Colossal Cave Adventure (in bsdgames)
  06.07.2021: There are theories the game is PD but they seem to be speculations relying on some peculiarities of the US law, i.e. a danger of retroactive law change and non-PD status outside the US, the original FORTRAN version (of which all other versions are derivative works) comes with no modern comments, royalties were paid for the game, the original authors don't seem to be wanting to clarify this (otherwise they would have added some comments to the readme), all in all this doesn't look completely safe so until a more conclusive evidence this is rejected.
Freedoom
  07.07.2021: Unfortunately seems visually too similar to Doom and so infringing on trade dress, one could arguably easily confuse Freedoom with Doom, also considering legal precedents of lost cases in this matter exist, and that this is not something that would easily be fixed (all assets would basically have to be completely remade), and also that Freedoom's goal is basically to closely resemble Doom for compatibility reasons, so there are the same number of levels with basically the same weapons and pretty similar monsters, UAC is just renamed to AGM, GUI has the same colors and layouts with extremely similar font etc., all in all a very real danger of legal trouble exists e.g. in case of commercial use.
Inter-Continental Ballistic Missiles, 3D (ICBM3D)
  The game contains complete lyrics to a copyrighted song We Will All Go Together When We Go by Tom Lehrer.
Marble Marcher
  06.07.2021: Sound and music files don't have a license attached or sources listed (only vague "music by PettyTheft" is seen in the game menu) and overall licensing is unclear (not clear which license files apply to which fonts etc.). Potentially an easy fix (remove that stuff).
Neverball
  06.07.2021: Octocat GitHub mascot that's present in the game is not free. Permission has been given to use the mascot in the game, but that doesn't make it free, Neverball prior to addition of Octocat may be libre.
Pixel Wheels
  06.07.2021: There is a vehicle extremely similar to the copyrighted Batmobile (borderline legal case), some assets seem to be in proprietary Aseprite format (though conversion tools are provided, I am not sure they can be easily edited without Aseprite), there is about a billion of folders with billions of files (dangerous), android/assets/musics has mp3s without licenses (not clear which applies), same with fonts, wav sound effects without sources.
Ryzom
  06.07.2021: Server world data are proprietary and not published (source 1, source 2). Also resources are in proprietary formats (3DS Max, ...). An insider spoke about huge mess in development (bloat), using "open-source" only as a brand for making profit and many assets not being free-licenseable as they came from commercial samples. There's probably no hope.
SuperTuxKart
  06.07.2021: Data contain many files without a license (copyright file, search "license: ???", there are even assets like Wilhelm Scream). Beastie and Hexley mascots are distributed under non-free terms. Supposedly a permission has been granted to Beastie, but the the author seems confused and not aware he would relicense to GPL (wording + original terms on his web still stand), plus it's only a copy pasted email reply (not strong legal evidence). Later the author confirmed he doesn't want to license his mascot free.
Umoria
  06.07.2021: Seems to be taking place in the LOTR universe as the player is in a dungeon of Moria (which is a name LOTR invented, meaning "the black chasm" in one of Tolkien's languages) and battling a Balrog. This is a legal borderline case, so we rather reject this.

## TODO

- Me and My Shadow: licenses actuall nicely documented, but still not sure OFL confitions are met and unsure about sources of assets, samples in the music etc., so TODO: fork this and replace assets with custom CC0 ones
- bastet: seems fine
- Minetest (not sure if the game complies with "cryptsoft-License" in minetest-data, also trade dress vs Minecraft)
- Xonotic
- Extreme Tux Racer
- Open Arena: probably like Freedoom too similar trade dress
- microTD: ProjectABE emulator needs to be checked whether not contaminated with some proprietary firmware/blobs
- Rigs of Rods: can't compile, seems like a huge bloat, will probably reject
- Neverputt: could be libre but is in the same repo as Neverball which has the problematic Octocat, think of a solution
- Neverball commit 77eef90896250837bd2df628cc268b0eb160cb79: no Octocat, has Occulus Rift mascot (TM is okay), check the music and rest of data
- Poweder Toy: compiles, however font may be proprietary, also check if works offline
- Pingus
- The Battle for Wesnoth
- 0 A.D.
- GNU Go: couldn't compile the latest version (syntax errors)
- GNU Robots: looks promising, licensing seems OK, just had issues compiling (libguile)
- FallingTime
- SuperTux: Roboto font is distributed without license (violating its apache license), SuperTux-Medium font doesn't have a license, not sure about licenses of music and sounds, not sure about the bitmap fonts (generated?) in data/images/engine/fonts, files "binreloc.*" have a vague "public domain" statementi (the file seems removed now though), "sqtable.h" has weird notice
- sudokuki: compiles but has some icons and coutnry flags without a license
- MUSoSu: can't compile (deprecated API?)
- Simsu: can't compile (needs newer CMake)
- ksudoku: can't compile (needs newer CMake)
- curseofwar
- Rigs of Rods: complete clasterfuck of bloat, can't even get the correct versions of the required packages
- CAVEZ of PHEAR
- brutalmaze: seems ok but it's in python
- tkinter minesweeper
- Brutalmaze: licensing seems excellent, but can't run it (setup fails)