I just played Xonotic for the first time ever and now I'm interested. I like a game I can be sure isn't selling my data to China.
I would personally like an RTS, a game in whatever genre Stick Fight falls under, and sandboxes, although any genre is fine. I don't contribute code, but I'm pretty good at finding bugs, etc. and get a few laughs out of people on the forums with my jokes.
Games in early development preferable, mostly for the active community these tend to have, so I can share less formal work with them and join their Matrix.org room or something
0 A.D. is a modern take on Age of Empires.
Other than that I'm aware of a bunch of projects that reverse-engineer engines of older games. They're FOSS but you need to buy the original game in order to obtain actual game data (models, textures, maps...). These include OpenRCT2 (Rollercoaster Tycoon), OpenMW (TES3: Morrowind), and Freespace 2. I just noticed that Freespace even has standalone games now, so you can play something without buying the commercial game, but this is the first time I'm seeing that so no idea about the quality.
The only open source games that come to mind are OpenTTD (a clone of Transport Tycoon Deluxe), FreeCiv (clone of Civilization) and FreeCol (clone of Colonization).
Dwarf Fortress isn’t open source but they sure as hell aren’t selling your data. It’s probably my favorite game of all time, but it’s not exactly easy to dive into.
IIRC the creator claimed it will be made open source when he dies, provided there isn't evidence of foul play. Great game either way.
I wonder if that will still be the case now that the game is pending a Steam release. The free version will continue onward, so presumably that will become FOSS someday.
Based DF developer.
any open source game would be hijacked by sjws and turned into a shit show especially if trannies sre involved.
Any project that goes to shit (dev drama, no new updates etc) gets forked into a new project. It has already happened many times over.
Super Tux Kart. Yes, that Tux.
Open Arena comes to mind. Basically a Quake clone
Warzone 2100 is an open source RTS I used to play.
The roguelike genre is almost entirely FOSS, with my favorite being DCSS and Brogue. For RTS games you have OpenTA and Widelands.
Liero - a real time version of Worms
Scorched 3D - Full 3D version of Scorched Earth with fully destructible terrain
Vega Strike - open world space flight sim
Soldat - 2D shooter based on the Quake 1 source code. Now on Steam
Cataclysm: Dark Days Ahead - turn based post apocalyptic roguelike
Warsow - FPS, based off of the Quake 2 Engine
WG Realms 2 - glorious mashup of Doom and Duke3D
OpenXCOM maybe