The best open-source games you know

Shattered Pixel Dungeon ! And its origin, Pixel Dungeon.

A really nice rogue-like, among the best Android games I know, it’s still fun after all those years and very actively developed !

Great classical roguelike
Would love to checkout the code for this thanks for the suggestion

Mindustry is a really fun automation/tower defense game

Second Mindustry, I played it up once and it was great. Basically Factorio for phones.
- thirded. played it years ago and got into it again recently. you should check it out again, there's a lot of new stuff they've added.

Did you guys tried Endless sky? Awesome game if you love space

And minetest+mineclone2 is pretty good if you want to play minecraft but don't have the license
- Thank you for this! I have already logged hours playing with my kid since seeing your suggestion. We have only played mineclone2 so far. I will look into veloren next.
- Minetest in general has such a good mod selection it’s insane! My siblings and I never fail to have a good time goofing around with the plugins people have created.
Such a great game.
Came here to mention Endless Sky. Great game!
Don't be misled if you were a fan of the old Mac games Escape Velocity or EV:Nova, Endless Sky is inspired by/derivative of EV but is not the same and you'll (well, I did) find out the hard way that the old strategies don't carry over.
- I grew up playing the EV series and I love Endless Sky. Is there something about the clone that you don't like? I can't thing of a change that I dislike. For example, fleet management is improved. Being able to dock your various ships and escorts is pretty cool.
I recently got into that game quite a bit. Playing it on steam. Just the other day I discovered I can board pirate ships and kill the crew to claim the ship as my own. That has been a significant power boost for me and really unlocked the game.
Even before that I was having fun trying to survive with limited power while still exploring the world

Beyond All Reason is AMAZING. I can't say enough about it. Its my favourite game, and totally annihilates (!) the competition.

I don't really like this type of games but the game looks pretty cool
- Yeah its a specific type of person that would enjoy it, perhaps a Factorio/Factory Must Grow genre mixed with small scale RTS.
  Still, playing 20v20 games are incredible.
Had too scroll way too far for BAR. It’s amazing!
- Its also gone gangbusters over the past few months, unsure why. Hundreds of concurrent players at any time which is pretty amazing.
Also ZeroK, on the same springRTS engine
- Zero K is also great, but they've changed the gameplay a lot from the original TA

Cataclysm DDA Is THE open world zombie survival experience. So long as you like obtuse roguelikes with nearly no graphics.

Although Im obviously biased what with being a dev and all.

CDDA is mind bogglingly cool. I play a weekend of it every few months. I know it won't ever happen, but if it got the Dwarf Fortress Steam treatment one day, it could be the last game I ever bought and I'd be happy.
- I'll just leave this here ;) https://store.steampowered.com/app/2330750/Cataclysm_Dark_Days_Ahead/
- Are you just referring to wanting the game to be on Steam? Because it is.

OpenTTD is good

I get the itch for this game every year or so and everytime its amazing
I love that game. I've put so many hours into it

Beyond All Reason

https://www.beyondallreason.info/

It a grand scale RTS game with robots and insects loosely inspired by Total Annihilation.

Holy shit, this looks awesome! Maybe I can scratch that TA itch - thanks!
- I've really enjoyed it.
  If you like Supreme Commander, you will be sooo very happy with this.

Battle of Wesnoth. Haven't played it in a while, but I remember spending hours playing that at one point.

And there are so many campaigns, it is incredible.

Have not seen anyone mention one of the best rogue like games out there, Tales of Maj'Eyal

https://te4.org

Base game is free to download and play from their website. Massive world, tons of loot, an incredible number of classes and abilities to combine, it's such a fantastic game that also has native Linux support.

Several, but my number one fav so far is Battle for Wesnoth. An old school hex tile turn based strategy game. Like something out of the 90's or very early 2000's.

Great art, awesome music, solid gameplay, and runs on a potato.

My best friend and I play it whenever we want a casual chill, play n' chat gaming session.

It runs great on the Steam Deck too with a few interface tweaks.

It is from the 2000s. Its first release was in 2005.
- I feel old now, thanks (:
I've installed wesnoth on at least 10 different computers and laptops over the years. My son's enjoying it now, what a classic
- Glad he's having fun with it! I hope to share it with my kids one day. :)
Battle For Wesnoth is such a nostalgia hit. Great game too.
- Totally!

Cataclysm Dark Days Ahead has been mentioned so I'll add OpenMW to the thread. It's a open source engine rewrite of Morrowind and requires the base game to run Morrowind but it has the potential to be used to create new games and the devs are looking to expand it to allow the creation of ARPGs as well.

Another worthy mention is Endless Sky, it's an open source game inspired by the classic space trading and combat game Escape Velocity.

Since you mentioned OpenMW I thought I should mention Daggerfall Unity. It's an rewrite of Daggerfall using the Unity engine, also requiring the original files. The best thing about is that the developers have made it easily moddable and a very healthy modding community has sprung up for it, some of which really make the game feel like what the original developers were going for but had to deal with the technical limitations of the time.
Endless Sky was surprisingly addictive to me, it really scratched the exploration itch. Sadly I played through most content at some point, so now I'm waiting for there to be enough new stuff for me to play again. I really enjoyed it, including the stories and lore and universe!
- I also played through most of the content at some point, but when they eventually updated with new content I couldn't get back into it. Maybe I should try again because that was such a fun game.

Veloren is inspired by games such as Cube World, Legend of Zelda: Breath of the Wild, Dwarf Fortress and Minecraft.

You can play single player or multi-player, standalone or use an online server, or even host your own server in a Docker container, or on a Raspberry Pi. Plenty of options!

You start by creating your character, you can collect items for your inventory, you can craft items, there are weapons and combat, you develop skills, can tame creatures, you can trade with merchants, you can socialise, and lost more. There is no single, specific goal or focus, and the idea is to keep exploring and have adventures.

The game is community driven and actually updates quite regularly.

It is clearly no clone of Minecraft. It is fun and adventure!

See https://veloren.net/

Totally agree, one of the best open-source games ever

If you like RTS games similar to Total Annihilation, you should definitely check out Beyond All Reason, it's gorgeous and fun: https://www.beyondallreason.info/

Another supcom similar is zero-k. Didn't know there were so many open source options! Available on steam or at https://zero-k.info/
- ZeroK uses the same engine as BAR, my game, and quite a few others. 😋 And yes, definitely should check out ZK, it's a mature project with a nice community and awesome devs.
  Recoil is pretty much the only foss engine purpose built for modern rts games of all types.
Now there’s a name I haven’t heard in a while. I sank way too many hours into this (started off as a TA clone but branched off into other game modes too) a decade or two ago, and it looks like it’s still going.
https://springrts.com/
- Spring is dead. The fork Recoil is going strong and fast. :-)
This looks really cool. SupCom wasn't quite the same for me so I'll have to check this out.

OpenRCT if you're counting that style of open source game

I thought you needed to bring your own assets for that game
- You do, but the game logic itself is all OSS. It just requires you to buy the games in order to load the assets and scenarios. IMO it's a great open source achievement even if it isn't 100% pure open source. There have even been community additions like mods and custom ride types that really make the game even cooler.

Cube 2 Sauerbraten is pretty good! Free arena shooter with built-in level editor

The original Cube is also fun, at least as a singleplayer game and comes with a lot of SP maps. The SPMP (or MPSP, i don't remember :-P) mode also allows playing the MP maps with randomly spawned bots.
The AssaultCube fork adds more realistic environments (relatively to the original game anyway), though it is fully MP oriented. But you can still play with bots.
- There are still people playing AssaultCube?

I will say that 0 A.D. and veloren are my favourites!

CataclysmDDA is an amazing open source roguelike. Has a bunch of tilesets if you don't like ASCII

Also most og roguelikes are open source which is great!
What other game you can play as neckbeard otaku on a quest to become a real catgirl in the world infested with zombies and whatnot? God I love Cata

Oof, I have a huge boner for roguelikes, and most of them are open source. My biggest time sink is still Dungeon Crawl Stone Soup, playable online at https://crawl.develz.org/

This one is great, I have spent many hours on it!

https://github.com/open-duelyst/duelyst

Duelyst was a very popular online card game that shutdown around 3 years ago. The developers have recently released it into the public domain (via CC0 license).

You can completely selfhost a private instance (repo has a good straight forward guide)

There is a public instance available to try https://duelyst.org/. Though it might be pretty barren.

There is also a closed fork which should have a more active userbase https://duelyst2.com/, the game rules are a little different (draw 2 vs draw1), but should have more users to get a feeling for the game.

The game in a nutshell is basically Hearthstone on a chessboard. It’s very fun and approachable and in my opinion one of the best cardgames right next to MagicTCG :). Hopefully the community for it will grow more and we can have a sort of second renaissance for it :)

I seriously think that every online only game should have to make the server assets public if they've abandoned it longer than 10 years. So many good games are just lost to time.
You have my attention

I haven't seen any incremental games get posted. They aren't exactly traditional games, but so many of them are open source like Antimatter Dimensions or Synergism. Bitburner is a unique one as an incremental hacking sim, since it relies on actual scripting to grow and automate tasks.

Mindustry is an awesome strategy game that combines Factorio with tower defense.

Sonic Robo Blast 2 Kart (ridiculous name I know) is one of the most underrated games ever. It's a super polished, high quality Kart game with an insane amount of mods and maps. The online isn't that populated but the singleplayer time trial is TONS of fun. If you like hunting for medals, it can be a pretty deep rabbit hole. There's a sequel in development but no release date.

GzDoom is the most popular Doom source port and there's a practically infinite amount of user generated content. If you don't know where to start I highly recommend Doom: The Golden Souls Remastered and Castlevania: Simon's Destiny. They're good enough to be premium games.

Mindustry is the bomb

Warzone 2100 is an RTS from 1999 that went open source at some point and can be played on just about anything. It's unit design functionality is really cool and I'm a sucker for post-apocalyptic worlds.

Unciv

Dungeon Crawl Stone Soup

Some great games already on here, but wanted to share some love for VVVVVV which released its source a few years ago.

There's not a whole lot of activity around it these days, but Zelda Classic is an engine for Zelda 1 with a number of additions and improvements, that allows for custom maps, tilesets, scripts, items, enemies, etc. etc.

I've whiled away an unreasonable amount of time on quests that are on par mechanically and quality-wise with Link's Awakening and the Oracle games. Shame I can't get the tarball to work properly on Steam Deck, it's a great fit for that hardware.

OpenRA has open source slightly modernized versions of Red Alert, Tiberian Dawn and Dune 2000. There's also Tiberian Sun-like and Red Alert 2 mods for it :)

Dungeon Crawl Stone Soup Love this traditional roguelike!

Tux Racer. Hands down.

I still jump into Quake 3 DeFRaG sometimes. It's a movement game, probably one of the earliest examples of a game / mod where the primary focus is on movement as opposed to shooting or some other mechanic. Its mere existence heavily inspired a lot of source engine movement communities like surf, bhop, kz, etc.

Here's a good video showcasing what DeFRaG movement looks like. Each map is ran on two variations of the physics. One is VQ3 (vanilla quake 3) and CPM (Challenge ProMode Arena, which was originally a Quake 3 mod that heavily altered the physics to make it more fun for professional play). While there's no one DeFRaG game, there's a shitload of open source mods to the original game that modify the physics and allow you to join servers running DeFRaG maps. Some of them even hook up to the online database allowing you to register times without recording your runs and submitting them the traditional way. There's usually a new open source defrag mod rolling out every 3 years or so, and each one builds upon the successes of the previous one. The one I currently use is iDFe which I think came out around 2018 or so? I'm pretty sure there's a new one, and there are other games in the works in both modified Source Engine and Unreal Engine 4 that are looking to emulate the VQ3 and CPM physics for modern engines.

The community is pretty dead, but it rises from the ashes every few years for DFWC (the video I linked above was DFWC 2017). You can always play any one of the thousands of maps in singleplayer too.

That's amazing. It reminds met of the "hardjump" maps that used to be hosted on Splinter Cell: Chaos Theory servers. It was just an insanely big obstacle course.
- You'll find all sorts of maps in defrag. Lots of them are "race" style maps, but some are obstacle courses, others are puzzle maps, there's even a few with stories. Lots of people also like to race on the official maps, like on CTF maps showing how fast they can capture a flag given unlimited ammo and time to practice. I even saw a horror map once. They are all anchored by the whole "go fast and get a good time" thing though.
  You might also like this video, which is of the map "Final Torture," a compilation map of 5 "torture" maps, where if you fall at any point in the map you have to restart the entire thing. Only two people have ever completed it iirc.

Here's a good start.

Fillets-ng (sokoban puzzler)

Simon Tatham’s Portable Puzzle Collection (sgt-puzzles)

Sauerbraten (FPS)

0 A.D. (RTS)

Holotz Castle (platformer)

Xmoto (motorbike trials riding)

Kobodeluxe (shmup)

Neverputt (minigolf)

Classic roguelikes have the most longetivity for me. Crawl, Brogue, Nethack.

ADOM was always my favourite, but Dungeon Crawl: Stone Soup is my go-to these days.
Shattered Pixel Dungeon on android is also fantastic and has wonderful touch screen controls.
This. I just keep coming back to nethack.

Pixel Dungeon! Great rogue like mobile game

Shattered Pixel Dungeon takes the original (PD by Watabout) to a next level. Check it out!

If reverse-engineered Nintendo games count, then Super Mario 64 and Pokemon Emerald whose engine is technically open source.

EDIT: Minecraft Beta 1.7.3 has been reverse engineered multiple times too.

Reverse engineered N64 games? Can you provide a link?
- https://github.com/n64decomp/sm64/blob/

I really enjoy Thrive, it's basically a modern and more scientifically accurate Spore!

Ooh, neat! Thanks for the recommendation!

Warzone 2100. It reminds me of the older Command & Conquer games with a ton of upgrades and customization for your units.

Doom :)

Supertuxkart 2

absolutely! I'm really impressed with how far it's come along.

Puzzle

Rocks'n'Diamonds - Digging for diamonds while avoiding boulders and enemies
Enigma | github - Marble puzzles (and much more) inspired by the classic game Oxyd
GNU Robbo - Solve rooms (puzzles) with your robot

Space

Oolite | github - an open-world space opera (inspired by classic game Elite)
Kobo Deluxe - 2D scrolling space shooter, destroy star bases with your ship
Open Tyrian - Arcade-style vertical scrolling shooter

Open Tyrian is great, the original is always free on GOG Tyrian 2000

OpenTTD is my drug. I'm addicted

Came here to comment that game. It's so good, it just brings me back to when I was a kid and played the older, non-Open version, on my first PC. Today, when I actually am old enough to understand all of the mechanics and complexities, it's a very fun and engaging game that you can sit down with a hot mug of tea, and just let it take half of your day away without noticing. It's great!
Now see ive tried that game and it didn't quite stick it's claws into me. What about it is addicting to you?

Teeworlds. There are some great community made modes for it like FNG and DDrace. Be sure to download it from ddnet.tw to access to extra features created by the community.

I didn't know DDrace was open source, that's cool. It's a really cool game highly recommend it!

I like supertuxkart and minetest

Seconding Minetest. It's a lot of fun just to poke around the forums and work on my own little projects and additions with minimal actual programming skill required

There are a few open source game projects I follow. I suppose the most famous one is the Freespace 2 source code project. Although it didn't start open source, the original devs open-sourced it later. It has great support, and a great modding launcher called Knossos. To play the game, even with the source code, you either need the original disks or a copy of the installer from GoG, but it's really cheap. Getting it working on Windows is pretty easy, but Linux is only slightly more complicated. (Fortunately, there's a new launcher that makes it way easier).

If you're interested, let me know.

OpenRCT2, eDuke32, the various Doom and Quake games

Also ScummVM is open source and supports many games

Yo I wasn't expecting to randomly see you here, great work on the Deus Ex randomizer!
- Thanks! Yeah I'm really loving Lemmy so far, btw we do have a Deus Ex community
  https://lemmy.ml/c/deus_ex
  (Unfortunately lemmy.ml has been pretty unstable, might have to wait for it to come back before you can subscribe)

Shapez is a fairly relaxing factory game. Pretty minimalistic style but easy to lose tons of time to if you aren't careful.

Don't think that's an open source game bud
- Sure it is, in fact running it yourself is one of the ways to unlock the full game content.

Veloren

Not quite what you are asking for, but here's a list of source ports of commercial games, most of which have Linux ports.

Oh and I'll single out The Ur-Quan Masters as an older source port of Star Control II. Old enough that the port itself is nostalgic for me, although it's still being updated by the looks of it.

0 A.D. is the closest experience to Empire Earth I've had on the FOSS side. Great fun!

Hum more Age of Empire than Empire Earth I think

For me it's CDDA, a quite realistic and deep apocalyptic survival game with very frequent updates(on the experimental branch)

Simutrans. It's old but really good. It's really easy to lose 10h or so in it before you notice the time.

Reminds me of OpenTTD. I love the classics
I remember playing this with a friend. We modified the source code to allow us to use the fast-forward functionality in an online mutiplayer game. Once we figured out how to make proper grade-separated junctions, it ended up becoming quite a tedium. I wish Transport Fever had a multiplayer mode.

Tremulous - The game was so fun back then (like 10 years ago ?) I guess it's a dead game now.

Pokemon Emerald 😉

Xonotic is a fun quake-like shooter. Highly recommend.

osu!lazer

Xonotic. I even got a server in my region!

Endgame: Singularity is a fun (and sometimes very frustrating) small strategy game worth checking out.

The Dark Mod is basically Thief but really well done with a solid amount of (fan) missions to choose from. Speaking of I should play some of it again.

0.A.D., Veloren and Xonotic are my favorites. Also Sonic Robo Blast 2 is freaking awesome

Cataclysm: Dark Days Ahead

I am a big fan of Neverball

0 A.D. and Beyond All Reasons for me ^^

If you didn't already suggest it, I would have suggested Veloren!

Yep, what's promising about Veloren is I feel like everyone had a pretty cohesive idea of what Cube World was "going to be". It's pretty hard to disappoint a community when the developers are the community.

Battle for Wesnoth is a personal favorite of mine that I haven't seen mentioned elsewhere in the thread. It's a pixel art, hex-grid turn based strategy game with fantasy armies. It's mixed with mild RPG elements, and there's tons and tons of campaigns and fanmade content accessible directly through a mod browser in game.
The other games I enjoy that I see being mentioned here are in the same vein. BAR, Warzone 2100, OpenTTD. And the open mods based on the STALKER engine, like Anomaly. I love those.

Unciv! Remake of civV for desktop and Android.

OpenTTD is a great open source clone of the transport tycoon game. And boohu is an awesome ASCII coffeebreak roguelike.

Oh~ this game looks like someone was really disappoined by how cube worlds dev killed the release on steam i guess. Thanks for that, i will check it out. tl;dr Game was gutted on steam release but so much more was already done, promised and/or teased.

I'm surprised to not see Flare RPG mentioned. It's nothing groundbreaking on its own, but it's actually got two nicely fleshed out campaigns, and tooling for people to make new ones. It's a nice, fun, FOSS single-player RPG, and it's great if you want that old fashioned Diablo feel.

Another vote for Endless Sky here as well, it's just excellent, and surprisingly expansive.

Minetest!

https://www.minetest.net/

I've had a ton of fun in Red Eclipse over the years.

I made one! It's a solitaire-like but with some new mechanics, and fairly polished and balanced at this point. You can find it on itch and on the play store. Here's the source.

InfraArcana was a little bit tough but is a very good roguelike

How does it compare to something like Brogue?
- I haven't played Brogue but in nutshell IA is a proper roguelike and somehow manages to create the atmosphere of being alone in the dark in a mansion full of acolytes and worse

Only one that comes to mind is Lugaru. The creator had this weird legal battle where someone stole the game, ported it to iOS, and the thief claimed because it was open source he was allowed to sell it.

I'd say Pokemon Infinite Fusion. It's written in Rails and the artwork is done by the community

- It's a Pokemon clone of FireRed/LeafGreen I think that lets you fuse Pokemon in pairs. You can have a Pikachu/Chikorita if you want and each one will evolve independently, so you essentially have 12 pokemon in your party. The fun part is the fusion art that sometimes has some hilarious and cool results. It also has its own adjustments so that it feels less grindy so you can get through both the Johto and Kanto regions easily.
  Here's a link to the wiki

classicube is pretty cool, open source Minecraft classic-like game (so, no crafting or survival aspects, limited world sizes)

Aside from the other choices already mentioned (especially Doom stuff, FreeDoom ftw) any of the free games derived from the S.T.A.L.K.E.R. games and early builds, mostly Anomaly and Lost Alpha. There are also a few stabilized versions of the Build 1935 alpha out there which are worth playing and probably a bit more approachable for most people.

Surprised it's not mentioned here, but Bzflag.

Super fun tank shooter game that doesn't take much to run, and reminds me of a cross between the very old bolo game and Mario kart's battle mode.

Thanks for the Veloren recommendation, I liked Cube World, it just didn't work out well.

It's old but I always really liked WARSAW it was/is a quake3 port but with more cartoony outline graphics similar to Borderlands style.

Terminal games:

Adventure - A classic adventure game. (In the BSDGames package) Hack - The game that inspired NetHack. (In the BSDGames package) Greed - A game where you go through a number field, eating the numbers. It's hard to explain but very fun. Rouge - It's nice to go back to the classics. I like Hack a bit more though.

Non-Terminal Games:

Secret Maryo Chronicles - It's like Super Mario Bros. Alien Arena - Kind of like natural selection. Urban Terror - Kind of like Counter-Strike Warsow - Kind of like Quake. Xonotic - Like Quake again.

I think that's all I played back in the day.

Pokemon Auto Chess. Literally what the name implies, a Pokemon auto battler game. Honestly it's really well-polished for something only a couple of people are working on (aside from commissioned sprite artists) and has an active community to go with it.

Cockatrice for playing TCGs / CCGs online.

shattered pixel dungeon

+1. I probably spent 100s of hours on this game across commutes

Arguable if you can call it a game or not, but there is Overte. It is an open-source social VR platform. (without crypto so please no pitchforks)

As one of its developers I might be biased, but I wouldn't be one of the developers if I didn't honestly believe in the project.

Wow thats amazing!