A small state-of-the-art study on custom engines
July 1, 2025 · View on GitHub
CUSTOM GAME ENGINES: A Small Study
WARNING: Article moved to separate repo to allow users contributions: https://github.com/raysan5/custom_game_engines
A couple of weeks ago I played (and finished) A Plague Tale, a game by Asobo Studio. I was really captivated by the game, not only by the beautiful graphics but also by the story and the locations in the game. I decided to investigate a bit about the game tech and I was surprised to see it was developed with a custom engine by a relatively small studio. I know there are some companies using custom engines but it's very difficult to find a detailed market study with that kind of information curated and updated. So this article.
Nowadays lots of companies choose engines like Unreal or Unity for their games (or that's what lot of people think) because developing a custom AAA-level engine requires lots of resources, so, I decided to list here some of the most popular custom engines with the team-sizes and notable titles released with those engines.
Most of the engines listed here have been developed along the years with multiple iterations and multiple videogames, those engines have gone through several versions or even complete (or semi-complete) rewrites from scratch, with a consequent engine name change. Also, important to note, most of those engines use numerous middleware for specific functionalities (Platform, Physics, Network, Vegetation, UI, Rendering, Audio...).
*NOTE: I tried to be as much accurate as possible with the information about the employees count (I checked the companies websites, Wikipedia or company LinkedIn) but take it with a grain of salt (some employees numbers could not be up to date).
The BIG Companies
*From left to right: Assassin's Creed Odyssey, Final Fantasy XV, Red Dead Redemption 2
Below list is for very big corporations, sometimes with complex corporate structures with several divisions (not only focused on videogames) and various studios/subsidiaries developing games. Some of them work with multiple engines, not only custom ones but also licensed ones.
| Company | Employees | Studios | Engine(s) | Notable Games |
|---|---|---|---|---|
| Activision/Blizzard | ~9200 | ~9 | custom engine(s) | Warcraft series, Diablo series, Starcraft series, Call of Duty series, Overwatch |
| Electronic Arts | ~9300 | ~36 | Frostbite | Star Wars Battlefront II, Anthem, Battlefield 1/V, FIFA 20, Need for Speed series |
| Ubisoft | ~16000 | ~54 | AnvilNext 2.0 | Assassin's Creed series |
| Disrupt engine | Watch Dogs series | |||
| UbiArt Framework | Rayman Legends, Child of Light, Valiant Hearts | |||
| Snowdrop | Tom Clancy's The Division 2, The Settlers | |||
| Dunia (CryEngine-based) | FarCry series | |||
| Silex (Anvil-based) | Ghost Recon Wildlands | |||
| LEAD engine | Tom Clancy's Splinter Cell series | |||
| Dunia-based | The Crew | |||
| Capcom | +2800 | ~15 | MT Framework | Monster Hunter: World |
| RE Engine | Resident Evil 7, Devil May Cry 5, RE2:Remake, RE3:Remake | |||
| Konami | +10000 | ~30 | Fox Engine | Pro Evolution Soccer series, Metal Gear Solid V |
| Square Enix | +4600 | ~18 | Luminous Studio | Final Fantasy XV |
| Nintendo | +6100 | ~8 | custom engine(s) | Zelda: BOTW, Mario Odyssey |
| Riot Games | ~2500 | ~3 | custom engine | League of Legends |
| Rockstar | +2000 | ~9 | RAGE engine | GTA V, Red Dead Redemption 2 |
| CD Projekt | +1100 | ~4 | REDEngine 3 | The Witcher 3 |
| Epic | +1000 | ~11 | Unreal Engine 4 | Fortnite |
Usually those companies invest in custom engines to have full control over the technology and also avoid the revenue cut imposed by the licensed engines. Despite that fact, there are some big companies that in the latest years have chosen Unreal Engine for their productions, the most notable cases are:
- Capcom is using Unreal for the new Street Fighter V title.
- Bandai Namco latest big hits are using Unreal: Jump Force, Dragon Ball Fighter Z, Dragon Ball Z: Kakarot, Tales of Arise.
- Square Enix also moved to Unreal for several new titles: Dragon Quest XI, Kingdom Hearts III, Final Fantasy VII Remake
It's interesting to see that those big three are Japanesse companies, I wonder if that's maybe a market trend for Japan. Also to note, the chinesse holding Tencent owns 40% of Epic Games, I bet it has some influence in the Asian market.
Middle-size Studios
*From left to right: Rise of the Tomb Raider, Uncharted 4, A Plague Tale
Here we have the medium-small companies that decided to create their custom technology for their titles.
The number of employees could be a nice reference to consider because a custom game engine is usually developed in-house (I mean, not outsourced) but note that some of those companies could have a big number of people due to in-house artist/audio teams, while other companies out-source those parts of the development.
It would be really nice to know how many engineers are working on the engine division for each company, I'm sure there would be some big surprises, probably by the low number of engineers working in the engine and tools!
Also interesting to know more info about the tooling included with those engines, it's really difficult to have access to that kind of information. Engines tooling is usually a hidden-secret (beside some GDC presentations or some quick showcase videos).
*From left to right: Horizon Zero Dawn, God of War, Death Stranding
| Company | Employees | Engine | Notable Games |
|---|---|---|---|
| Creative Assembly | +650 | Warscape Engine | Total War series |
| Bungie | ~600 | Tiger Engine | Destiny series |
| Infinity Ward | +500 | IW 7.0 | Call of Duty: Infinite Warfare |
| Eidos-Montréal | ~500 | Dawn Engine (Glacier2-based) | Deus Ex: Mankind Divided |
| Bethesda | ~400 | Creation Engine | Skyrim, Fallout 4, Fallout 76 |
| Valve Corp. | ~360 | Source 2 | Dota 2, Half-Life: Alyx |
| Crystal Dynamics | ~350 | Foundation Engine | Rise/Shadow of the Tomb Raider |
| Avalanche Studios | ~320 | Apex engine | Just Cause series, Renegade Ops, Mad Max, RAGE 2 |
| Naughty Dog | +300 | Naughty Dog Game Engine | Uncharted series, Last of Us |
| Rebellion Developments | ~300 | Asura engine | Alien vs. Predator series, Sniper Elite series |
| Techland | ~300 | Chrome Engine 6 | Dying Light |
| Crytek | ~290 | CryEngine V | The Climb, Hunt:Showdown |
| From Software | +280 | Dark Souls engine | Bloodborne, Dark Souls III, Sekiro |
| Remedy | +250 | Northlight Engine | Quantum Break, Control |
| Guerrilla Games | +250 | Decima | Killzone Shadow Fall, Until Dawn, Horizon Zero Dawn |
| Larian Studios | +250 | Divinity Engine | Divinity series |
| Platinum Games | ~250 | Platinum Engine | NieR Automata, Bayonetta, Vanquish |
| Santa Monica Studio | +200 | custom engine | God Of War series |
| id Software | +200 | idTech 6/7 | Doom, Doom Eternal, Wolfenstein series |
| Sucker Punch | +200 | custom engine | Infamous Second Son, Ghost of Tsushima? |
| Insomniac Games | ~180 | Insomniac Engine | Rachet&Clank series, Marvel's Spider-Man |
| Quantic Dreams | ~180 | custom engine | Detroit: Become Human |
| IO Interactive | ~170 | Glacier2 | Hitman series |
| Asobo Studio | +140 | Zouna | A Plague Tale |
| Ready At Dawn | ~120 | custom engine | The Order: 1886, Lone Echo |
| Mercury Steam | ~110 | custom engine | Spacelords, Castlevania:Lords of Shadow series |
| Monolith Productions | +100 | LithTech | F.E.A.R. series, Condemned series, Shadow of Mordor/War |
| 11 Bit Studios | ~100 | Liquid Engine | Frostpunk |
| Frozenbyte | ~100 | Storm3D | Trine series, Shadowgrounds |
| Kylotonn | ~100 | KtEngine | WRC series, TT Isle of Man series, V-Rally 4 |
| TaleWorlds Entertainment | ~100 | custom engine | Mount & Blade II: Bannerlord |
| Daedalic Entertainment | ~90 | Visionaire Studio | The Whispered World, Deponia series |
| Media Molecule | ~80 | Bubblebath Engine | Dreams |
| Paradox Development Studio | ~80 | Clausewitz Engine | Imperator: Rome, Stellaris, Europa Universalis series |
| Deck13 | ~70 | Fledge | Lords of the Fallen, The Surge, The Surge 2, Atlas Fallen |
| Nihon Falcom | ~60 | Yamaneko Engine | Ys VII, Ys VIII, Ys IX |
| Croteam | +40 | Serious Engine | The Talos Principle, Serious Sam series |
Some observations from this list:
- Rise of the Tomb Raider lists only 10 programmers working on Foundation engine in the credits, probably a good reference number to get an idea of the people working on the core engine.
- Kojima Productions use Decima engine, developed by Guerrilla Games, for Death Stranding, previously they used Fox Engine for Metal Gear Solid V.
- Media Molecule latest game/engine (Dreams) seems to have been developed by only ~15 coders, amazing!
- Companies targeting one single platform, usually have less restrictions and can push the limits of that platform. Unfortunately, that's a luxury that most companies can not afford.
- Asobo Studio, the company that originated this market study is not that small... but, like other companies, they seem to work in multiple titles in parallel.
- Very nice to see that some of the engines have entries in the Wikipedia with some details and titles released, it should be a must.
Small-size Studios (Indie Studios)
*From left to right: The Witness, No Man's Sky, X-Morph Defense
Here we have some really small studios that also choose to develop a custom engine for their games. Note that most of those engines rely on other libraries/frameworks for certain parts of the game, the common choices we find are SDL (cross-platform graphics/input), OGRE (rendering engine), MonoGame (cross-platform game framework, also relyes on SDL, SharpDX, OpenTK, OpenAL-Soft...).
One question many people could ask is, what parts of the engine are actually coded by the developers? Well, it depends, but usually coders take care of the screen-manager, entities-manager and content-manager as well as the wrappers/interfaces to the external libraries.
Second question, what parts of the engine usually rely on external libraries/middleware? It also depends on the company resources but usually audio-system, physics, rendering, networking, ui-system, terrain-system, vegetation-system and some other pieces.
*From left to right: Factorio, Thimbleweed Park, Owlboy
On the following list (and the next one below) I added the publishing date (only +2012) and the link to Steam for all the games... there are not many games with custom engine from small studios out there and I think they deserve to be recognized and supported.
Some observations from this list:
- Nicolas Cannasse, co-founder of Shiro Games, is the the developer of Haxe programming language and Heaps engine, used by Motion Twin for Dead Cells (2017).
- Hello Games is a very small studio considering the size of No Man's Sky and that they use a custom engine. Really impressive!
- Runic Games was dissolved in November 2017, the founders created Double Damage, now they are working on Echtra Games on Torchlight III.
- Rodrigo Braz Monteiro, Chucklefish CTO, is the person in charge of Halley engine, actually the engine is open-source!
- In most of those studios the people in charge of creating the game engine it's only 1-3 persons!
- Lo-fi Games was a one-man team (Chris Hunt) for more than 6 years!
- Some of the games in this list took +5 years of development!
- Not many games... a couple of hits per year...
One-man custom engines
*From left to right: Stardew Valley, ScourgeBringer, Eagle Island
Finally, the list of the heroes.
Games developed by 1-2 people with custom game engines, engines mostly coded by one person! Respect.
Creating an engine and a game from scratch to the point of publishing it is an extraordinary accomplishment, not many people in the world is ready for that. Almost all of them are 2D games, usually with very small budgets and developed along multiple years. Congratulations to the developers!
*From left to right: Axiom Verge, Ghost 1.0, Remnants of Naezith
| Company/Developer | People | Engine | Notable Game(s) |
|---|---|---|---|
| Lizardcube (Ben Fiquet and Omar Cornut) | 2 | custom engine | Wonder Boy: The Dragon's Trap (2017) |
| Guard Crush Games (Jordi Asensio and Cyrille Lagarigue) | 2 | MonoGame-based | Streets of Rage 4 |
| Pocketwatch Games (Andy Schatz) | 2? | MonoGame-based | Tooth and Tail (2017) |
| Justin Ma and Matthew Davis | 2 | custom engine | FTL: Faster Than Light (2012) |
| Ed Key and David Kanaga | 2 | custom engine | Proteus (2013) |
| Mountain Sheep | 2 | custom engine | Hardland (2019) |
| Flying Oak Games (Thomas Altenburger and Florian Hurtaut) | 2 | MonoGame-based | Neuro Voider (2016), ScourgeBringer(2020) |
| Marc Flury and Brian Gibson | 2 | custom engine | Thumper (2016) |
| Jochum Skoglund and Niklas Myrberg | 2 | custom engine | Heroes of Hammerwatch (2018), Hammerwatch (2013) |
| Villa Gorilla (Jens Andersson and Mattias Snygg) | 2 | custom engine | Yoku's Island Express (2018) |
| Two Mammoths (Piotr Turecki and Marcin Turecki) | 2 | custom engine | Archaica: The Path of Light (2017) |
| Bare Mettle Entertainment (Madoc Evans) | 1? | custom engine | Exanima (2015) |
| Lucas Pope | 1 | OpenFL-based | Papers, Please (2013) |
| Terry Cavanagh | 1 | custom engine | Super Hexagon (2012) |
| Francisco Tellez | 1 | SDL-based | Ghost 1.0 (2016), UnEpic (2014) |
| Grid Sage Games (Josh Ge) | 1 | SDL-based | Cogmind (2017) |
| Luke Hodorowicz | 1 | custom engine | Banished (2014) |
| Thomas Happ | 1 (5 years) | MonoGame-based | Axiom Verge (2015) |
| James Silva | 1 | MonoGame-based | Salt and Sanctuary (2016) |
| Eric Barone | 1 (4 years) | MonoGame-based | Stardew Valley (2016) |
| Tolga Ay | 1 | SFML-based | Remnant of Naezith (2018) |
| Nick Gregory | 1 (5 years) | MonoGame-based | Eagle Island (2019) |
| bitBull Ltd. (James Closs) | 1 (4 years) | MonoGame-based | Jetboard Joust (2020) |
| Benjamin Porter | 1 (8 years) | SFML-based | MoonQuest (2020) |
| Randall Foster | 1 (7 years) | custom engine | Kid Baby: Starchild (2019) |
| Dennis Gustafsson | 1 | custom engine | Teardown (2020) |
| Christian Whitehead | 1 | Star Engine | Sonic Mania (2017) |
| Positech Games (Cliff Harris) | 1 | custom engine | Production Line (2019), Democracy 3 (2013), Gratuitous Space Battles (2015) |
| Frank Lucas | 1 | custom engine | Angeldust (2019) |
| Zachtronics (Zach Barth) | 1 | custom engine | MOLEK-SYNTEZ (2019), EXAPUNKS (2018), SHENZHEN I/O (2016), Opus Magnum (2017) |
| Lunar Ray Games (Bodie Lee) | 1 | custom engine | Timespinner (2018) |
| sebagamesdev | 1 | custom engine | Fight And Rage (2017) |
| Loïc Dansart | 1 | custom engine | Melody's Escape (2016) |
Some observations from this list:
- Some of those teams are formed by 1-2 people but probably grew at some point and/or outsourced some parts of the development (art, audio...). Usually the publisher also helps with some resources (localization, marketing...).
- Omar Cornut from Lizardcube is the main programmer for Wonder Boy: The Dragon's Trap engine and also the developer of Dear ImGui, a free and open-source immediate-mode gui library used by lots of AAA custom engines.
- Ben Fiquet from Lizardcube is also the main artist for Streets of Rage 4, the custom engine of Guard Crush Games is written by Cyrille Lagarigue.
- Marc Flury programmed Thumper game engine rejecting the OOP paradigm in favor of a procedural programming approach.
- Christian Whitehead is the creator of Star Engine used in Sonic Mania but Headcannon (Simon Thomley) and PagodaWest Games (Jared Kasl and Tom Fry) were also involved in the development of the game.
- Some of the games in this list took +5 years of development!
- Not many games... a couple of hits per year...
There are some other remarkable games using custom engines that worth mentioning: Minecraft (2011), Braid (2009), Super Meat Boy (2010), Terraria (2011), Dustforce (2012), Sword and Sorcery EP (2012), FEZ (2013), Dust: An Elysian Tail (2013), Rogue Legacy (2013), Dyad (2012), SpaceChem (2013), Darkest Dungeon (2016), Scrap Mechanic (2016), Battle Brothers (2015), Renowned Explorers (2015), Yuppie Psycho (2019), Surviving Mars (2018), The End Is Nigh (2017), The Binding of Isaac: Afterbirth (2017), The Binding of Isaac: Rebirth (2014), BattleBlock Theater (2013), Full Metal Furies (2017), Binding of Isaac (2011), Rusted Warfare (2017).
Conclusions
I'll start saying I'm biased, I'm really passionate about videogames-making technologies and I admire custom engines and game-making tools. I also contributed to custom engines ecosystem with my grain of salt: raylib and several game-making tools. I prefer a custom engine over a licensed one, I consider that the extra amount of effort put into the product usually translates into some specific great mechanic or some amazing in-game details.
Said that, I must admit that creating a custom engine is a big endeavour and not many people/companies are ready for that. I recognize Unity (and Unreal to less extend) have really democratized videogames development, lots of small-medium size companies can use Unity today to develop games quickly, sometimes, with very low budgets... But, still, lots of big companies prefer to rely on their own custom technologies.
From my gamedev-teacher perspective, I think students should learn how engines work internally with as much detail as possible. Relying only on engines like Unity/Unreal for education to allow students develop eye-candy project in short-time is not the way to go. At the end of the day, someone has to write the engine and the tools!
NOTE: Feedback and improvements are welcome! :)