How to support mods and UGC in your next game

As game studios become increasingly aware of the importance of modding and UGC, there’s one question we’re seeing asked more and more often - just how do you develop an easily moddable game?

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As game studios become increasingly aware of the importance of modding and UGC, there’s one question we’re seeing asked more and more often - just how do you develop an easily moddable game, exactly? While solves the challenges of storage, moderation, and discovery of mods for your game - surprisingly, that’s the easy bit - the real challenge is designing your game in a way that is “mod-friendly,” and considering how your community will create content for your game.

Step 1 - What are mods?

It sounds obvious, but before you can start building mod support into your game, you’ll need to decide which types of mods you want to support. Mods and UGC range from incredibly simple to infinitely complex. This decision largely depends on the kind of game you’re creating, and the tools you’re able to release to your community (more on that later) - some examples of the types of mods you could support are;

  • Paint Jobs / Stickers / ‘Skins’
  • Maps & Environments
  • Vehicle / Character Models
  • Sound / Audio Changes
  • Custom Quests / Scenarios
  • ‘Total Conversions’ (all of the above)

If you’re developing a racing or simulator game, then custom paint schemes, models, and perhaps even audio mods would be fair considerations. First-person shooters and platformers may want to consider custom maps/environments, or custom character models/skins. Complex games such as RPGs may wish to support all of the above. Look at other, similar games that have implemented mods or UGC for inspiration - what types of content do they support, and how are they implemented?

Step 2 - Make your game data accessible

Now you know the types of mods you wish to support, the easiest way to support modders is by making as much of your game’s data accessible as possible;

  • Store game logic in XML, JSON, or a similar easily modifiable format.
  • Create textures in a standard editable format, such as JPG or PNG
  • Place assets such as textures, models and sounds in clearly labelled directories

So for example, if we wanted to create a custom car for a racing simulator, we could simply copy “defaultcar.xml” file and rename it to “modifiedcar.xml” to start creating our custom vehicle. We could then alter parameters within this file, such as changing “max_speed 110” to “max_speed 150” to make our modified car reach a faster top speed. Finally, we could then create a custom paint scheme or livery by changing the car’s texture file in an editing program like Photoshop, and placing this in the relevant directory.

Step 3 - Provide Developer Tools / Documentation

The idea of releasing your in-house development tools can be daunting, but if there’s one important lesson we’ve learned over our 18+ years of experience in modding, it is never to underestimate your community. Modders are incredibly talented and have good technical knowledge - the more access you can provide to your in-house development tools, the more impressive and technically complex mods can be for your game.

Depending on the engine your game is developed with, these development tools may already be publicly available, or third party alternatives may exist. Unreal Engine, for example, allows anyone to freely download and access its development tools through the Epic Games Store. However, you may want to consider any potential licensing restrictions before releasing your development tools.

Forza Horizon 4 Livery Editor
Forza Horizon 4 is an excellent example of an in-game editor, allowing players to create custom liveries quickly and easily

Alternatively, you could consider building simple and accessible in-game tools for creating user-generated content. One example we see more and more often is tools to create custom paint schemes or liveries for vehicles. Two games where you can see this implemented are Forza Horizon 4 and Train Sim World 2, both of which have powerful and easy to use livery editors built into them.

Even if it’s not possible to release your development tools or build in-game alternatives, simply providing documentation on how content for your game is created and implemented is often enough to enable players to start making mods for your game,

Step 4 - Integrate with our UGC backend

Once you’ve tested creating and loading external content within your game, you can start to integrate your game with a UGC integration service like This will make it much easier for players to share, browse and install mods and UGC for your game.

We suggest storing mod content within a separate location, such as a ‘mods’ directory. This will allow you to manage and organise mods much more easily. For example, your game could download our earlier car mod as an archive, ‘,’ which would contain our modified XML and texture file. The game can then look for, and load, external content from this directory. allows your players to upload, tag, discover, and install mods in an intuitive way. The platform is easily integrated into your game thanks to our Rest API, SDKs, and plugins for popular engines including Unity and Unreal. You can learn more about getting started integrating on our documentation pages.


Supporting mods in your game is a fantastic way to extend the shelf-life of your games and compete with larger studios by providing players with a steady stream of fresh, engaging content. Designing your game with mod support in mind can be challenging, but by planning and creating your game with user-generated content in mind, you can easily leverage the passion and creativity of your game’s community to drive growth and success.


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