# Modding Limitations

Because of how the game is implemented and how modding API requires modders to define and register content, many concepts and ideas you have about modding from other games do not carry over well.

This game is implemented with [ECS](/modding-wiki/concepts/technologies-and-tools.md#ecs) so most Object Oriented Programming principles do not apply. As you might have noticed when [trying out the Item Example mod](/modding-wiki/creating-mods/getting-started-modding/testing-the-example-mods.md), if you want to make a tweaked copy of the Copper Sword, you can't just extend the base-game one and change some things. You must create a totally new copper sword from scratch and redefine all of its properties and behaviors on your version.

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## Hard Things to Mod

*Things in this section are possible to mod, but are harder than they seem.*

### Texture Packs

Adding generic texture packs can be rather painful. The issue stems from the fact there is no single place you could replace the textures in. You will have to write specific code for each kind of object.\
\
Very specific texture altering mods however are relatively easy to create.

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## Prohibitively Difficult to Mod

*Things in this section are technically possible to mod, but a massive pain.*

### World Generation

World generation in 1.0 is implemented with GPU shaders. Altering said shader atm is not possible. However custom world generation could theoretically be done after the fact.<br>

If you are interested in this, here's a tip from game developer Fewes:

> What you can likely do right now is use the new API functions `PugWorld.RequestArea` and `PugWorld.RequestPoints`, along with their callbacks `PugWorld.onAreaRequestComplete` and `PugWorld.onPointsRequestComplete` to sample the world generation shader and get data back which you can use however you want.

### Bursted Code

A number of sections of the code are compiled with Burst for performance reasons, making modifying them a massive pain. More info [here](/modding-wiki/concepts/technologies-and-tools.md#burst-compiler).

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## Basically Impossible to Mod

*Limitations in the modding API make it basically impossible to modify these things.* Have you found a way to modify them despite this? [Contribute to the docs](/modding-wiki/how-to-contribute.md) and explain how!

### TODO - Put something here

There are definitely things that are impossible to mod but no one has written them down yet.


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