How to Mod Almost Any Game With Claude Code
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How to Mod Almost Any Game With Claude Code

Ethan Cole 30.09.2026 16:10 0
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After seeing videos of Minecraft inside Elden Ring, skateboarding in Modern Warfare 2, robotaxis in Age of Empires 2, and other forms of digital insanity, it's easy to assume Anthropic has released a button that lets you break any game however you want. Reality is a little less magical, but arguably even more interesting. Claude Code really can be turned into an almost autonomous modding workshop: give it access to the project files, connect plugins and skills for a specific engine, teach it to work with a decompiler, add fal.ai for generating sprites, textures, 3D models, and sounds, then let the agent build the project, run tests, and investigate its own errors. What doesn't exist, at least for now, is an official Anthropic plugin with a big Add Minecraft to Elden Ring button.In this guide, we'll go over a practical setup as of September 2026: how to install Claude Code, which plugins and tools are useful for modding, which games are easiest to start with, how to give the AI proper access to a project, and what the full workflow looks like from the sentence I want a new item to a working mod. And yes, knowing how to code manually is still useful. You just have an extremely fast partner now, one that can write overnight the amount of code a normal person would usually postpone until next year.

What Actually Happened and Where Is That Modding Plugin?

First, an important clarification, because rumors are already starting to grow around the latest videos. There really are impressive projects being built with Claude Code. New modders are decompiling older games, moving mechanics between completely different projects, and creating mods almost entirely through conversations with an AI. Developer Maurice Heumann, for example, described using Claude Code and several parallel agents to decompile Call of Duty: Modern Warfare 2, while separate open-source projects already let Claude connect to Ghidra, inspect binaries, and gradually reconstruct game functions.That doesn't mean there is a universal Claude Modding Plugin that understands every game the moment you install it. In practice, the setup consists of several components: Claude Code itself, project instructions in CLAUDE.md or SKILL.md, decompilers and MCP servers, engine-specific tools, the build system, and optional external services for asset generation. That's why one developer can move a mechanic into an old Call of Duty overnight while another spends three days figuring out why a Unity door keeps opening into a wall. AI can accelerate the work enormously, but the internal structure of each individual game still matters.A good real-world example is Accessibility Mod Template. It's a ready-made Claude Code template built around actual game modding. The project stores decompiled materials separately, makes the agent document the game's API, writes the mod code, builds it, and helps diagnose errors. Another example is Skyrim-Claude Code Modder's Toolkit, which can turn an installed copy of Skyrim SE/AE into an AI-assisted workshop with tools for ESPs, Papyrus, BSA archives, NIF files, and testing. In other words, the technology already exists and works. It's just that almost any game currently means almost any game whose internals you can expose to the agent in a usable way.

What You Need to Create Mods with Claude Code

The minimum setup is simpler than you might expect. In most cases, you don't need a separate computer for AI or a local model running on 128 GB of RAM. Claude Code works as a terminal agent and uses files on your own computer. Everything else depends on the game you choose.As a baseline, prepare:
  • Claude Code - the main agent that will read the project, edit files, run commands, and analyze errors;
  • a legitimate installed copy of the game - preferably without ten layers of old mods on top of it;
  • a backup of the game, or at least of the files you'll be changing;
  • Git - strongly recommended so every change can be rolled back;
  • game-specific modding tools - for example, BepInEx or MelonLoader for some Unity games, SKSE and Creation Kit for Skyrim, tModLoader for Terraria, REDkit for The Witcher 3, and so on;
  • a decompiler or analysis tools if the game doesn't provide a proper SDK;
  • fal.ai or another asset generator if you also want the agent to handle graphics, audio, or 3D assets.
Don't point Claude at your Elden Ring folder on the first evening and type add World of Warcraft to this. Even modern agents have a line between an ambitious project and pure madness. For a first test, pick something small: a new item, changed weapon stats, a simple mechanic, an extra button, or a minor visual mod.

How to Install Claude Code on Windows

Anthropic currently recommends the native installer. Open PowerShell and run:
  • irm https://claude.ai/install.ps1 | iex
You can verify the installation with:
  • claude --version
Then move to your project folder or prepared working directory and run:
  • claude
This opens the Claude Code terminal interface. The first launch will ask you to sign in to your account. You can find Anthropic's current official instructions in the Claude Code getting started guide.On macOS and Linux, the installation command is different:
  • curl -fsSL https://claude.ai/install.sh | bash
You can still install it through npm, but the native installer is simpler and depends less on the state of Node.js on your system. Especially if the last time you saw the word npm was inside an error message and you'd rather keep it that way.

Create a Separate Working Folder and Make a Backup

This is the step you'll be most tempted to skip, which is exactly why you shouldn't. Claude Code can change a lot of files very quickly. That's an advantage right up until the moment the agent confidently decides an old config is no longer necessary and ten minutes later you discover that half the mod depended on it.Create a separate project directory and, whenever possible, use Git. If the game has an official SDK or an established modding framework, keep the mod's source files separate from the game itself and copy only the finished build into the required directory. If a specific toolkit has to work directly inside the game folder, as some Skyrim setups do, make a full backup first.A well-organized project might look roughly like this:
  • my-mod/
  • ├── CLAUDE.md
  • ├── docs/
  • ├── src/
  • ├── assets/
  • ├── decompiled/
  • ├── build/
  • └── tests/
It's best to exclude the decompiled-code directory from a public Git repository from the start. Decompilation can help the agent understand the game's API and internal logic, but that doesn't mean you can redistribute the resulting code with your mod. Accessibility Mod Template, for example, already places decompiled/ in .gitignore and recommends keeping only method signatures, parameter names, enums, and short behavioral notes in the documentation.

How to Choose a Game for Your First AI Mod

The easiest option is a game with an established modding ecosystem. Claude doesn't have to invent a loader from scratch, guess resource formats, or poke at a binary with a toothpick. Unity games are often a convenient starting point because BepInEx, MelonLoader, Harmony, and solid C# decompilers are widely available.A rough difficulty scale looks like this:
  • easiest - games with an official SDK, mod workshop, or open API;
  • manageable - Unity and other games with long-established community mod formats;
  • harder - games without an SDK where you need to decompile C#, inspect assets, or manually find injection points;
  • very hard - closed native engines, C/C++, obfuscation, anti-cheat, or no meaningful modding scene;
  • I hate having free time - trying to move an entire game into another game built on a completely different engine.
If you're interested in installing existing mods rather than creating them, we already have a separate guide to installing mods in The Witcher 3 Remastered. Here, we're specifically talking about creating your own modifications with AI.

How to Give Claude Information About the Game

Claude Code is only as useful as its understanding of the project. If you open an empty folder and type make a Terraria mod, it can explain the general approach, but it won't see the real classes, methods, build system, or dependencies used by your version of the game. That's why the first stage is almost always research.For a game with an SDK, you can put the template source code and documentation into the project. For a Unity title, you can decompile managed assemblies and give the agent access to the relevant classes. More complicated games may require Ghidra, IDA, Binary Ninja, and MCP bridges that allow Claude to query functions, strings, references, and binary structure directly from a decompiler.The real prototype-decomp project, for example, uses a Ghidra MCP integration that lets Claude Code inspect and annotate the program opened in Ghidra while gradually replacing original functions with its own implementation. In Maurice Heumann's Modern Warfare 2 decompilation project, several Claude agents worked in parallel on different subsystems of the game. This is well beyond AI wrote a config for me. It's closer to software archaeology.For your first mod, a prompt to the agent should look something like this:
  • Study the project structure and the documentation in CLAUDE.md.
  • Do not modify the original game files directly.
  • First, identify which classes are responsible for weapons and item creation.
  • Create an implementation plan for a new weapon and list every file that will need to change.
  • Do not edit anything until the analysis is complete.
At least this way, you get to see where Claude intends to go before it starts changing things. And if the answer suggests rewriting the entire engine to add a sword with +5 damage, you can stop the revolution before it begins.

Why You Need CLAUDE.md

CLAUDE.md is one of the most useful files in the entire workflow. It acts as persistent project instructions that Claude Code reads while working with the repository. This is where you should describe the mod structure, build commands, game path, framework, restrictions, and safety rules.For example:

# Project rules

Game: Example Game
Mod loader: BepInEx
Language: C#
Build command: dotnet build
Output: ./build/

Never modify original game files.
Never commit files from ./decompiled/.
Before changing public hooks, check docs/game-api.md.
After every code change:
1. Build the project.
2. Read compiler errors.
3. Fix them.
4. Copy only the finished DLL to the test profile.
In larger modding toolkits, these instructions can be much more extensive. Skyrim-Claude Code Modder's Toolkit, for example, contains its own knowledge base covering Papyrus, ESP, NIF, BSA, and mod manager quirks. That's one reason a specialized toolkit generally works better than simply telling the agent, Claude, you're a Skyrim expert now. Good luck.

How to Install Plugins and Skills for Claude Code

The terminology can get confusing here. The Claude ecosystem currently uses plugins, skills, hooks, and MCP servers. For the user, the label matters less than the capability each one gives the agent.A plugin can install a collection of skills and tools at once. Skills usually contain specialized workflows and instructions. MCP gives Claude access to an external program or service, such as Unity, Skyrim, Ghidra, or fal.ai.If a developer distributes a tool through a marketplace, the process usually looks like this:
  • claude plugin marketplace add AUTHOR/REPOSITORY
Then:
  • claude plugin install PLUGIN-NAME
Some skills are installed simply by copying or cloning the repository into:
  • ~/.claude/skills/
After installation, check /skills or the documentation for the specific project. There is no single universal command for every third-party package. An author may distribute it as a plugin, skill, MCP integration, or ordinary project template.And always check what you're installing. Claude Code plugins can run local commands and MCP servers with your user permissions. A random GitHub repository called SUPER AI MODDING ULTRA 9000 is not the place to turn your brain off first.

How to Connect fal.ai for Sprites, 3D Models, and Audio

Claude Code itself can write code and control tools, but specialized models are generally more convenient for generating new textures, sprites, music, and 3D models. fal.ai works well for this.There is an open-source fal.ai skill for Claude Code. Once connected, the agent can search the fal.ai catalog for an appropriate model, show you options and pricing, run a cheap test generation, and only proceed to a full-quality run after approval.Installation through the marketplace:
  • claude plugin marketplace add morozovdd/fal-ai-skill
Then:
  • claude plugin install fal-ai
You'll also need a fal.ai account and API key. Generations are billed separately and are not covered by your Claude subscription.With this setup, you can ask the agent to:
  • create sprites and textures;
  • remove image backgrounds;
  • generate or modify a 3D model;
  • create sound effects;
  • generate music or voice;
  • upscale finished assets;
  • prepare multiple images in a consistent style.
This is where things get especially fun. Instead of going through the chain of draw image, download manually, open Blender, convert, put it into the project, update the code, Claude can move the asset through several tools and place the finished file exactly where the mod expects it. You should still inspect the first few iterations yourself. AI remains perfectly capable of generating a sword with three handles and confidently calling it an artistic choice.

What Creating Your First Mod Looks Like

Let's say we want to add a new weapon to a supported Unity game. Once the project is prepared, you could give Claude a request like this:Create a new one-handed weapon called Fire Axe.Requirements:
  • use the project's existing modding framework;
  • do not modify the original game files;
  • find the closest existing one-handed weapon type and use it as the base;
  • damage should be 15% higher than the base equivalent;
  • attack speed should be 10% lower;
  • add a fire effect on hit;
  • create a separate icon;
  • first create a plan and list all required files;
  • after implementation, build the project and fix compilation errors.
Claude will first inspect the available classes, find a suitable item template, and prepare the code and dependencies. If fal.ai is connected, your next request can ask it to create an icon or texture matching the original UI style. The agent can then run the build and read compiler errors.The most useful part isn't that Claude wrote a hundred lines of C#. Modern models could already do that. The important part is that the agent can work through the entire cycle itself: change the code, run dotnet build, notice that a method has a different name, find the real signature in the decompiled assembly, fix the call, and build the project again.

How to Make Claude Test the Mod

A successful compilation does not mean the mod actually works. Anyone who has ever developed software just smiled sadly.There are several approaches to automating tests. In games with an accessible API, you can write unit tests and integration checks. Skyrim has tools that allow Claude to interact with the running game through SKSE and MCP. SkyLink AI, for example, exposes dozens of commands for reading world state, inventory, quests, NPCs, and calling Papyrus functions while the game is running.Automation can go even further in web games. There are Claude Code skills based on Playwright that can launch a project, press keys, take screenshots, and record gameplay to MP4. The agent can then inspect the result and determine that the character is stuck in a wall, a button doesn't respond, or the new enemy has decided to fly into space.For a regular PC game without this kind of interface, the human remains the main QA engineer. Launch the mod, reproduce the problem, save the log, and send it back to Claude:
  • The mod loaded, but the game crashed when I selected Fire Axe.
  • Here is the log from BepInEx/LogOutput.log.
  • Find the cause. First explain the error, then fix the code and rebuild the project.
You can repeat this cycle until everything works. That's the real power of AI-assisted modding: not one prompt and suddenly Skyrim 2 exists, but extremely fast iteration between idea, code, build, test, and fix.

Can You Really Mod Almost Any Game?

Technically, Claude can help with almost any game whose files can be investigated. But the word help matters more here than any. If a project has documentation, an SDK, and an established modding community, the agent may be able to handle a large portion of the process almost independently. If you're dealing with a closed native engine with no symbols or documentation, you'll need serious reverse engineering before that becomes possible.The most problematic cases include:
  • games with anti-cheat;
  • online games where client modification is prohibited;
  • projects with encrypted or heavily obfuscated files;
  • console games without an accessible PC version and usable tools;
  • games where binary modification violates the user agreement or local law.
So viral videos are better understood as demonstrations of the upper limit of what is possible, not as repeat this in five minutes tutorials. Minecraft inside Elden Ring is impressive precisely because behind the neat video sits a huge amount of reverse engineering, automation, and intermediate code that Claude can process much faster than a person.

How Much Does It Cost?

Claude Code is available through paid Claude plans. Usage depends on the plan you choose and the scale of the project. A large decompilation project involving thousands of files can burn through limits very quickly.External services are billed separately. If you connect fal.ai and end every other prompt with now generate 40 more texture variations, that balance will start shrinking too. Authors of specialized skills note that a small complete graphics pass involving a few dozen sprites can stay in the single-digit dollar range, but the cost rises quickly once you start iterating heavily.That's why it's better to make the agent work with temporary placeholders first. Generate the final assets once the mechanic itself works. Creating twenty expensive 3D models for a system you'll throw away an hour later is an extremely authentic game development experience, but you don't have to recreate every part of the industry.

What Should You Ask Claude to Do First?

If you want to try the technology right now, don't begin by decompiling a huge AAA game. Pick a project with a known modding framework and give the agent one small, complete task.Good starting options include:
  • change the stats of an existing item;
  • add a new crafting recipe;
  • create a simple weapon based on an existing class;
  • add a new option to a menu;
  • change the behavior of a single NPC;
  • create a small visual effect;
  • add a hotkey for an existing function.
Once your first modification works, you can start adding asset generation, automated testing, and more complicated reverse engineering. This is a much faster way to learn where Claude genuinely saves hours and where it starts confidently building you a spaceport when all you asked for was a shed.

Is AI-Assisted Modding Worth Trying?

Yes, especially if the thing that previously stopped you from modding was the need to spend a month learning someone else's API, another week configuring the environment, and then finally receive a 700-line error message and quietly close Visual Studio.Claude Code doesn't remove the technical complexity of games, but it dramatically lowers the barrier to entry. The agent can inspect unfamiliar code, explain class structure in plain language, write an initial implementation, build it, read the errors, and repeat the cycle. Add MCP integrations for game engines and decompilers, plus fal.ai, and the result is no longer just a chat window that generates code. It's a fairly complete automated pipeline.Unfortunately, this approach won't work equally well for every game. The less understood a game is, the more work you'll need to do before getting your first useful result. So mods for almost any game is a fair description, as long as you add the fine print: assuming you have the tools, time, patience, and willingness to occasionally watch the AI fix the same mistake for the third time after creating it itself.

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