--- title: Hobbyists Are Rebuilding Call of Duty With Off-the-Shelf AI While Most People Still Learn What an Agent Is description: A Modern Warfare 2 engine written by AI now runs Skate 3 and Minecraft, and free repos let anyone mod games or replace paid software with a pasted prompt. author: Darie Nani (Editor-in-Chief) date: 2026-10-05T13:27:07.162Z updated: 2026-10-05T13:27:07.172Z canonical: https://www.sovereignmagazine.com/article/ai-mods-call-of-duty-off-the-shelf-ai image: https://cdn.nanimediahouse.com/mw2-skate-3-mashup-ai-mod.webp categories: Artificial Intelligence, Startups content_type: News publication: Sovereign Magazine --- In the middle of September, a developer known online as vladtrc published IW4L, a new engine for Call of Duty: Modern Warfare 2 written from scratch in the Rust programming language, and two weeks later a modder called chasm had used it to put Skate 3's skateboarding and a working Minecraft world into the 2009 shooter. "This whole project is written by an LLM," vladtrc writes in the [project's documentation](https://github.com/vladtrc/iw4L). Projects like this use AI coding agents such as Anthropic's Claude Code, which comes with the $20-a-month Claude Pro plan, and [OpenAI's Codex](https://www.sovereignmagazine.com/article/openai-codex-plugins-ai-coding-tools), which comes with ChatGPT. Mainstream media is still asking basic questions about AI, such as what it is and how it works. Meanwhile, hobbyists are already using AI tools to take apart and rebuild entire game engines ## A Call of Duty Engine Written by an AI Model IW4L does not patch the original game. It reads the maps, models, textures and weapons from a copy of Modern Warfare 2 that the player already owns and runs them in its own engine. It translates the game's original Direct3D 9 shaders into a modern format, and vladtrc used Ghidra, the free reverse-engineering tool released by the US National Security Agency, to inspect the original program files. Players can explore the multiplayer maps, fight bots and play online against each other. Chasm's version, published on 27 September, adds a Skate 3 mode. Pressing J drops the soldier onto a skateboard that uses Skate 3's own physics, tricks and grinds, which the game takes from the player's own Xbox 360 copy of Skate 3. A separate Minecraft map uses an open-source Rust version of Minecraft to generate an endless world, with blocks that break under fire according to each gun's damage. Neither project includes any game files, so players supply their own. Oblivion Remastered took Virtuos and Bethesda about four years before it came out in April 2025. A commercial remaster rebuilds every model and texture to a finished standard, and IW4L's documentation warns that "gameplay remains incomplete". Even so, two hobbyists went from IW4L appearing on GitHub to a playable mashup of three games in two weeks. ## AI Agents Are Speeding Up Reverse Engineering That Took Volunteers Years Reverse engineering a game has traditionally taken volunteer teams years. > "Decompilation, instead of being a passion project with tons of human hours over years can instead become a couple of highly specialized people glueing together tons of token output." > — Stephen Jayakar Stephen Jayakar wrote that on his blog this year, after using AI agents on the volunteer project to decompile Super Smash Bros. Melee, which turns the 2001 GameCube game back into readable source code. Volunteers began the project in 2020. Jayakar set up one agent to plan the work, others to write the code and another to judge the results, all running on Anthropic's Claude. Before that, he said, it took him a day to decompile a single function. By the time he wrote the post, he had merged about 20 functions and had 80 more under review. The Melee project reached 100% in September, and at least one contributor publicly credited Claude for help in the final stretch. Reading and understanding another studio's code is the work that used to stop most hobbyists before they started, and it is the work the agents have sped up most. A modder with an agent can now get a playable version of an idea within days. ## You No Longer Need to Be a Modder to Build Your Own Mods The modders are also handing that ability to people who have never modded a game. IW4L builds on years of community work and credits earlier projects such as IW4x and OpenAssetTools, which had already worked out how Modern Warfare 2 stores its files and talks to its servers. A player needs none of that knowledge. IW4L and chasm's mashup both come as Windows downloads, and the player double-clicks the program and confirms where Modern Warfare 2 is installed. [Universal-modder](https://github.com/rehan-remade/universal-modder), published on 30 September by a developer called rehan-remade, applies the same idea to almost any PC game. It is a set of instructions and tools that the main AI coding agents can follow, including Claude Code, Codex, Google's Gemini CLI, Cursor, GitHub Copilot and OpenCode, and it had more than 3,500 stars on GitHub within five days. The player types a request in plain English. The project's own example asks the agent to "add a homing missile launcher and a tactical nuke that craters the world" in Terraria. From there, according to the documentation, the agent "finds the game, works out the engine and the route, reads the real code, builds the mod, makes art, 3D and sound with fal, tests it in the running game, cuts the video, and writes down what it learned for the next agent." Those notes, in effect recipes for modding each game, go into a shared knowledge base that the next person's agent reads before it starts. ![First-person view in Grand Theft Auto V holding Minecraft's diamond sword and ender pearl, with a police car in the street ahead](https://cdn.nanimediahouse.com/minecraft-gta-v-universal-modder.webp) *Minecraft running inside Grand Theft Auto V, from a demo of a mod made with universal-modder. — Photo: Screenshot: @rehan_shei / universal-modder* The knowledge base held 39 notes within a week. In two of them, Minecraft runs inside Grand Theft Auto V and inside Portal 2, with both games open at the same time and passing information to each other. Another moves Halo 3's weapons, vehicles and maps into Minecraft from the player's own copy of the Halo collection, and another converts Elden Ring's offline game to play like Counter-Strike 2. Most of the notes name Claude Code as the agent that did the work. Each of those steps used to need a specialist who could read a game's code and knew the tools for changing it. The person asking for the mod now needs to know none of it. ## AI Agents Now Install and Maintain Free Alternatives to Paid Software Ordinary software is going the same way. Open-source alternatives now exist for most kinds of paid software, and some are very large. [Twenty](https://github.com/twentyhq/twenty), which calls itself "the open alternative to Salesforce, designed for AI", has almost 58,000 stars on GitHub. [Plane](https://github.com/makeplane/plane) offers an open-source alternative to Jira, Linear, Monday and ClickUp, [Documenso](https://github.com/documenso/documenso) to DocuSign, and [Coolify](https://github.com/coollabsio/coolify) to the hosting services Vercel, Heroku and Netlify. [Immich](https://github.com/immich-app/immich), a self-hosted photo and video library, has more than 115,000 stars. Most people never used them because setting them up and keeping them running needed someone comfortable with servers and the command line. Projects now hand that job to the user's AI agent. [OpenWork](https://github.com/different-ai/openwork), an open-source alternative to Anthropic's Claude Cowork that has gathered almost 24,000 stars since January, tells visitors to "copy this prompt and paste it into Claude Code, Cursor, Codex, ChatGPT, or any agent that can run commands on your computer." The prompt reads: "Install OpenWork on my computer, set up my first workspace, and open it ready to use." By December 2025, more than 60,000 open-source projects had added an AGENTS.md file, a set of instructions written for AI agents instead of people, according to the Linux Foundation. Keeping self-hosted software updated and secure was the other thing that kept most people away from it, and that is also changing, because the owner no longer needs to understand code or servers to do it. They only need to know the work has to be done, and can ask an agent to update the repo or find security holes and fix them. Investors are already pricing in the risk to paid software. On 3 February, software stocks lost about $285 billion of value in a day after [Anthropic released plugins that let Claude Cowork do legal, finance and sales work](https://www.sovereignmagazine.com/article/cowork-is-a-big-disappointment-285-billion-wiped-because-of-this). Adobe's revenue is still rising, but its shares fell below $275 in June for the first time since 2019 as investors weighed whether AI will make its Creative Cloud products easier to replace. ## AI Labs Use Their Own Models to Make the Next Ones The modders and the open-source developers all rely on models made by a handful of AI labs, which are further ahead again. Anthropic said in a June paper that "as of May 2026, more than 80% of the code we merge into Anthropic's codebase was authored by Claude," up from low single digits before [Claude Code](https://www.sovereignmagazine.com/article/anthropic-claude-code-source-code-leak) launched in February 2025. In a March poll of 130 of its research staff, the median respondent estimated that they produced about four times as much work with Claude Mythos Preview as they would have without AI. Anthropic released that model in April, and only to a limited group of partners. In one Anthropic experiment, two human researchers working for about a week closed roughly 23% of the gap on an AI safety problem. A group of Claude agents, given the same problem, closed 97% over 800 hours of combined work, using about $18,000 of computing power. Humans still chose the problem and how to score it. OpenAI said on 6 September that it had reached a goal, set in October 2025, of an automated AI research intern by September 2026. It describes this as a system that can carry out well-defined research tasks under human direction, including work that would take a skilled researcher several days. Its next target is an automated AI researcher by March 2028, and it says its work now includes progress towards AI that helps develop more capable AI. ## Where AI Mods and Software Could Be in Six Months At the pace of the past month, six months could bring agent-written recipes for most popular PC games, fan ports of older console games made in weeks, and install prompts on most open-source alternatives to paid software. Universal-modder's developer is already working on a mod hub where people can publish their mods and remix other people's. The people who publish these repos do the specialist work once, and anyone with a $20 subscription who can describe what they want can then use it. Game publishers, Adobe and [the SaaS companies](https://www.sovereignmagazine.com/article/vibe-coding-killing-saas-tools) have relied on that knowledge being scarce, and every repo an agent can install makes it less so. For someone who has only used a chatbot, the step up to modding a game or replacing a paid product is now a subscription and a pasted prompt. The labs, meanwhile, are using models the public cannot yet buy to develop the next ones, and are moving further ahead of everyone else. ## FAQ **Q: Is ChatGPT an AI agent?** ChatGPT started as a chatbot, which answers a question and stops. An agent is given a task and works through it on its own, reading files, running code, checking the result and trying again. ChatGPT's paid plans now include OpenAI's Codex coding agent, so the same subscription can be used either way. The modders in this article use Codex, Claude Code and similar tools in the second way. **Q: Is there a free AI coding agent?** Yes. OpenCode, one of the agents universal-modder supports, is open source and free to download, with more than 200,000 stars on GitHub, although it still needs an AI model to run on and most good models charge for use. One of the notes added to universal-modder's knowledge base on 5 October, a Valheim mod that turns a frost weapon into a returning thunder hammer, was made with OpenCode running a model from the Chinese lab DeepSeek, with no human listed as working on it. **Q: Is it illegal to decompile software?** It depends on the country and the licence. EU law allows decompiling a program in limited cases, mainly to make other software work with it, and US courts have accepted reverse engineering for that purpose as fair use. Many licences, including Adobe's terms of use, forbid it outright. The game projects in this article ask players to supply their own copies and do not distribute game files or decompiled code, but publishers can still take legal action, as Nintendo did against Switch emulators in February.