In context: Vibe coding and AI agents have made game decompilation and recompilation child's play, but things might soon change significantly. Claude Code is now being instructed to avoid performing this type of workload, meaning decompilation enthusiasts will need to turn elsewhere to get the job done.
Claude might soon stop being one of the best AI tools for decompiling and recompiling existing games. According to Anthropic programmer Addy Osmani, the model behind the company's vibe-coding service will now avoid user prompts that request recreations of someone else's video games.
The change was first spotted by decompilation enthusiasts over the weekend. On October 27, Claude Code started picking up a new rule hidden behind the "tengu_heron_brook" flag. The rule is designed to force the AI model to build original games based on users' own designs and assets, rather than content taken from games already on the market.
Read our feature: Decompilation on Steroids: Why AI Is Suddenly Cracking Open Old Software
Soon after the rule was discovered, Osmani confirmed that Anthropic was adding two new sentences to Claude Code's Opus 5.5 model. Recreating someone else's intellectual property is apparently against Claude's usage policy, meaning users should only be able to vibe-code "original" games. Osmani also said the company would continue iterating on the new rules to achieve the "right balance."
– Addy Osmani (@addyosmani) October 30, 2026
AI-assisted recompilation and decompilation projects have taken the IT world by storm. Vibe coders are now leveraging previous human-made research efforts to "port" console-exclusive games to PC – or vice versa. Projects such as AnyPS5 are even attempting to turn PlayStation 5 games into "native" PC titles.
The vibe-coded decompilation deluge is also having a significant impact on human-led research efforts. The decomp.dev website has now shut down because AI-assisted coding has undermined meaningful efforts to understand and document how game code works. Vibe coders are now forking existing decompilation projects and letting AI finish the job, or racing to port games to different platforms just to plant their flag on the map.
Vibe-coded game recreations might now be more difficult with Claude, but the decompilation "fun" is likely to continue regardless. Users will simply need to switch to other AI models and services, adapt to rapidly improving open-weight models, or resort to offline setups to keep churning out new recompilations and web-based conversions.