We added two sentences to Claude Code’s prompt on Opus 5.5 to steer it away from recreating someone else’s specific game because using Claude to infringe IP is against our usage policy.
Original games, genre games, and games built from your own designs and assets are meant to keep working.
We’ll continue to iterate to ensure we’re striking the right balance. In the meantime, if Claude turns down something that’s yours, send it my way.
— Addy Osmani (@addyosmani) October 30, 2026
A massive wave
Anthropic’s new prompt comes as AI coding tools are powering a deluge of game projects based on existing work in one way or another. That includes thrown-together copies of game demos that are making some developers afraid to show their early work publicly, as well as thousands of AI-powered decompilation and porting projects for retro games. Thanks to AI tools, what used to be a time-consuming process requiring painstaking human effort is now orders of magnitude more efficient (though some veteran coders complain that these vibe-coded ports and decomp projects fail to clear the same quality bar as human-centered efforts).
The trend has gotten so bad that decomp.dev—a years-old community devoted to the “brutally difficult, time-consuming task” of game decompilation—announced it was shutting down last month. Community maintainer Luke Street wrote that quickly improving AI tools had made it clear that “community aspect of decompilation has been broken” as newcomers “rac[e] to port games, especially utilizing decompilations that they did not contribute to.”
“Decomp.dev was originally designed to gamify decompilation: watching the progress go up was a fun way to stay motivated when every fraction of a percent took real human effort,” Street wrote. “Today, that same idea has warped decompilation into a hollow numbers game, exacerbated by folks who just want to burn tokens to make number go up or ‘port game to PC,’ all else be damned.
Like trying to stop the tides
While Anthropic’s new prompt can be seen as a noble effort to push back against the flood of AI-powered, vibe-coded copying, it seems unlikely to have much impact overall. That’s primarily because eager game copiers can simply shift to any of the other frontier models that haven’t introduced such restrictions. And even if the AI industry as a whole began to bar this kind of use case, coders could switch to cheaper open-weight models that aren’t subject to these kinds of restrictions and are not all that far behind in capabilities.