Anthropic Quietly Told Claude Code to Stop Cloning Games and Developers Say It Hit Their Own Work

Two sentences. That is all Anthropic says it added to Claude Code's prompt to stop people cloning video games with its coding agent. The company did not announce it. Users found it through refusals, and some developers say it is catching work that has nothing to do with piracy.

The trail starts with an X user called Chasm, who posted a screenshot of what looked like a new instruction. As reported by Tom's Hardware, the text reads: "Do build original games, games in a genre, and games from the user's own designs and assets. Don't build a recreation of a specific existing game, even if it is renamed or called original." The Verge printed the last word of that sentence as "named" rather than "renamed", so treat the screenshot wording as unconfirmed.

Anthropic has not confirmed those exact words. It has confirmed the substance. On October 30, Anthropic's Addy Osmani replied on X.

"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." Addy Osmani, Anthropic, on X, October 30

He added that Anthropic will "continue to iterate to ensure we're striking the right balance," and invited users to send him any case where Claude turns down something that is theirs.

The collateral damage is the story

The policy logic is easy to follow. Anthropic's usage policy lists infringing the intellectual property rights of a third party under things users must not do with Claude. Retro gaming is currently being overrun with AI-made decompilations, recompilations and ports, according to The Verge, so the timing is hardly random.

The execution is the problem. A prompt line is a blunt instrument, and the people reporting trouble are not the ones Anthropic says it is targeting. In a GitHub issue filed in the Claude Code repository, a developer who says they run Conflict Simulations LLC describes building digital board wargame modules on paid commission, from materials supplied by clients who own the physical games. Sessions that did that work for months, the developer writes, now refuse to continue. The developer also says the refusals started only after they asked Claude whether the new rule applied to their work. The developer dates the arrival of the server-side instruction to around October 27. That date comes from the user, not from Anthropic.

XDA Developers says it found the exact instruction inside version 2.1.314 of the Claude Code binary, delivered through a remote configuration field, and found a separate Opus 5.5 mechanism for the same guidance. In XDA's own tests, Opus 5.5 still agreed to help with a Pokémon Diamond decompilation and a static recompilation, which suggests the rule is narrower than the loudest complaints imply. XDA says it has not reproduced the wargame refusals.

Then there is the reverse engineering claim. Tom's Hardware says users on GitHub are complaining that Claude Code refuses reverse engineering tasks. Its former writer Jarred Walton told the outlet that checks on software he is developing ran fine until October 31, and that switching to Opus 4.8 let him carry on. He theorises that Anthropic may have added a separate rule for reverse engineering. That is a theory. Nothing Anthropic has said mentions it, and the confirmed change covers games only.

Tom's Hardware also says the game blocking appears limited to Claude Code paired with Opus 5.5, so a different harness might sidestep it.

The deeper issue is how this shipped. A behavior change that can cancel paid client work arrived through a remote prompt, with no announcement, and surfaced through a screenshot. Anthropic deserves credit for answering within days. But "send it my way" is one employee's inbox, not a policy. If Claude Code is going to judge who owns a game's designs, developers will want to know how, and who decides.