Anthropic steers Claude Code away from cloning existing games

Anthropic has confirmed it changed how Claude Code handles requests to rebuild existing video games. The change is a short instruction added to the tool’s prompt on Opus 5.5, and it tells the model not to recreate a specific existing game, even one that is renamed or called original.¹

An Anthropic staffer, Addy Osmani, described it as two added sentences meant to steer the model away from copying someone else’s game, because using Claude to infringe IP is against the company’s usage policy.¹ The rule reads: build original games, games in a genre, and games from the user’s own designs and assets, but not a recreation of a specific existing game.¹ The company says original and genre games are meant to keep working, and that it will keep adjusting the balance.¹

The rule surfaced through a configuration field called “tengu_heron_brook”, which showed up in Claude Code around October 27 and, per the user who spotted it, has no off switch.¹ XDA separately found the same text in version 2.1.314 of the Claude Code binary, plus a second mechanism that delivers the instruction specifically to Opus 5.5.² In XDA’s testing, Opus 5.5 refused to recreate Pokémon Diamond and cited its session instructions, while the older Opus 5 first refused, then said it would help with legitimate decompilation work.²

The timing is not subtle. Indie developers have spent weeks worrying that AI tools can turn a public demo into a clone that ships first. Digital Sun Games pushed its public ReVamp playtest to a Discord-only run, with a public one hoped for in January.³ Alliance Arts pulled the public demo of Drunken Goddess Reflux for the same reason.⁴ Seen it before: a new capability arrives, and the guardrail arrives after the incident reports.

The limits are worth stating plainly. Safety rules on generative AI tools have been repeatedly sidestepped with rhetorical tricks, and it is unclear how the software could tell whether a user owns a game idea or its assets.¹ The wording also leaves gray areas. It does not explicitly ban decompilation or static recompilation, the techniques behind projects like the Wind Waker HD PC port, though XDA notes Claude might not distinguish those from recreating a copyrighted game.²

There are reports that the pushback is wider than games. Users on Reddit say Claude has refused tasks involving unlicensed translations and have complained about new safety classifiers touching security research and coding books.⁵ Those are user reports, not confirmed behavior.

It is also unclear how widely the instruction is deployed or whether it becomes permanent across Anthropic’s models.²

Our read: This is a speed bump, not a wall. It will stop the laziest “rebuild this game” prompts, and it signals that Anthropic would rather not be the engine of the clone flood. But an instruction in a prompt is only as strong as the model’s judgment, and developers who fear fast-follow clones still have no guarantee. Watch for whether Anthropic spells out the rule’s edges, especially for recompilation and porting work, since that is where legitimate projects could get caught.

What you should do: If you build original games or genre games with Claude Code, nothing should change. If Claude refuses something that is genuinely yours, Osmani asked users to send it to him.¹

Footnotes

1. Game Developer, “Anthropic orders AI tool Claude to stop remaking video games”. Retrieved October 30, 2026. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

2. XDA Developers, “Anthropic seems to be testing a potential crackdown on vibe-coded ports of existing games”. Retrieved October 30, 2026. ↩ ↩² ↩³ ↩⁴

3. Rock Paper Shotgun, ““Too big a risk”: Moonlighter devs delay new game’s demo for fear of genAI cloning, calling on platforms to “keep strengthening protections for original work”“. Retrieved October 30, 2026. ↩

4. Ars Technica, “AI game clones are making indie developers afraid to show their work”. Retrieved October 30, 2026. ↩

5. Kotaku, “Anthropic Nerfs Claude Again To Stop Users From Making AI Slop Out Of Any ‘Specific Existing Game’”. Retrieved October 30, 2026. ↩