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Claude Code has been updated to stop cloning existing video games, even if they use a new name.
Claude Code will now only build original games, games within a genre, and games based on a user’s own designs and assets. It will not build a clone of a specific existing game, even if the project is renamed or called original. And there is no way to turn off this restriction.
ANTHROPIC IS CRACKING DOWN ON VIDEO GAME REWRITES 🚨
Claude Code picked up a new rule around Oct 27, sent from Anthropic’s servers under a flag called "tengu_heron_brook". There’s no setting to turn it off.
The full rule: “Do build original games, games in a genre, and games… pic.twitter.com/0Zc5mQWHJt
— chasm (@chasmmmmmmmmmmm) October 30, 2026
Anthropic confirmed the change through Addy Osmani, a member of its technical staff, and a company spokesperson pointed Game Developer to his statement. Osmani wrote that two sentences were added 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 intellectual property is against the usage policy. He added that original games, genre games, and games built from a user’s own designs and assets are meant to keep working. He also said Anthropic will keep iterating and asked developers whose own work is declined to send him reports.
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…
— Addy Osmani (@addyosmani) October 30, 2026
The move follows concern across the games industry about AI-assisted copying. The most recent Steam Next Fest had twice as many demos as the previous one, and AI-assisted games made up most of the increase. Digital Sun Games, the developer of the Moonlighter series, delayed a public playtest of its next game, ReVamp, over fears that a clone could reach the market first. Valve has said it does not want to decide which tools developers use, and it suggested that developers make their games harder to copy.
Developers have raised several concerns since the rule became public:
- A developer who runs Conflict Simulations LLC filed a GitHub issue on October 30. The developer says Claude Code began refusing to build custom digital board-wargame modules for customers who own the physical games. The developer says the code is original, but the game publishers do not license the work, and that the refusals began only after asking Claude whether the rule applied.
- Some self-described game developers say Claude refused anti-cheat work and security reviews on their own games.
- Tom’s Hardware reported additional user complaints that Claude is refusing reverse-engineering tasks, although no direct link to the game rule has been established.
That last point matters because the timeline does not fit neatly. A Reddit thread about Claude cutting off reverse-engineering work appeared on October 21, and Kotaku covered similar complaints on October 24, which is three days before the game rule was reportedly pushed. Anthropic’s Opus 5.5 announcement also describes separate cybersecurity safeguards, and reporting has not tied those safeguards to the game rule. XDA reportedly asked Opus 5.5 about a Pokémon Diamond decompilation project, and the model agreed to help while distinguishing reverse engineering from recreating a game. That was one request, so it does not show how every case is handled.
The rule also has limits. Claude cannot verify whether a user owns a game, and locally run models do not carry the same restriction. Game Developer noted that the rule may deter only the most low-effort copycats. Anthropic has not said how it defines a recreation, and no published exemption process for game developers has been reported. The rule text does not explicitly prohibit modding or optimizing existing games, so how it applies to ports, mods, and decompilation projects remains unclear.
How Anthropic handles borderline cases, such as ownership-based custom work, ports, and mods, will show how narrow the rule is in practice.
