Claude Code quietly started refusing to rebuild existing games
A server-side instruction, with no setting to turn it off, now tells Claude Code not to recreate an existing game even under a different name, and it is catching licensed commercial work in the process.
Anthropic shipped a new server-side instruction to Claude Code around 27 October that tells the model: “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.” It arrived with no changelog entry and no setting to disable it. Developers found it by running into refusals mid-session.
The instruction is delivered under an internal flag, reportedly named tengu_heron_brook, with no exemption path for legitimate cases. A GitHub issue filed on 30 October describes a professional studio, building digital modules of board wargames under a paid commission and using only original code and assets supplied by the rights holder, getting blocked anyway. Anthropic’s support bot told the developer the policy “applies to all customers without exception”, and escalation to a human gave no timeline.
Why it matters: a category-level block like this cannot distinguish piracy from licensed, original work that happens to resemble something that already exists. If your Claude Code workflow touches game logic, even for a commissioned port or an educational remake, expect refusals with no visible toggle to appeal to.
The caveat: this is unconfirmed by any official Anthropic announcement. Everything here comes from the GitHub issue, support replies quoted in it, and independent reporting; Anthropic has not published a statement explaining the rule’s scope or an exemption process.