Anthropic has steered Claude Code on Opus 5.5 away from recreating other developers' specific games. Addy Osmani, a member of Anthropic's technical staff, confirmed the change on X on October 30, 2026 (16:58:48 UTC), after developers spotted a new server-side rule days earlier. The company frames the step as enforcement of its usage policy against IP infringement, not a ban on original or genre games.

Key Facts

Details
What changed Two sentences added to Claude Code's prompt on Opus 5.5 to steer it away from recreating someone else's specific game
Official reason Using Claude to infringe IP is against Anthropic's usage policy (Osmani)
Still allowed (per Osmani) Original games, genre games, and games built from the user's own designs and assets
Developer-reported rule flag tengu_heron_brook (reported around October 27, 2026; no user toggle)
Rule text (developer reports) "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."
Anthropic confirmation path Spokesperson referred Game Developer to Osmani's X statement; Game Developer updated its story on October 30

Background

On about October 30, 2026, developer and YouTuber chasm (@chasmmmmmmmmmmm) posted that Claude Code had picked up a new rule around October 27 under the flag tengu_heron_brook, with no setting to turn it off. Multiple outlets quoted the same rule text. Game Developer, PC Gamer, XDA, Dexerto, and IT之家 all reported the discovery and Osmani's reply.

XDA independently found the same instruction inside Claude Code v2.1.314, and noted related identifiers original_games_guidance and opus_5_5_prompt_bundle. In XDA's tests, Opus 5.5 stated that session instructions barred recreating a specific existing game (including renamed versions). XDA also reported that Opus 5.5 still distinguished reverse engineering and static recompilation from building a recreation from scratch in some prompts, though that does not prove every session behaves the same way.

Fear of fast AI remakes has spread among independent developers in recent weeks. Game Developer reported that Digital Sun Games was among studios that canceled a planned public playtest for the upcoming game ReVamp, citing concern that a demo could be ingested into an AI tool. PC Gamer wrote that Steam has seen a large influx of low-effort AI-assisted games, that AI-assisted demos drove much of the increase at a recent Steam Next Fest, and that Valve's Tom Giardino said at Steam Indie Connect that Valve does not want to ban AI coding tools outright and prefers making the platform "smarter," while advising developers to keep adding features and personality that are hard to copy.

Reactions and Impact

Osmani wrote that Anthropic will "continue to iterate to ensure we're striking the right balance," and invited users to contact him if Claude turns down something that is theirs. Game Developer noted that safety limits on generative AI tools can often be worked around, and that users pointed out cloners could move to open-weight models without the same restriction. XDA reported a GitHub issue in which a developer said Opus 5.5 began refusing help on personalized digital modules for physical board wargames owned by customers; XDA said it had not independently reproduced those refusals.

What We Don't Know Yet

  • Whether the rule has been rolled out beyond Opus 5.5 to other models or Anthropic products.
  • How wide the deployment is (all accounts and sessions, or only some).
  • How Claude decides that a request is a recreation of a specific existing game versus a genre game or an original design, and where false refusals land.
  • Whether the current wording is permanent, or only an interim prompt that Anthropic will keep changing (Osmani said the company will continue to iterate).

Sources