Anthropic adds two sentences to Claude Code's Opus 5.5 prompt to steer it away from recreating specific existing games; original and genre games still allowed
Around Oct 27, users noticed Claude Code receiving a new server-side rule (flag name tengu_heron_brook): build original games, games in a genre, and games from the user's own designs and assets, but do not build a recreation of a specific existing game, even if it is renamed or called original. The post that surfaced it drew about 8,700 likes and nearly 2 million views on Oct 30. The same day, Addy Osmani, who works on Claude Code at Anthropic, confirmed on X that the team added two sentences to Claude Code's prompt on Opus 5.5 because using Claude to infringe IP is against Anthropic's usage policy. He said original games, genre games, and games built from your own designs and assets should keep working, that the team will keep iterating, and that users can send him wrongly refused requests.
Key Takeaways
- Scope: the change is just 2 sentences in Claude Code's system prompt for Opus 5.5, pushed from the server with no user-side toggle (Addy Osmani's post)
- Rule text (per the flag tengu_heron_brook users captured): original games, genre games, and games from the user's own designs and assets are allowed; a recreation of a specific existing game is not, "even if it is renamed or called original" (original report, about 8,700 likes and nearly 2M views)
- Basis: Anthropic's Usage Policy prohibits using its products to infringe, misappropriate, or violate a third party's intellectual property rights
- Feedback path: Osmani says the team will keep tuning the line and asked users to send him wrongly refused requests; there is no separate Anthropic blog post yet, and benchmarks do not apply



