Anthropic bars Claude Opus 5.5 from recreating existing games
Claude Code staffer Addy Osmani confirmed two prompts were added to the model and said IP infringement violates Anthropic's usage policy.
Anthropic has added restrictions to Claude Opus 5.5 aimed at stopping the model from recreating existing games, according to automaton-media.com. The rule appears under the flag name "tengu_heron_brook" and cannot be disabled by users.
Addy Osmani, who works on Claude Code at Anthropic, confirmed in a reply that two prompts were added to Opus 5.5 to prevent game imitation. He said using Claude to infringe others' intellectual property violates the company's usage policy.
The rule still permits games built from original ideas, from other games within a genre, and from designs and assets the user owns. It forbids recreating specific existing games, even if the title is changed or the result is presented as original.
X user chasm publicized the rule on October 30, saying it had been added to Claude Code around October 27.
Clones and pressure on developers
Claude Opus 5.5 was released in September 2026 and posts better benchmark results than the earlier higher-tier model Claude Fable 5.1 at a lower token price. Clones believed to be AI-generated appeared in large numbers for Studio Bitdot's in-development title after a development video spread on social media before release.
Extortion cases have also been reported in which people demand money from developers in exchange for not releasing clone games. Valve, which operates Steam, has indicated it will not actively intervene against AI-generated clones.
Osmani said Anthropic will keep improving to strike an appropriate balance and asked rights holders whose own works are refused to contact the company directly.
Quick answers
What does the Claude Opus 5.5 rule forbid?
Recreating specific existing games, even with a changed title or when the result is claimed as original. Original ideas, genre-based works and the user's own designs and assets are still allowed.
Can users turn the restriction off?
No. The rule, distributed under the flag name "tengu_heron_brook", cannot be disabled by users.
When was Claude Opus 5.5 released?
Anthropic released it in September 2026.