Anthropic has added new instructions to Claude designed to stop its models from recreating specific existing video games. The company introduced the change in Claude Code as concerns grow over the use of AI for game copying and porting.
The change was first noted late last week by a social media user known as “chasm,” who identified a new rule in a JSON file named “tengu_heron_brook.” The instruction tells Claude to create original games, games within a genre, and projects based on a user’s own designs and assets, while prohibiting recreations of specific existing games, even when they are renamed or presented as original works.
XDA later reported that the rule appears in version 2.1.314 of the Claude Code binary, released on October 30. The publication also found that the same identifier had served other purposes in earlier versions and that Claude Opus 5.5 appeared to have separate instructions restricting game recreations.
Anthropic software engineer Addy Osmani confirmed that the company had added two sentences to Claude Code’s prompt for Opus 5.5. He said the goal was to steer the model away from recreating someone else’s specific game because using Claude to infringe intellectual property violates Anthropic’s usage policy.
Osmani said the revised prompt is still intended to permit original games, genre-based projects, and games built from users’ own designs and assets. However, several reports on Anthropic’s GitHub indicate that the restriction has interfered with some game-development use cases.
The new safeguards may reduce Anthropic’s exposure to liability, but they are unlikely to halt the wider expansion of AI-assisted game copying. The broader wave involves more than a single model provider, limiting the effect that Anthropic’s rules can have on the overall trend.
Sources: Ars Technica.