Claude’s new rules against game cloning won’t stop the AI copying boom

Anthropic unveiled a fresh system prompt late last week that intends to deter its Claude models from replicating certain pre-existing video games. Although this step could mitigate potential legal risks for Anthropic, it is improbable to curb the vast surge of AI-supported game adaptation and duplication that has been surging in recent times.

Social media user and AI decompilation aficionado known as chasm was among the first to spot the prompt alteration late last week, announcing a new regulation appearing in the Claude Code prompt around October 27. This regulation, located in a JSON file under the name tengu_heron_brook, stipulates that original games, games in a genre, and games from the user's own designs and assets should be created.

However, recreations of specific existing games, even if renamed or called original, are prohibited. XDA subsequently independently confirmed that the new rule is incorporated in version 2.1.314 of the Claude Code binary, released on October 30. XDA also reported that the tengu_heron_brook rule had been employed for different reasons in earlier versions and the Claude Opus 5.5 model specifically possessed its own unique and separate instructions limiting game recreations as part of its system prompt bundle.