Anthropic cracks down on game cloning in Claude Code after wave of AI-built knockoffs

Anthropic is blocking Claude Code from recreating existing video games, with employee Addy Osmani confirming on X that two sentences in the system prompt for Opus 5.5 now prevent cloning of others' games, citing usage policy against intellectual property infringement. The rule has been active for several days and applies even when a clone is renamed or presented as original, while users can still build their own games, genre titles, and projects with custom assets. The change follows a wave of AI-powered cloning projects, including unofficial browser ports of titles like Halo and GTA Vice City made with Opus 5.5 and GPT-6 Astra.