Anthropic blocks game clones in Claude Code system prompt

Anthropic has modified Claude Code's system prompt to prevent users from recreating existing video games, though original game development remains supported. The change, implemented on Opus 5.5, adds language steering the AI away from building clones of specific titles while still allowing creation of original games, genre-based games, and projects built from user designs.

Key points

• Claude Code's system prompt now includes two sentences discouraging recreation of specific existing games
• The update applies to Claude Code on Opus 5.5 and aims to prevent IP infringement per Anthropic's usage policy
• Users can still build original games, games in a genre, and games from their own designs and assets
• Anthropic's Addy Osmani confirmed the company will continue iterating to strike the right balance
• The change comes amid a wave of AI-generated retro game decompilations and ports

How to use it

• Continue using Claude Code to build original game projects and prototypes without restriction
• Focus on genre-based games or implementations of your own designs rather than clones of existing titles
• If Claude Code incorrectly blocks a project you own or have rights to, report it to Anthropic for review
• Expect the policy to evolve as Anthropic refines the balance between creative use and IP protection

Has anyone run into this new prompt behavior when building games with Claude Code?