Anthropic updates Claude Code to block AI video game clones

Anthropic modified the system prompt for Claude Code on November 2 to restrict the AI tool from replicating established video games. The change targets direct clones of specific titles while permitting users to build original games or titles based on their own designs. This adjustment follows a surge in retro gaming projects where developers used the AI to decompile, recompile, and port existing software.

The update emerged after a user on X shared a screenshot of the new instructions. The text directs the model to build games from the user's own assets and to avoid creating a recreation of a specific existing game, even if the user calls the project original. The company confirmed the changes apply specifically to the Opus 5.5 model.

Addy Osmani, a member of Anthropic's team, addressed the update in a public reply. He stated that the two new sentences were added to steer the tool away from infringing on intellectual property. Osmani noted that using Claude to recreate someone else's specific game violates the company's usage policy. He added that original games and those built from a user's own designs should continue to function as intended.

Osmani said the team will continue to refine the prompt to find the right balance between utility and protection. He invited users to contact him directly if the new rules cause Claude to reject a project that belongs to them. The company has not yet stated whether similar updates will apply to other Claude system prompts.

The move aims to clarify the boundaries for developers using AI coding tools. It distinguishes between creating a game in a specific genre and building a pixel-perfect copy of a known title. This distinction matters for the growing number of retro gaming projects that rely on AI assistance.