Anthropic has added restrictions to Claude Code on Opus 5.5 to prevent users from rebuilding specific existing games, following concerns from independent developers about AI-assisted clones.
Anthropic has changed Claude Code so its Opus 5.5 model will not recreate a specific existing video game, adding a restriction that addresses concerns from independent developers about AI-assisted clones.
The rule was added to Claude Code’s prompt on Oct. 27. It directs the tool toward original games, genre-based projects and games made from a user’s own designs and assets. It also covers attempts to disguise a recreation by changing its name.
“Do not build a recreation of a specific existing game, even if it is renamed or called original.” — Anthropic’s Claude Code rule
Anthropic did not issue a separate announcement about the change. A spokesperson directed Game Developer to a post by Addy Osmani, an Anthropic member of technical staff. Osmani said Anthropic had added two sentences to the Opus 5.5 prompt to steer Claude Code away from recreating another person’s specific game because using Claude to infringe intellectual property violates the company’s usage policy. He also said Anthropic would continue adjusting the system to balance those restrictions with legitimate development work.
Why the change matters to indie studios
The update follows several decisions by independent developers to limit public testing of unreleased games. Digital Sun Games canceled the public playtest for its upcoming game ReVamp after concerns that someone could submit the demo to an AI tool and release a copy before the original game. Drunken Goddess Reflux took a similar approach, moving its testing to smaller private sessions.
Those concerns extend beyond code-generation tools. Developers have also asked Valve how Steam will address games that imitate existing releases and compete with them on the storefront. At the Steam Indie Connect event in Busan, South Korea, on Oct. 27, Valve’s Tom Giardino and Marc Wilkinson acknowledged the issue.
Claude Code’s revised instructions distinguish between making a game within a familiar genre and reproducing a particular game. The allowed uses described in the prompt include:
- Creating an original game
- Building a game in an established genre
- Developing a project from the user’s own designs and assets
The restriction applies specifically to recreating an existing game, including when the project is renamed or presented as an original work. The change was made for Opus 5.5, the model Anthropic launched with lower prices and additional safeguards. The company’s usage policy has been revised more than once this year.
