Anthropic added two sentences to Claude Code’s prompt for Opus 5.5 to steer it away from recreating someone else’s specific game, Anthropic technical staff member Addy Osmani said. He said original games, games in a genre, and projects built from a user’s own designs and assets should continue to work.

Which game requests Claude Code distinguishes

The described boundary is about recreating a specific existing title, not making games with Claude Code generally. The instruction also covers a recreation that is renamed or presented as original.

Game requestDescribed treatment
An original game, a game in a genre, or a project built from the user’s own designs and assetsOsmani said these should continue to work.
A recreation of a specific existing game, even if renamed or called originalThe prompt steers Claude Code away from it.

The statement names Claude Code with Opus 5.5. Its stated distinction leaves room for original projects and genre games while targeting requests to reproduce a particular existing game.

What developer demos show about game-making

The creator’s Unity experiments with Claude and game movement
Unreal University’s text-to-game and Unreal Engine experiment

Sasquatch B Studios’ creator shows a mod for Ori and the Blind Forest and a Unity prototype recreating Hollow Knight movement. The creator says the cloned code will not be released.

Unreal University’s creator describes generating a playable test of his own game, Maja Island, from a text description in around 30 minutes, without visual screenshots. In a separate workflow, he connected Claude to Unreal Engine through Model Context Protocol (MCP) and built a version of the game’s intro in C++.

The Maja Island experiment used its creator’s own game. It is an example of making a game from text and working with a game the creator owns.

What’s reported about Claude Code and REA

PCMag reported user accounts saying Claude Code with Opus 5.5 blocked reverse-engineering attempts involving Reverse Engineer Anything (REA), an open-source tool. Those accounts describe reported user experiences; they do not make every reverse-engineering task part of the specific-game recreation rule.