Anthropic has quietly drawn a line around what Claude Code will build for game developers. The AI coding tool is now instructed not to recreate specific existing video games, a change that arrives as indie studios grow increasingly anxious about AI-assisted clones appearing before their own games reach launch.
The rule was first noticed on October 30 by an X user called Chasm, who found a new entry in Claude Code’s rules that had been pushed on October 27. It steers the tool towards original games, genre projects and games built from a user’s own designs and assets, while explicitly blocking recreations of a particular existing title. Crucially, renaming the project or labelling it as original doesn’t get around it, which closes off the most obvious workaround. According to Chasm, the behaviour can’t be disabled.
Anthropic didn’t make a formal announcement. Instead, the company pointed to a post from Addy Osmani, a member of its technical staff, who explained that two sentences had been added to Claude Code’s prompt on Opus 5.5 to discourage it from rebuilding someone else’s specific game. His reasoning was simple: using Claude to infringe intellectual property already breaks Anthropic’s usage policy. He also said the company will keep adjusting the approach to get the balance right, an acknowledgement that the line won’t always be easy to draw.
The timing isn’t accidental. Digital Sun Games recently cancelled the public playtest for its upcoming game ReVamp, fearing someone could feed the demo into an AI tool and release a copy first. The developer of Drunken Goddess Reflux made the same decision, with both studios moving to smaller private tests. Developers have also been pressing Valve on how it will stop clones from crowding out original work on Steam. At the Steam Indie Connect event in Busan on October 27, Valve representatives acknowledged the concern but announced no new rules and said they don’t want to dictate which tools developers use.
That makes Anthropic’s change the first concrete step from an AI company itself, though its real impact is debatable. Safeguards on generative AI tools have a long history of being bypassed with clever prompting, and it’s unclear how Claude can verify whether a user actually owns a game concept or its assets. Anyone determined to clone a game can also turn to open-weight models with no such restrictions.
The grey areas are where this gets interesting. Fan projects, homages and games that borrow heavily from a single inspiration could fall on either side of the rule. Whether Anthropic can stop copycats without frustrating legitimate creators will decide if this becomes an industry standard or just a speed bump.
