Claude Code Just Got A New Rule: Stop Copying Other People’s Games

AI clones and vibe-coded copycat games have become a huge headache for developers recently, but it looks like an update to Anthropic’s Claude Code’s “rules” has been pushed out. Listed under “tengu_heron_brook,” the tweak to the AI now directs it not to copy games and assets, and users cannot disable this setting.

Spotted by Chasm on X (via Game Developer), the full rule reads, “Do build original games, games in a genre, and games from the user’s own designs and assets. Don’t build a recreation of a specific existing game, even if it is renamed or called original”. Anthropic’s Addy Osmani added that “two sentences” were added to Claude Code’s prompt on Opus 5.5, to steer it away from recreating someone else’s specific game, as “using Claude to infringe IP ” is against the company’s policy. “Original games, genre games, and games built from your own designs and assets are meant to keep working. We’ll continue to iterate to ensure we’re striking the right balance.”

AI clones have been running rampant for months now, as the tools have let pretty much anyone crank out copies of successful games in surprisingly little time compared to traditional methods of cloning a successful piece of work. This all came to a head during Steam Next Fest last month, when the demo showcase was flooded with low-effort games and AI slop. This has also led several developers to cancel demos outright, fearing bad actors could take the code, whip up a copy in Claude, and release it before their game ships.

Valve has vaguely mentioned that it’s “aware of the situation” and that “a significant number of people are thinking about how to solve” the problem. At the same time, Valve has encouraged developers to focus on building communities and support for games, which isn’t exactly an ideal solution. Creating a community around a game takes time, whereas AI slop clones can be generated fast enough to capitalize on virality, and in an ideal situation, make a quick buck for the prompter on the other end–just look at all the video games about needles in haystacks that have popped up recently, copying the viral success of Needle in a Haystack Simulator, which isn’t out yet.

The rampant reverse-engineering got so bad that the creator behind Needle in a Haystack Simulator, NasNakarus, poked fun at it by teasing a joke mode for the game where players will have to sift through piles of cloned games to find the original.

While tweaking Claude is good news, it doesn’t mean developers are out of the woods yet. Claude prompters will likely look for ways to work around the new restrictions, and if they’re unsuccessful, other AI agents are available without the same safeguards.