Anthropic clamps down on Claude’s AI video game clones

AI coding tools have made copying a game dramatically cheaper. Retro titles are being decompiled, recompiled and ported at a pace that used to take teams of volunteers years, and indie developers are watching rough copies of their demos appear almost as soon as they show them.

Anthropic's answer is a small change with a big signal. Claude Code's prompt on Opus 5.5 now steers the model toward original games, genre games and projects built from a user's own designs and assets, and away from recreating a specific existing title. An Anthropic engineer, Addy Osmani, confirmed the change publicly and tied it to the company's usage policy against infringing IP.

This is one of the first times a major model maker has drawn a product-level line around a specific creative category. How it plays out will shape how other labs handle the same pressure.

We think Anthropic is right to draw a line here, and right about where it put the line. Helping someone build a puzzle game is useful. Helping someone ship a near-copy of a game a small studio spent years on is not, and a model maker shouldn't pretend it has no role in that.

But let's be honest about what this is. It's a nudge in a prompt, not a wall. As Ars Technica points out, anyone who wants a clone can switch to a frontier model without the rule, or to an open-weight model that isn't far behind. A single company's guardrail doesn't change the economics of copying much. It mostly changes who is on the hook.

That liability angle is real, and it's probably the main reason this exists. AI companies have already been through legal trouble over generated images that track copyrighted work. A clear written policy, enforced at least partly in the product, is a reasonable defensive move. We don't hold that against Anthropic. We just don't think it should be sold as solving the copying boom.

The harder problem is the line itself. The difference between a recreation of Tetris and a game in the Tetris genre is something courts struggle with. Mashups that drop one franchise's character into another's world are even murkier. Asking a model to make that call in the moment, from two sentences, guarantees mistakes in both directions: some clones get through, and some legitimate projects get refused. Reports on Anthropic's GitHub already suggest the second kind is happening.

I'm watching how Anthropic handles the false positives. Osmani invited people to flag refusals of their own work, which is a good start. If the rule scales across other tools and models without a clear appeal path, the cost lands on honest developers while the people doing the copying just change tools. The thing that would actually help the community is better norms around assets and credit, and no prompt can enforce those.

Game decompilation, reverse-engineering a game's code so it can be rebuilt or ported, has long been a painstaking volunteer craft. Ars reports that decomp.dev, a years-old community hub for that work, shut down last month after its maintainer said AI-driven porting races had broken the community side of the hobby. Decompilation projects generally hold up legally when they leave out expressive elements like art and sound, but there's no guarantee individual users will be that careful.