Anthropic Blocks AI Game Clones in Claude Opus Update

Anthropic has issued an update for Claude that puts a stop to the AI-generated game clones that have filled platforms like Steam.

The term 'AI slop' is something we've heard a lot in the past few years, but it became especially prevalent in the gaming community after Valve launched Steam Next Fest earlier this month. PC users quickly launched complaints that their feeds had been filled with low-effort clones not only of pre-existing games but even some titles that had only just released their own demos.

As players trudged through the slop, developers faced a reality that threw months or even years of hard work into jeopardy. Some, including Drunken Goddess Reflux developer Alliance Arts and Who You, even took action by canceling their Steam demo plans in favor of private playtests. It's a situation that rapidly spun out of control, prompting a response from Valve itself as it said it would be "thinking about how to solve this problem."

ANTHROPIC IS CRACKING DOWN ON VIDEO GAME REWRITES 🚨Claude Code picked up a new rule around Oct 27, sent from Anthropic’s servers under a flag called "tengu_heron_brook". There’s no setting to turn it off.The full rule: “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.”Is this the end of game rewrites, modding and everything in between?— chasm (@chasmmmmmmmmmmm) October 30, 2026

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ANTHROPIC IS CRACKING DOWN ON VIDEO GAME REWRITES 🚨Claude Code picked up a new rule around Oct 27, sent from Anthropic’s servers under a flag called "tengu_heron_brook". There’s no setting to turn it off.The full rule: “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.”Is this the end of game rewrites, modding and everything in between?

As reported by Game Developer, X/Twitter user Chasm was one of the first to share evidence of tech company Anthropic taking action against video game copycats. Based on their findings, Claude, the company's AI assistant, recently received an update featuring a new rule. The full rule can be read below:

"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."

When reached for comment by Game Developer, Anthropic pointed to a post shared by Addy Osmani, a member of its technical staff. Osmani's explanation can be read below:

"We added two sentences to Claude Code's prompt on Opus 5.5 to steer it away from recreating someone else's specific game because using Claude to infringe IP is against our usage 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. In the meantime, if Claude turns down something that's yours, send it my way."

Whether there was a specific event or reason that prompted Anthropic to make these changes is unclear.

Game developers and game enjoyers will no doubt find comfort in Anthropic's changes, though it's worth noting that how impactful any of this will be remains to be seen. At the very least, those who use Claude to rip ideas directly from those who used their minds and time to bring them to life should have a tougher time trying to profit off of the work of others.

The industry is struggling to come to grips with artificial intelligence. Some, such as Epic Games' Tim Sweeney, have insisted that Valve should stray from asking developers to disclose games utilizing generative AI materials. Others, including Super Smash Bros. mastermind Masahiro Sakurai, have compared AI-generated games to "low-quality goods." The developers behind VRChat, meanwhile, recently came under fire for how they are handling AI content.

Getty Images credit: Kenneth Cheung.