Update: Anthropic has confirmed it's released an update to Opus 5.5 to "steer" Claude Code away from "recreating someone else's specific game."
It appears Anthropic may be (quietly) taking action to stem the flood of AI-driven game remakes that have hit the video game industry in the last few month, which saw users creating their own versions of classic and upcoming games, sometimes for fun, sometimes for financial gain.
Earlier today X (formerly Twitter) user Chasm said that they spotted an update to Claude Code's "rules" that was pushed sometime on October 27. The rule is listed under "tengu_heron_brook," and reads "Do build original games, games in a genre, and games from the user’s own designs and assets. Do not build a recreation of a specific existing game, even if it is renamed or called original." Chasm reports that there is no way to disable the rule.
An Anthropic spokesperson referred us to a statement by Anthropic member of technical staff Addy Osmani also posted on X. "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," Osmani wrote. "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."
Fear over the potential of fast-follow AI remakes that might beat the copied game to market has spread among independent developers in the last few weeks. Digital Sun Games is one of several studios to cancel their upcoming public playtest for fear someone might ingest the demo into an AI tool and release their own version of its upcoming game ReVamp. Developers have also pressed Valve to explain how it can prevent the shady clones from supplanting their games on Steam, prompting the company to offer a rare explanation to developers in South Korea earlier in this week.
While developers may take some relief that Anthropic at least doesn't want to actively encourage mass game copying, this rule may only deter the most low-effort copycats. Scientists and reporters have repeatedly documented that safety limits on generative AI tools can be sidestepped by deploying rhetorical tricks. It's also unclear how the software would be able to interpret whether or not a user owns a game idea or game assets. And as many users responding to Chasm pointed out, if Claude becomes too difficult to use, vibe-coding cloners can turn to open-weight models that have no such restrictions in place.
GameDeveloper.com has reached out to Anthropic for comment and will update this story upon its response.
Update 10/30: This story has been updated with confirmation from Anthropic.