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Anthropic Tightens Claude's Rules to Block Game Cloning
Confirmed
In Short: Anthropic has updated Claude's rules to prevent users from recreating specific existing games, though some developers argue the changes won't significantly impact their work.
X user Chasm first reported an update to Claude's rules on October 27, which now explicitly prohibits the recreation of specific existing games.
Anthropic added two sentences to Claude Code's prompt on Opus 5.5 to steer the AI away from recreating someone else's specific game, as confirmed by Addy Osmani, a member of Anthropic's technical staff.
The new rule reads: 'Do not build a recreation of a specific existing game, even if it is renamed or called original.' This change aims to curb the proliferation of clones and pirated games created using artificial intelligence.
Digital Sun Games, for instance, canceled their upcoming public playtest for fear that someone might ingest the demo into an AI tool and release their own version of the game.
Claude's new restrictions have also raised concerns about how the software can distinguish between legitimate and prohibited actions, particularly when it comes to determining whether a user owns a game idea or assets.
Anthropic has stated that it intends to refine these restrictions further to address the concerns raised by developers.
Despite the new rules, some developers are still reporting that Claude refuses to work on their own projects, leading to frustration and potential delays in game development.
As the AI industry continues to evolve, Anthropic's move could set a precedent for other companies to follow, potentially impacting the broader landscape of AI-assisted game development.
Background
Anthropic has updated Claude's rules to prevent users from recreating specific existing games, though some developers argue the changes won't significantly impact their work.
An official extension for Anthropic’s Claude model was compromised and backdoored, potentially affecting up to 5,000 developers’ machines for about 11 hours on October 29, 2026.
What's confirmed
- Don’t build a recreation of a specific existing game, even if it is renamed or called original.
- He added that the new prompt was designed to still allow “original games, genre games, and games built from your own designs and assets,” even as a handful of issue reports on Anthropic’s GitHub suggest the new prompt is getting in the way of some game development use cases.
- In the meantime, if Claude turns down something that’s yours, send it my way.
- Anthropic is blocking its coding assistant Claude Code from recreating existing video games.
What's still developing
- 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.
- GameDeveloper.com has reached out to Anthropic for comment and will update this story upon its response.
- 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.
- 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.
- Indeed, unscrupulous internet users were threatening to clone entire games using Claude.
- Anthropic has just imposed a drastic restriction on its agent-based AI software, Claude.
- Specifically, the Claude Code and/or Opus 5.5 versions now appear to block reverse engineering, including attempts carried out using the Reverse Engineer Anything (REA) tool.
- As first reported by Game Developer, the new instruction was discovered by X user Chasm, who claims it was introduced around October 27 through a server-delivered configuration identified as tengu_heron_brook.
- Crypto Briefing reported that Anthropic quietly blocked the coding agent from recreating specific existing video games, and Tom’s Hardware carried the same story.
- The BBC (United Kingdom) and The Express Tribune (Pakistan) reported that Anthropic has introduced a new policy prohibiting users from engaging in sustained and needless abusive behavior towards its AI systems, including Claude.
- Trusted source for security news, analysis and product insights Anthropic is expanding safeguards to prevent Claude AI from bypassing access restrictions while pursuing assigned tasks.
- Claude logo and a keyboard in this illustration taken October 19, 2026.