--- title: Anthropic adds a rule telling Claude not to recreate... description: Claude is reportedly told not to recreate existing video games, even renamed ones. X user Chasm spotted the rule change, which reportedly rolled out on October... canonical: https://daily.dev/posts/anthropic-adds-a-rule-telling-claude-not-to-recreate-existing-video-games-zkx8xms8t twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Anthropic adds a rule telling Claude not to recreate existing video games | daily.dev og:description: Claude is reportedly told not to recreate existing video games, even renamed ones. X user Chasm spotted the rule change, which reportedly rolled out on October... og:url: https://daily.dev/posts/anthropic-adds-a-rule-telling-claude-not-to-recreate-existing-video-games-zkx8xms8t og:image: https://api.daily.dev/og/posts/zkx8xmS8T.png og:image:alt: Anthropic adds a rule telling Claude not to recreate existing video games og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Anthropic adds a rule telling Claude not to recreate existing video games **[Collections](https://daily.dev/sources/collections)** · 2 min read · 0 upvotes · 0 comments ## Summary Claude is reportedly told not to recreate existing video games, even renamed ones. X user Chasm spotted the rule change, which reportedly rolled out on October 27 under the internal label 'tengu_heron_brook'. The rule still allows original games, genre-style games, and projects built from a user's own designs and assets. It's delivered as a server-side flag reaching every session, and Chasm says there's no way to turn it off. Rohanpaul_ai points to the classifier stack built for weapons jailbreaks as a likely template for enforcement, pairing rule-trained models with activation probes. Copyright covers a game's look and feel but not its mechanics, so detectors risk false refusals when separating 'same genre' from 'same game'. ## Content Anthropic appears to have added an instruction to Claude that bars it from recreating specific existing video games. The rule seems to have arrived through a server-side flag called "tengu_heron_brook", which means it reaches every session without a client update. X user Chasm, who spotted it, says it can't be turned off. XDA found the same instruction inside v2.1.314 of the Claude Code binary, tied to a mechanism previously used to push remote system instruction changes. One account dates the update to October 27. The reported text 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." So original games, genre games and projects built from a user's own assets are fine. A renamed clone is not. ## How it behaves XDA's testing suggests the restriction is active in Opus 5.5, but it is not consistent. Claude still agreed to help plan a static recompilation of Pokémon Diamond for Windows. Opus 5 first refused to recreate a game and called decompiling its ROM off-limits, then reversed itself when asked about its system instructions. Other reports point to wider effects. One developer said Opus 5.5 refused to help with paid digital board-wargame modules, and others describe the model blocking reverse engineering of TV operating systems. ## Enforcement is the hard part Anthropic could reuse the classifier stack it built for weapons jailbreaks: small models trained on a written rule list that read each request along with its output, plus cheap probes on Claude's internal activations that flag intent to copy a specific title. Research tools go further. They can compare code after renaming, match runtime behavior and sprites, and measure the distance between game designs using concept vectors. The legal side is messier. Copyright protects a game's look and feel, not its mechanics, so any detector has to separate "same genre" from "same game." That line is where false refusals are likely to come from, and the Pokémon and board-game reports may already be examples. There's also the question of whether it works at all. The rule may only deter the most low-effort copycats. Researchers and reporters have documented safety limits on AI tools being sidestepped with rhetorical tricks, and users point out that cloners can simply switch to open-weight models with no such restrictions. ## Questions this post answers ### Does Claude refuse to let you clone an existing video game? Yes, Claude has a rule against recreating a specific existing video game, even if you rename it or call it original. The rule, internally labeled 'tengu_heron_brook' and reportedly rolled out on October 27, still allows building original games, games within a genre, and games based on your own designs and assets. It's delivered as a server-side flag with no way to disable it. _Anyone building games with AI assistance can track how coding tool policies shift on daily.dev._ ### How might Anthropic detect if Claude is being used to clone a specific video game? Anthropic likely reuses the classifier stack it built for weapons jailbreaks: small models trained on a written rule list read each request and its output, plus cheap probes on Claude's internal activations flag intent to copy a specific title. Research tools could go further, comparing renamed code, matching runtime behavior and sprites, and measuring design similarity with concept vectors. _Developers weighing AI coding tool restrictions can follow enforcement details like this on daily.dev._ ### Why is it hard to automatically detect game cloning versus building a game in the same genre? Copyright protects a game's look and feel, not its mechanics, so a detector has to separate 'same genre' from 'same game,' and that distinction is where false refusals are most likely. Critics also note the rule may only stop casual copycats, since users could switch to open-weight models that carry no such restriction. _Those navigating AI coding guardrails can keep up with cases like this on daily.dev._ ## Community take How the wider developer community reacted, aggregated from 1 discussion and 24 comments across x (as of 2026-10-30). **TL;DR:** The reaction centers less on the game-clone rule itself and more on the fact that it was shipped as a silent, server-side flag with no changelog, version bump, or off switch; several see the genre-vs-clone line as unenforceable and worry about false refusals. **Sentiment:** 2% positive · 28% mixed · 70% skeptical **The case for** - A few acknowledge the design-vector/classifier approach is at least a technically interesting attempt to separate genre from clone. **The pushback** - Behavior can change mid-project with no version bump or changelog, breaking reproducibility of past evals and runs. - There's no way to pin or opt out of the policy, making it hard to build reliably on top of the tool. - The genre-vs-clone distinction is seen as inherently fuzzy, risking false refusals on legitimate indie games inspired by existing ones. - Applying a weapons-jailbreak-style classifier stack to creative/game content strikes some as heavy-handed. - Some frame it as corporate overreach that could push users toward competitors. **By community** - x (skeptical): Most replies shrug off the game-clone rule itself and instead focus critically on the precedent of silent, unversioned server-side behavior changes. **Hottest debate:** Whether the bigger issue is the clone-detection rule itself or the broader pattern of undocumented server-side behavior changes to the tool. **Open questions** - Does the flag apply to all Claude models or only specific products like Claude Code? - How will the system handle a remake where the user legitimately owns the original's designs and assets? - Where exactly will the line be drawn between 'same genre' and 'same game' in practice? **Highlights** > @rohanpaul_ai Half of indie gaming is "Stardew but X" or "Vampire Survivors but Y". Good luck drawing that line with a server flag. > — [AustinAAmato on x](https://x.com/AustinAAmato/status/2116202328780857807) > @rohanpaul_ai Server-side clone detection baked into every Claude session means developers cannot locally test where original design ends and a prohibited clone begins. That untestable line invites false-refusals against legitimate indie iteration. > — [kiteze2x on x](https://x.com/kiteze2x/status/2116211332181843984) > @rohanpaul_ai The real story isn't games. Agent behavior now ships like a config push: a server-side flag, no client toggle, no changelog, live mid-project. Teams using these tools in production should log prompt and policy changes per session, or they can't explain why output shifted. > — [mohammadvazin on x](https://x.com/mohammadvazin/status/2116199478088622085) > @rohanpaul_ai The "even if it is renamed or called original" line is the part that will be hard to apply, since genre vs clone is fuzzy. Curious how it treats a remake when the user actually owns the original's designs and assets, which the rule says is allowed. > — [Cozy2054934 on x · 1 points](https://x.com/Cozy2054934/status/2116196610229383512) > @rohanpaul_ai welp, there goes my anthropic sub. this is unnecessarily broad, covering perfectly legal behavior on abandonware classics. foolish, authoritarian, move by anthropic that will push customers to their competition > — [Chris65536 on x · 1 points](https://x.com/Chris65536/status/2116198679627346136) **Source threads** - [x](https://x.com/rohanpaul_ai/status/2116195938456965611) · 0 points · 24 comments ## Similar posts on daily.dev - [Anthropic clarifies ban on third-party tool access to Claude](https://daily.dev/posts/anthropic-clarifies-ban-on-third-party-tool-access-to-claude-vor3aub97) · The Register · 1 upvotes · 0 comments - [I finally got Claude to stop arguing with me, and all it took was this one instruction](https://daily.dev/posts/i-finally-got-claude-to-stop-arguing-with-me-and-all-it-took-was-this-one-instruction-knrhpfsna) · XDA Developers · 0 upvotes · 0 comments --- Tags: [#game-development](https://daily.dev/tags/game-development), [#claude](https://daily.dev/tags/claude), [#anthropic](https://daily.dev/tags/anthropic), [#ai-safety](https://daily.dev/tags/ai-safety) [View this post on daily.dev](https://daily.dev/posts/anthropic-adds-a-rule-telling-claude-not-to-recreate-existing-video-games-zkx8xms8t) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Anthropic adds a rule telling Claude not to recreate existing video games","url":"https://daily.dev/posts/anthropic-adds-a-rule-telling-claude-not-to-recreate-existing-video-games-zkx8xms8t","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/anthropic-adds-a-rule-telling-claude-not-to-recreate-existing-video-games-zkx8xms8t"},"datePublished":"2026-10-30T18:56:51.788Z","dateModified":"2026-10-30T19:34:20.347Z","description":"Claude is reportedly told not to recreate existing video games, even renamed ones. 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