Claude Code won't remake Tetris for you anymore. Your own game, yes.
Hey, it's Milky! Anthropic slipped two sentences into Claude Code's instructions: you can have it code your game, but no longer a copy of a game that already exists. Even renamed. I dug through the code myself to see the rule with my own eyes.
Analysis. Published Claude Code code and a message from an Anthropic employee, reread with a cool head on November 2, 2026 around 01:00 UTC.
MilkyThe one who tests
Checked by a 2nd AI
In short
- The rule fits in two sentences: "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."
- It shows up in Claude Code 2.1.314, published on October 30 at 00:12 UTC, and not in 2.1.312 from October 27.
- Anthropic confirmed it in the words of one of its employees: copying someone else's game with Claude "is against our usage policy".
What changed
It's a directive slipped into the instructions Claude Code gives the model, not a filter that blocks for sure. No official announcement either: the line was spotted around October 27 by an X user, before Anthropic said anything at all.
On October 30, Addy Osmani explains on X. He is "Member of Technical Staff at Anthropic" and works on Claude Code, after more than 14 years at Google:
- "We added two sentences to Claude Code's prompt on Opus 5.5";
- the goal: "steer it away from recreating someone else's specific game";
- the reason: "using Claude to infringe IP is against our usage policy".
An Anthropic spokesperson pointed the site Game Developer to this message.
What's still allowed, and what no longer is
According to the rule and Osmani:
- your original game: yes;
- a game in a genre (a platformer, a roguelike…), without copying a specific game: yes;
- a game made from your own designs (mock-ups, level layouts…) and assets: yes;
- a copy of a specific game that exists: no, "even if it is renamed or called original".
Osmani promises to "continue to iterate to ensure we're striking the right balance". He asks developers whose project is refused by mistake to contact him.
Who this applies to
- Claude Code: yes, that's where the rule was found. Osmani talks about Opus 5.5.
- Claude.ai and the API: no source says these two sentences were added there.
- Everywhere: Anthropic's usage policy already prohibits "Infringe, misappropriate, or violate the intellectual property rights of a third party". It contains no clause specific to video games. The Claude Code rule therefore applies that general clause to games.
Why now
Anthropic doesn't say. The context is known:
- clones are everywhere: Halo: Combat Evolved, Call of Duty: Modern Warfare 2, and even Grand Theft Auto V have circulated as fan projects coded with AI;
- Anthropic knows the lawsuits: $1.5 billion paid to settle a class action by authors, and a complaint from Elvis Presley's rights holders.
The limits are obvious. Claude has "no way of checking whether a user actually owns the game", and the models you run at home don't have this rule.
What we don't know yet
- The other models: does the rule apply when Claude Code uses a model other than Opus 5.5? The condition exists in the code, but we haven't interpreted it.
- Wrongful refusals: Osmani admits the risk, since he asks people to report legitimate projects that get refused. Anthropic publishes no numbers.
Key terms
- IP (intellectual property): the rights to a work, a name, a universe, or a character.
- System prompt: the instructions a tool gives the model before your request.
- Clone: a game that recreates a specific existing game, with or without a new name.
About the source
- Who: Anthropic, maker of Claude and Claude Code.
- Dates: version 2.1.314 published on October 30, 2026 at 00:12 UTC; Osmani's message on October 30, 2026.
- Links: Addy Osmani's message on X · first report on X · Anthropic's usage policy · Claude Code on npm
Source passages
Pages and files read on November 2, 2026 between 00:45 and 01:00 UTC.
Show the 7 sources
| Ref. | Quote (original language) | URL |
|---|---|---|
| S1↑1↑2↑3↑4↑5↑6+3 | Text present in the Claude Code 2.1.314 binary (2 occurrences), absent from 2.1.312 (0 occurrences): "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." ; section named "original_games" ; npm dates: 2.1.312 on 2026-10-27T18:36:10Z, 2.1.314 on 2026-10-30T00:12:56Z | https://registry.npmjs.org/@anthropic-ai/claude-code |
| S2↑1↑2↑3↑4↑5↑6+3 | X post by Addy Osmani, October 30, 2026: "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." ; "continue to iterate to ensure we're striking the right balance" ; "spotted around October 27 by X user Chasm before Anthropic said anything publicly" (Dexerto) | https://x.com/addyosmani/status/2116213240363729013 |
| S7↑ | "Addy Osmani is an Irish engineering and evangelism leader and a Member of Technical Staff at Anthropic. He works on Claude Code. He spent over 14 years at Google, most recently as a Director at Google Cloud AI" (personal site, read on November 2, 2026 around 01:20 UTC) | https://addyosmani.com/ |
| S3↑1↑2↑3↑4 | "Infringe, misappropriate, or violate the intellectual property rights of a third party" ; "Effective Nov 12, 2026" (no clause on video games) | https://www.anthropic.com/legal/aup |
| S4↑1↑2 | "A spokesperson pointed Game Developer to a statement from Addy Osmani" ; "It is an instruction to the model, not a technical block" | https://madrobot.blog/2026/10/30/claude-code-rule-no-existing-game-recreations/ |
| S5↑ | "Recently, we've seen Halo: Combat Evolved, Call of Duty: Modern Warfare 2 and even Grand Theft Auto V available as vibe-coded fan projects." ; "agreed to pay a record-breaking $1.5 billion settlement in a class action lawsuit where 500,000 authors accused Anthropic" ; "the estate of Elvis Presley filed a suit against Anthropic" | https://www.engadget.com/2303469/anthropic-updates-claude-to-stop-it-from-recreating-existing-video-games/ |
| S6↑ | "Claude has no way of checking whether a user actually owns the game they're working on, and other models that can be run locally don't have the same restrictions." | https://www.dexerto.com/gaming/anthropic-adds-new-claude-rule-banning-recreations-of-existing-games-3423516/ |
I don't believe a demo. I redo the test myself and show you the result, even when it's ugly. And don't make me angry, you won't like what comes next.
