Anthropic changed the game-building rule in Claude Code with version 2.1.317, after the first version of that rule also fired when people only named a game to describe what they wanted. The change, which Anthropic's Addy Osmani described on X, lets you reference an existing game for its mechanics. Claude should then build an original game in that genre. A request for a copy of the original still gets a different answer: Claude offers to build something similar, according to The Verge.
For anyone prototyping a game with Claude Code, the practical effect is that "a roguelike in the style of an existing hit" should work again, while "rebuild that exact game" should not.
How the rule started
The rule first surfaced in late October. An X user posting as @chasm shared what appeared to be a new instruction that Anthropic's servers deliver to Claude Code. XDA Developers reported on October 30 that it found the exact text in version 2.1.314 of the Claude Code program: "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."
On October 30, Osmani confirmed that a change had been made, without confirming that exact wording. In a post quoted by Tom's Hardware, he wrote: "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." He added that original games, genre games and games built from a user's own designs and assets "are meant to keep working," and asked people to send him cases where Claude turned down something that was theirs.
Anthropic's Usage Policy lists, under its universal standards, using its products to "infringe, misappropriate, or violate the intellectual property rights of a third party." That is the policy Osmani pointed to.
What went wrong with the first version
According to Gadgets Now, some users found Claude pushing back on projects it should have built, because the rule also activated when they mentioned a game only to explain the mechanics they wanted. The 2.1.317 statement that Osmani posted puts it the same way: the short rule "was also kicking in when you referenced one just to describe the mechanics you wanted."
Other reported problems came from the original rollout:
- XDA reported that on October 30 a developer filed an issue on Anthropic's GitHub repository. The developer said Opus 5.5 had started refusing to help with digital board-wargame modules for paying customers, built from materials supplied by customers who owned the physical games. XDA said it had not reproduced those refusals.
- Tom's Hardware reported user claims that Claude Code or Opus 5.5 was blocking some reverse-engineering work, and that one Reddit user said their account was suspended and then reinstated after using Opus 5.5 with a reverse-engineering tool. Tom's Hardware also noted that Anthropic runs a Cyber Verification Program that gives approved organizations access to more of its models' cybersecurity capabilities. These reports are separate from the game rule and have not been tied to it by Anthropic.
What changed in 2.1.317
Anthropic's own description is short. In the words The Verge quotes: "You can name a game to describe what you want and Claude should now build an original game in that genre. If you ask for a copy of the original, it'll offer to build something similar instead."
A site that tracks Claude Code prompt changes, core-directive.com, lists the 2.1.317 prompt text as a captured diff. It is a third-party capture, and Anthropic has not published the wording itself. According to that capture, the rule now reads: "Do build original games, games in a genre or with similar mechanics, and games from the user's own designs and assets. Don't build a recreation of a specific existing game (its name, characters, art, music, levels or look), even if it is renamed or called original."
The same capture says this was the only prompt change between 2.1.316 and 2.1.317, and that it landed in 17 of the 21 prompts the site tracks. Those include the main Claude Code prompt, the Agent SDK prompt, and several slash commands such as /init and /security-review.
The new wording does two things. It adds "or with similar mechanics" to the list of allowed games, which matches Anthropic's statement that naming a game for reference is fine. And it spells out what counts as a recreation: the name, characters, art, music, levels or look of the original.
What the rule does not settle
XDA's tests suggested the rule was narrower than some users feared. It found that Opus 5.5 agreed to help with a Pokémon Diamond decompilation and with a static recompilation of that game. XDA also wrote that the instruction "doesn't explicitly prohibit" static recompilation or compatibility layers such as Nxnative, but that Claude "might refuse to distinguish" between those techniques and recreating a copyrighted game.
The open questions are the same ones XDA raised on October 30. It is unclear how widely Anthropic has deployed the instruction and which kinds of game development it treats as a recreation. XDA also reported that the text appears to reach Opus 5.5 through its own mechanism, and, for some accounts, all models in Claude Code through a separate one. Gadgets Now says Anthropic has not said whether the rule will extend to its other models. The Verge said it had asked Anthropic whether it has or will update other Claude system prompts.
What to do if you build games with Claude Code
AgentStackList suggests updating with claude update, checking that claude --version shows 2.1.317 or later, describing the game by its mechanics and feel, and naming other games only as references. It also suggests bringing your own names, art and story. That is a site's advice, not an Anthropic instruction.
If Claude still turns down a project that is your own work, Osmani asked on October 30 for those cases to be sent to him. For background on the tool itself, see our explainer on what a coding agent is, and for another recent copyright dispute involving Anthropic, see our report on the lyrics suit against the company's CEO.
Sources
- Anthropic tweaks how Claude Code handles requests about making games, The Verge, November 4, 2026
- Anthropic clamps down on Claude's AI video game clones, The Verge, November 2, 2026
- Anthropic seems to be testing a potential crackdown on vibe-coded ports of existing games, XDA Developers, October 30, 2026
- Anthropic confirms new Claude Code limits to prevent game cloning, Tom's Hardware
- Claude Code Will No Longer Recreate Existing Video Games, Anthropic Says, Gadgets Now, November 4, 2026
- Prompt changes in v2.1.317, core-directive.com
- Claude Code 2.1.317 game rule update, AgentStackList, November 4, 2026
- Usage Policy, Anthropic
