Claude Code 2.1.317 rewrites its game rule: "similar mechanics" are now allowed, "recreation" is spelled out, and the changelog says nothing

Anthropic has rewritten the rule in Claude Code that tells Opus 5.5 not to rebuild existing games. Addy Osmani, who works on Claude Code at Anthropic, announced it on November 4. The rule had been "kicking in when you referenced one just to describe the mechanics you wanted," he wrote, and "we've updated that rule in 2.1.317. 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."

We covered the original rule on November 1, along with the remote prompt slot, tengu_heron_brook, that first delivered it. At the time Osmani had promised to "continue to iterate." Here is what the iteration looks like.

The two versions, side by side

We downloaded the Linux x64 builds of Claude Code 2.1.316, 2.1.317 and 2.1.318 from npm and pulled the rule's text out of each binary with strings. 2.1.316 still has the wording we quoted last week. 2.1.317 and 2.1.318 have this:

- 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.
+ 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 change cuts both ways. The first sentence now explicitly allows "similar mechanics," which is the false-positive case Osmani describes. The second sentence spells out what a recreation is: a game's "name, characters, art, music, levels or look." Tech AI Wire found the same text in the app a day before Osmani's post and headlined it as a widening. Osmani presents it as a loosening. Both readings fit the diff. Mechanics are now plainly fine. "Look" is broad enough that a game that merely resembles another one could still trip the rule.

The behavior Osmani describes for outright copies, offering "something similar instead," isn't in the text. It's what Anthropic expects Opus 5.5 to do with it.

Not in the release notes

2.1.317 reached npm on November 2 at 23:57 UTC. Its GitHub release notes run to dozens of entries, from a /schedule warning about unrequested connectors to new OTel attributes, and none of them is about games or the system prompt. The 2.1.314 notes didn't mention the rule when it arrived, and the 2.1.318 notes don't either. So the one place Anthropic documents Claude Code changes has now skipped a behavior-changing prompt edit twice. Users found out from a binary dump and a post on X.

The server route

There is a wrinkle for accounts that get the rule from Anthropic's servers rather than from the app. The 2.1.317 code adds its built-in games section only if the text served through tengu_heron_brook doesn't already contain the opening words "Do build original games, games in a genre". Old and new versions both start with those words. If an account is still being served the old text, the new built-in wording is skipped and the old rule stays in place. That is our reading of minified code. We can't see what Anthropic's servers send to any given account today. If they still send the old sentence, updating to 2.1.317 won't change anything for those users until Anthropic edits the flag.

The case that hasn't moved

The new text doesn't address the most concrete complaint so far. In issue #106167, lerugray of Conflict Simulations LLC describes paid work building digital modules of board wargames for clients who own the physical games. Under the new definition that is still a recreation of a specific game's name, art and look. As of November 4, 09:00 UTC, the issue has no reply from Anthropic. Its latest comment, from November 2, is a user announcing they will cancel their Max subscription over the rule. lerugray posted under Osmani's update that it was "Day 6 of asking" for the help Osmani offered publicly, and "still no reply."

People who named a game only to describe its mechanics should see fewer refusals after updating. People whose work is an authorized copy have no exemption path yet. Anthropic's version history still won't show them when the rule changes.