Claude Code now refuses to rebuild existing games, and some indie developers say it overreaches

A short rule with a long reach

Anthropic has told Claude Code, its tool for writing software with AI, not to recreate specific existing video games. As International Business Times UK reported, users noticed the change around 27 October in the instructions that Claude Code feeds to Anthropic's Claude Opus 5.5 model.

The instruction runs just two sentences. It points Claude toward building original games, games within an established genre, and projects built on a user's own designs and assets. It rules out copying one particular title, and it says that renaming the project or describing it as original does not change that.

Anthropic's stated reason is intellectual property. Using Claude to infringe someone else's rights breaks the company's usage policy, and the new line is meant to enforce that for games.

How the rule arrives on your machine

Claude Code works by sending the AI model a block of background instructions, called a system prompt, along with whatever the user types. Users never see most of it, but Anthropic can change it. Here the instruction is delivered from Anthropic's servers rather than through an app update, so nothing has to be installed for it to take effect.

Users who dug into the configuration found a flag named 'tengu_heron_brook' tied to it. They report there is no setting on their own computers to turn it off.

Addy Osmani, who works on Anthropic's technical staff, confirmed the addition on 30 October. He said original games and projects using a person's own designs and assets should keep working. He also invited anyone hit by a mistaken refusal to contact him directly.

The board-game modules complaint

The most detailed objection comes from the operator of Conflict Simulations LLC, which makes personalised digital versions of board wargames for individual clients. In a GitHub issue filed on 30 October, the developer said Claude Code began turning down work it had handled for months. The code is written from scratch, the developer said, and clients supply materials from physical games they own. The modules are for private use, not public release.

The developer first called the work licensed, then corrected that, admitting the publishers had not authorised it. That matters. Buying a physical game does not give you the right to copy or adapt its artwork, text or other protected content. The complaint is one person's account of lost paid work. It does not show that rights holders approved the projects.

The developer also described a frustrating support experience. Anthropic's automated support first said the rule applied without exceptions. The matter was then passed to human staff and a formal appeal was filed.

Why game makers are on edge

The restriction lands while small studios worry about AI-assisted copying. Alliance Arts, an independent publisher, called off the public release of a demo of Drunken Goddess Reflux that had been set for 19 October. It announced the cancellation on 16 October. The studio cited trouble controlling gameplay videos and streaming, and worry that the demo could be used to make AI-assisted imitations.

The studio did not say any copy of its game already existed. The article presents the move as caution about showing an unfinished game in public, and as a sign that smaller developers are thinking harder about how they show and share unreleased work.

What nobody has explained yet

The hard part is the gray zone. A game in a familiar genre is allowed, while a copy of one specific game is not, but plenty of projects sit between the two. Anthropic has not published how Claude Code decides where a request falls.

It has also not shared how often the instruction triggers refusals, or how many of those involve projects that were never trying to copy anything. Osmani's offer to review mistaken blocks is a start, but Anthropic has not described any formal way to verify commissioned work, such as paperwork showing permission from a rights holder.

Our own practical suggestions, not Anthropic's: describe your project's design in your own words, keep any commission or licensing paperwork handy, and store your code in version control so a refusal never costs you progress. None of this is a way around the rule. A true clone is what the rule targets.