Anthropic has confirmed that Claude Code was changed to reject requests to recreate someone else’s specific game. The company says using Claude to infringe intellectual property violates its usage policy.

The update follows growing concern among independent developers about AI-assisted game cloning. Some studios fear that releasing a demo could give copycats enough material to reproduce their game and publish a competing version before the original launches.

According to Game Developer, the restriction targets recreations of existing games. Anthropic says original game development, projects within an established genre, and games built from users’ own designs and assets should remain supported.

What Changed in Claude Code’s Game Development Rules

Anthropic added two sentences to Claude Code’s prompt for Opus 5.5, directing the tool away from reproducing specific existing games. Renaming a recreation or describing it as an original project does not put it outside the restriction.

An X user known as Chasm first drew attention to the instruction. The user reported that it appeared around October 27 under the internal flag tengu_heron_brook. Users cannot disable the rule.

An Anthropic spokesperson referred reporters to a statement from a member of the company’s technical staff. That statement connected the prompt change to Anthropic’s existing policy against intellectual property infringement.

The company also said it would keep adjusting the implementation to balance those restrictions with support for original game creation.

Which Game Projects Should Still Be Supported?

Anthropic identified three types of work that are intended to continue functioning:

  • Original games.
  • Games developed within a genre.
  • Games based on a user’s own designs and assets.

The stated distinction is between creating a game and recreating a particular game that already exists. The instruction explicitly addresses attempts to present a recreation as something new through a different name or description.

A Reported Refusal Raises Questions About Licensed Adaptations

One developer at Conflict Simulations LLC reported in a GitHub issue that Claude refused to help with board-wargame adaptations the developer described as licensed. The reason for that refusal remains unclear.

That report leaves an unresolved question about how the restriction handles authorized adaptations. It does not establish whether the new game-recreation instruction caused the refusal.

The restriction also has practical limits. Game Developer noted that carefully worded requests can sometimes get around AI safety controls. People seeking to build clones could also move to open-weight models without equivalent restrictions.

Anthropic’s prompt change therefore addresses Claude Code’s behavior, while the broader concerns about AI-assisted cloning remain.

Game-Cloning Fears Disrupt Public Playtests

PC Gamer connected a recent wave of rapidly produced clones and decompiled games on Steam and Roblox with the release of Claude Opus 5.5.

Those concerns have already affected how some studios share unfinished projects. Digital Sun, the Valencia-based studio behind Moonlighter, canceled a public Steam playtest for ReVamp because of worries about games being reverse-engineered, copied, and released ahead of their originals.

As reported by Video Games Chronicle, Digital Sun replaced the public test with a smaller Discord playtest beginning October 29. The studio hopes to hold a public test around January, ahead of ReVamp’s planned March 25, 2027 launch.

Alliance Arts also held back a planned demo because of cloning concerns.

For Digital Sun, limiting access creates a difficult trade-off. The studio has emphasized that showing games before release helps independent developers gain visibility and find an audience. Its message called on platforms to strengthen protections for original work, according to Time Extension.

Steam Faces Questions About Protecting Original Games

Developers have asked Valve how Steam will prevent clones from crowding out their projects. Valve also gave developers in South Korea an uncommon explanation of its approach amid those concerns.

A GamesIndustry.biz opinion article raised a broader criticism of Steam’s open publishing model, which allows games to launch after payment of a small fee. The piece argued that AI’s ability to make low-quality games cheaply threatens that system’s viability.

That assessment is an opinion about the storefront’s direction. The concrete concern raised by studios is how to promote upcoming games publicly while reducing the chance that a copy appears first.