Addy Osmani, an Anthropic employee, wrote on X on 4 November that the company had fixed a Claude Code rule on games. The Korean outlet AI Times reported the change, based on Osmani’s update.

‘Last week some of you ran into Claude Code pushing back on game projects it should have just built,’ Osmani wrote. Claude Code is Anthropic’s coding agent that runs in the terminal.

What the rule was and what changed

In late October, Anthropic added a short rule to the system prompt of Claude Opus 5.5. A system prompt is the instruction a model receives before the user’s request.

The Chinese outlet 36kr published an ifanr article reporting that a developer called chasm had found the rule in Claude Code’s settings. The rule allowed Claude to help build original games, games in familiar genres, and games based on the user’s own designs and assets. It did not allow Claude to recreate a specific existing game, even under a new name.

However, the rule was also triggered when a user mentioned a well-known game only to describe what they wanted. Developers complained that the ban also blocked some software analysis and reverse-engineering tasks, AI Times reported. Claude could, for example, refuse to analyse harmless decompiled code, 36kr wrote.

Osmani said the rule had changed in version 2.1.317, AI Times reported. Users can now name an existing game to describe what they want, and Claude will make an original game in the same genre. If a user asks directly for a copy, Claude offers to make a new game in a similar style.

So the copying ban has not been lifted. AI Times reported that a new game may borrow, for example, a combat or movement system. Reproducing the original game’s structure and content remains restricted. The sources do not say whether the obstacles to reverse engineering were removed.

Osmani aims to help people who make their own games as much as possible and to protect their work if someone else tries to copy it, AI Times reported.

36kr: games are already being copied with AI

Osmani confirmed that the rule was added to prevent intellectual property infringement, 36kr reported. The article describes cases in which independent developers’ games were copied with AI before they were even released. The imitator of the game Typing Magician admitted feeding the creator’s development videos into AI, the Japanese outlet AUTOMATON reported.

The article’s author sees the restriction as a late patch that is unlikely to solve the problem thoroughly. Copyright protects code, graphics and sound but not game mechanics or rules, the article says.