Late last week, Anthropic inserted a new instruction into Claude Code’s Opus 5.5 prompt aimed at stopping direct recreations of existing video games. The rule allowed original titles, genre games and projects built with users’ own assets, while barring a recreation of a specific game “even if it is renamed or called original.”¹

The company’s rationale was straightforward: avoid turning a coding assistant into an engine for infringement. Addy Osmani, an Anthropic software engineer, said the company had added the language to steer Claude away from copying specific games because using the tool to infringe IP violates its policy. He stressed that original games and genre-based projects were still meant to work.Addy Osmani (addyosmani)²

But the first version of the guardrail proved too blunt. Developers found Claude could reject projects that merely named an existing game to explain the mechanics they wanted. Anthropic then updated the rule in version 2.1.317: users can now cite a game as an example, and Claude should build an original game in that genre; requests for a straight copy should instead receive an offer to make something similar.³

That revision addresses the immediate usability problem, but not the broader one. Critics of the policy argue that Claude’s restriction may reduce Anthropic’s legal exposure while doing little to slow AI-assisted ports, decompilations and knockoffs. Would-be copiers can turn to competing models or open-weight alternatives, while Claude still faces a notoriously murky distinction between a prohibited clone and a permissible genre homage.¹

The episode leaves Anthropic defending a practical compromise: block explicit copying, permit inspiration. The harder question is whether any short system prompt can reliably police that boundary as AI makes game replication faster and cheaper.