What changed
Anthropic introduced a new system prompt for its Claude models, specifically targeting the recreation of specific existing video games. The update, part of the Claude Code prompt on Opus 5.5, includes a rule that explicitly prohibits building a recreation of a specific existing game, even if it is renamed or called original. The rule was added on or around October 27, 2026, and was verified in version 2.1.314 of the Claude Code binary released on October 30.
What this means in practice
The new rule aims to align with Anthropic’s usage policy against intellectual property infringement. It allows the creation of original games, games within a genre, and games built from the user’s own designs and assets. However, some developers have reported issues with the new prompt interfering with game development use cases. Anthropic’s software engineer Addy Osmani acknowledged these concerns and stated the company would continue to iterate to find the right balance. The prompt may offer legal protection for Anthropic against potential liability for copyright infringement in AI-generated game projects.
Limitations and availability
The new rule is part of the system prompt for Opus 5.5 and is included in the Claude Code binary. While it may help protect Anthropic from legal risks, it is unlikely to significantly impact the broader trend of AI-assisted game copying. Developers can still use other models that do not have such restrictions. The supplied announcement does not specify whether the rule is available in all versions of the Claude models or if it applies to all use cases.
