Anthropic Updates Claude Code to Prevent Re-Creation of Existing Video Games

What Is New

Anthropic has implemented updates to the system prompt for its Claude Code tool to prevent the AI from being used to recreate specific, existing video games [1, 2]. According to software engineer Addy Osmani, the company added two sentences to the prompt on the Opus 5.5 model to steer the tool away from recreating someone else’s specific game [1, 2]. This change is intended to align the tool with Anthropic’s usage policy, which prohibits using Claude to infringe on intellectual property (IP) [1, 2].

Key details regarding this update include:

• A social media user named “chasm” reported the prompt change around October 27, 2026 [2].
• XDA verified the new rule appears in version 2.1.314 of the Claude Code binary, which was released on October 30, 2026 [2].
• The specific rule, found in a JSON file named “tengu_heron_brook,” instructs the model to build original games, games within a specific genre, and games based on a user’s own designs and assets, but forbids the recreation of specific existing games even if they are renamed [2].
• Addy Osmani confirmed the addition of these two sentences to the prompt on Opus 5.5 [1, 2].

Limits, Privacy and Academic Integrity

While the update aims to prevent IP infringement, there are several limitations and complexities noted in the reports:

• The prompt is designed to allow the creation of original games, games within a certain genre, and games built from a user’s own assets and designs [1, 2].
• Some reports on Anthropic’s GitHub suggest the new prompt may be getting in the way of certain game development use cases [2].
• There is a technical challenge in how the model distinguishes between a direct recreation of a game, such as Tetris, and a game that simply belongs to the same genre [2].
• The update may not stop all AI-assisted game copying, as users could potentially switch to other frontier models or cheaper open-weight models that do not have these specific restrictions [2].
• There is a risk that the restrictions could be too broad, potentially limiting transformative works that merge different game concepts [2].
• While decompilation through reverse engineering can be legal if expressive elements like art and sound are excluded, Anthropic’s guardrails are intended to prevent the tool from being used for direct cloning [2].