Artificial Intelligence

Anthropic's Claude Game Cloning Ban Won't Stop AI Copying Boom

Anthropic has updated its system prompts to prevent Claude models from recreating specific existing video games, though industry experts argue the move will do little to stop the broader boom of AI-assisted game porting and copying.

Radwan AbdulhadiEditor and technology writer

Published: November 3, 2026 · Updated: November 3, 2026 · 3 min read

Anthropic's Claude Game Cloning Ban Won't Stop AI Copying Boom — Image: Ars Technica

New Prompt Restrictions Target Game Recreations

Anthropic recently introduced a new system prompt designed to stop its Claude models from re-creating specific, existing video games. While that move could help shield Anthropic from some liability, it is unlikely to slow much of the massive wave of AI-assisted game porting and copying that has emerged in recent months.

An AI decompilation enthusiast going by the name "chasm" was among the first to note the prompt change late last week, stating that a new rule appeared to be added to the Claude Code prompt around October 27 in a JSON file under the name "tengu_heron_brook".

The rule explicitly instructs the model to build original games, genre games, and games from the user's own designs and assets, while forbidding the creation of specific existing games even if renamed or called original. XDA later independently verified that the new rule appears in version 2.1.314 of the Claude Code binary, which was released on October 30.

Anthropic Confirms Policy Against IP Infringement

Following the initial community reports, Anthropic software engineer Addy Osmani confirmed on social media that the company added two sentences to Claude Code's prompt on Opus 5.5 to steer the model away from recreating specific games belonging to others, citing that using Claude to infringe intellectual property violates usage policies.

Osmani added that the prompt was designed to preserve standard development workflows for original titles, genre games, and custom assets. However, a handful of issue reports on Anthropic's GitHub suggest the new prompt is occasionally interfering with legitimate game development use cases.

The Broader AI-Assisted Copying Boom

Anthropic's new prompt arrives as AI coding tools empower a deluge of game projects based on existing work. This trend encompasses thrown-together copies of game demos that leave indie developers afraid to show their early work publicly, as well as thousands of AI-driven decompilation and porting projects for retro titles.

While what used to be a painstaking human effort is now orders of magnitude more efficient, veteran coders frequently complain that vibe-coded ports fail to meet traditional quality bars. The community shift has even impacted long-standing preservation efforts, prompting platforms like decomp.dev to shut down after newcomers began racing to port games using automated tools without contributing to original community work.

Why Restrictions May Have Limited Impact

Although Anthropic's new restrictions represent an effort to counter the flood of AI-powered copying, analysts suggest the policy is unlikely to create a significant overall barrier. Eager game copiers can simply shift to alternative frontier models that lack such limitations, or transition to cheaper open-weight models that maintain comparable capabilities.

Nevertheless, the prompt provides immediate legal protection for Anthropic by helping insulate the company from copyright liability related to generated code and IP infringement. Yet, defining the precise boundary between an unacceptable clone and a legally transformative work remains a complex challenge that even human courts struggle to adjudicate.