Anthropic updates AI model to block game cloning

Anthropic has updated its Claude Opus 5.5 model to prevent it from recreating existing games. The update aims to stop AI-generated copies of popular games from appearing on platforms like Steam and eShop.

New instructions added to AI prompt

The update adds two sentences to the Claude Code prompt, instructing the model to "build original games, games in a specific genre, and games based on the user's own designs and resources. Do not recreate an existing game, even if it is renamed or presented as original." This change was first noticed by user @Chasm on X and confirmed by Addy Osmani, a member of Anthropic's technical team.

Examples of AI-generated game clones

The update comes after reports that fans have used Claude to recreate popular games such as Fallout and GTA V under different names. For example, a user named Chris First reportedly asked Claude Opus 5.5 and a team of AI agents to "recreate Fallout, in New York," resulting in a playable browser-based game with 117 locations and 112 characters.

Legal challenges for Anthropic

Anthropic has also faced legal challenges related to its AI models, including a $1.5 billion agreement with authors whose pirated books were used to train Claude, and ongoing copyright disputes with the heirs of Elvis Presley. The company has not specified whether other models besides Opus 5.5 are affected by the new instructions.

AI model refuses unrelated requests

Developers have reported that Claude Code is also refusing requests unrelated to game copying, such as analyzing Windows crash reports or cleaning pre-installed applications on Samsung televisions. This is because such tasks may involve reverse engineering, a technique also used by clone enthusiasts to decompile game executables and recreate them with AI agents.

Uncertainty over user project ownership

Anthropic has not explained how Claude determines whether a project belongs to the user. The model will accept coding requests for original platform or shooting games but must refuse to reproduce levels and characters from well-known titles. Addy Osmani stated that the company will continue to iterate on the policy to find the right balance and encourages developers who are blocked to contact him directly.