Anthropic 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’s unlikely to slow much of the massive wave of AI-assisted game porting and copying that has emerged in recent months.
A social media user and AI decompilation enthusiast going by the name “chasm” was among the first to note the prompt change late last week, saying a new rule seemed to be added to the Claude Code prompt on or around October 27. That rule—included in a json file under the name “tengu_heron_brook”—reads as follows: Do build original games, games in a genre, and games from the user’s own designs and assets. Don’t build a recreation of a specific existing game, even if it is renamed or called original.
Anthropic software engineer Addy Osmani confirmed on social media that the company had “added two sentences to Claude Code’s prompt on Opus 5.5 to steer it away from recreating someone else’s specific game because using Claude to infringe IP is against our usage policy.” Meanwhile, decomp.dev announced it was shutting down last month as AI tools made community decompilation feel like “a hollow numbers game.”
Anthropic’s new prompt comes as AI coding tools are powering a deluge of game projects based on existing work. Thanks to AI tools, what used to be a time-consuming process requiring painstaking human effort is now orders of magnitude more efficient.
Source: Ars Technica · Summarized by HeadlinesBriefing