Claude’s new rules against game cloning won’t stop the AI copying boom

Last week, 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: