Reverse-engineering games for converting them between systems is currently a hot topic, and it's getting messier by the day. According to multiple user claims, Anthropic's Claude Code and/or Opus 5.5 model are blocking attempts at innocuous reverse-engineering, including but not limited to those using the popular Reverse Engineer Anything (REA) tool. That issue may be linked to a text rule that's now in force, which allegedly instructs the model to avoid "[recreating] a specific existing game." According to Twitter user Chasm, the game-related textual rule is "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." There is no official or additional confirmation if this is the actual rule text, but it's plausible enough given the very clear refusals that devs have been encountering over the past week.

This situation is tricky to analyze due to the varying types of reports. First, the existence of a game-related rule is real, as Claude Code's GitHub is seeing an influx of issues complaining about refusals to do standard game work halfway through development, when replicating a game mechanic, and patching a tabletop-like game. It's possible that some of those reports have been made by users with nefarious purposes, but at least one is a bona fide developer with a real track record.