Claude Code's game-cloning ban

Anthropic has officially confirmed restrictions in Claude Code that steer the model away from cloning specific existing games, particularly in Opus 5.5. The rule, internally labeled 'tengu_heron_brook,' was introduced around October 27 via a server-side flag, meaning it applies to all sessions without a client update and has no user-accessible off switch. The verbatim instruction reads: "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." The rule was first spotted by a social media user known as 'chasm' and independently confirmed by XDA in Claude Code binary version 2.1.314, released October 30. Claude Opus 5.5 carries separate, independent instructions restricting game recreations in its own system prompt bundle. Users have reported additional blocks on reverse-engineering, though Anthropic has not confirmed those. The change is characterized as primarily a liability shield for Anthropic rather than an effective brake on the wider AI game-porting and copying trend.