Anthropic tweaks Claude Code prompt to curb game cloning
The two added sentences allow original and genre games, while users report refusals on reverse engineering and security tasks.
Anthropic added two sentences to the Claude Code prompt for Claude Opus 5.5 to steer the tool away from recreating someone else's specific game, according to technical staff member Addy Osmani. The change, first reported by Tom's Hardware, follows a wave of user reports that legitimate development work is also being refused.
The new rule states that original games, games built within an established genre and games designed by the user are allowed, but that recreating an existing specific game under a new name must not be done. Osmani said on X on October 30 that the two sentences were added to the Opus 5.5 prompt for that purpose.
According to the Tom's Hardware report, Claude Opus 5.5 users have complained on GitHub and social media about refusal messages during game development and reverse engineering tasks. Reported examples include developers being blocked from building anti-cheat systems for their own games, checking their software for security vulnerabilities, and modifying a tabletop-style program.
Users also reported being unable to use a tool called Reverse Engineer Anything, to analyze Windows crash dumps, or to remove unwanted software from a Samsung TV.
Osmani said Anthropic will keep refining the rules and asked users to report legitimate projects that were wrongly blocked. On October 27, X user Chasm was the first to spot the newly added game development rules in Claude Code.
Earlier policy changes
On October 6, Anthropic expanded its Cyber Verification Program, dividing access to advanced cybersecurity features into three tiers and easing some limits for verified security experts and organizations. On October 16, indie developer Alliance Arts cancelled the October 19 demo release of its game Drunken Goddess Reflux, citing the risk of the demo being used for AI-based game imitation.
Quick answers
What does the new Claude Code rule allow?
Original games, games in an existing genre and user-designed games are allowed, but recreating an existing specific game under a new name is not.
Which model does the rule apply to?
The two added sentences were written into the Claude Code prompt for Claude Opus 5.5, according to Addy Osmani.
What should users do if a legitimate project is blocked?
Osmani asked users to report legitimate projects that were wrongly blocked, and said Anthropic will keep refining the rules.