Anthropic updated a game development rule in Claude Code version 2.1.317 to allow users to reference existing games when describing desired gameplay mechanics, according to Claude Code team member Addy Osmani. The previous restriction, added to Opus 5.5's prompts, blocked Claude from replicating specific existing games to prevent intellectual property infringement but also caused refusals when users simply borrowed a game title as shorthand for a gameplay concept. Under the revised policy, when a user mentions an existing game to describe requirements, Claude will now produce an original game of the same genre rather than refusing outright. If a user explicitly requests copying the original work, Claude will propose creating a similar game instead.