Rule34dle is a web-based game designed to test and challenge players' knowledge of character popularity across various internet cultures and media franchises. Players are presented with two characters and must guess which one has a higher number of associated posts or mentions. The game features different modes like Normal, Ultimate Battle, and Quick Battle, with mechanics for building streaks, competing on a global leaderboard, and customizing difficulty. It emphasizes instant play with no signup or download required, offering daily missions and a focus on skill-based competition without ads or tracking in Stealth Mode.