Rhystic Study is a blue enchantment from Magic: The Gathering, first printed in the Prophecy set, that lets its controller draw a card whenever an opponent casts a spell unless that opponent pays one extra mana. That repeated choice made the question 'Do you pay the one?' a running joke in Commander games, where the card is especially common and the tax comes up constantly. Streamers and players began repeating the line at tables and in gameplay videos, and it stuck because it captures the card's annoying, unavoidable pressure in just a few words.