Cards, wheels, and reels hold casino lore in plain sight. One or two zeroes on...

https://varimail.com/articles/why-reels-became-the-default-way-to-show-slot-outcomes/

Cards, wheels, and reels hold casino lore in plain sight. One or two zeroes on a wheel mark a rule. Old cards show wear from play. In 1895, makers built slot gear by hand