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

https://brookssimpressiveop-ed.wordcanopy.com/posts/why-is-the-cabinet-the-main-point-of-interaction-in-slot-machines

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