Automatic mahjong machines use specially designed mahjong tiles with small magnets embedded inside. They typically prepare two sets: one for use on the table and the other for shuffling inside the machine, saving time while waiting for shuffling. The shuffling area inside the machine has strong magnetism, but it's a certain distance from the playing table, where the magnetism is weak enough not to affect play.
The core internal structure of an automatic mahjong machine includes a large central shuffling disc and surrounding magnetic rollers. The magnets on the rollers are oriented to create an opposite attraction with the magnets inside the mahjong tiles. Tiles face up are directly attracted, while face down tiles are pushed away due to repulsion. Magnets are also located at specific points on the bottom of the large disc; tiles pushed away are flipped over again at these points due to the repulsion principle.
