Mahjong Lai Zi, also known as "Laizi". In four-player mahjong, after the dealer grabbed the 14th card, the first card flipped plus one is laizi. A laiji can be used as any tile or a wild card, or it can be used to win with the laiji's own suits. When there are two royals, you can't play a small hand.

In Cantonese mahjong, a laizi is a special tile, and two laizis can be combined to form a set of tiles, or another set of tiles if used as a single tile. Lai Zi is an important combination of tiles, with which you can win or lose.

In general, the meaning of Mahjong Raiko may vary from region to region and from rule to rule, but they all represent a special kind of tile that plays an important role in the game.