How many types of mahjong are there?

There are several types of mahjong, with the most prominent being Chinese Classical Mahjong, Japanese Riichi Mahjong, and American Mahjong. Each variant has its own set of rules, scoring systems, and tile configurations. Additionally, there are regional variations and house rules that can further diversify the game. Overall, while the core concept remains similar, the gameplay can differ significantly across these types.