Two very different games
American players build toward specific card hands with jokers and the Charleston; riichi players build flexible four-set hands that must contain a yaku, with no jokers and no flowers.
Information and defense
In riichi, discards sit in orderly rows, furiten makes some tiles provably safe, and a riichi declaration announces danger. In American play, exposures reveal hands and defense means avoiding tiles that complete visible card hands.
Scoring
American scoring is simple — each hand's value is printed — while riichi scoring combines han and fu, with limits from mangan to yakuman.
Which suits you?
Players who enjoy pattern-matching and social games often love American Mah Jongg; those who enjoy probability, defense and competitive ladders are often drawn to riichi. Learning one makes it easier to appreciate the other.
