Tools
Each tool deals a winning hand from one of the rulesets in the tree and scores it.
The rulebooks are the sources; each tool names its own. The code that deals and scores was written by an AI model from that rulebook, so where a score disagrees with it, the rulebook is right.
Hand Score Simulator
Japanese Riichi Mahjong
Deals a winning riichi hand and scores it under the EMA Riichi Rules 2025: its yaku, fu, dora and payment.
Hong Kong Hand Scorer
Modern Hong Kong Mahjong
Deals a winning Hong Kong hand and counts its faan under the Hong Kong Mahjong Association’s competition rules — three faan to win, ten as the ceiling, and the discarder paying the lot.
Hong Kong Old Style Scorer
Hong Kong Old Style Mahjong
The older house game that the competition rules came from. Flowers score fan, payment uses the Half-Spicy table, and everyone pays when a player wins off a discard.
Taiwanese Hand Scorer
Taiwanese 16-Tile Mahjong
A 16-tile hand (five sets and a pair) scored in tai, with extra points for and against the dealer, a streak bonus, and no scoring cap.
Vietnamese Classical Scorer
Vietnamese Mahjong, the 160-tile set
The pre-1975 set: 160 tiles with eight khung in the wall. Hands score by name, not by adding up points, six phán make a mủn, and a hand with no jokers scores more.
Vietnamese Modern Scorer
Vietnamese Mahjong, the 176-tile set
The same rules on the modern set: 176 tiles and three sets of khung. With so many jokers, a hand without one is rare and scores the most.