A JavaScript/TypeScript library for calculating riichi mahjong hand scores.
- Automatically calculates fu (hand points), han (hand value), and final basic points.
- Handles standard and non-standard hands, open and closed melds, seat winds, dora indicators, and more.
- Returns details such as fu breakdown, yaku list, and seat payments.
npm install riichi-scoreimport { calculate, createGameState } from "riichi-score";
// 1. Create or structure your hand data
const handData = {
closedTiles: ["1m", "2m", "3m", "9p", "9p", "9p", "4z", "4z", "4z", "7z"],
openMelds: [
{
type: "set",
tiles: ["6z", "6z", "6z"],
from: "north",
},
],
winningTile: {
tile: "7z",
from: "north", // ron
// for tsumo, you can set isTsumo: true and omit `from`.
},
gameState: createGameState({
roundWind: "east",
seatWind: "east",
doraIndicators: ["1m"],
uradoraIndicators: ["6z"],
}),
};
// 2. Calculate the hand result
const result = calculate(handData);
/*
{
"valid": true,
"errors": [],
"handInterpretations": [
{
"isStandardHand": true,
"waitType": "tanki",
"pair": {
"tiles": [
"7z",
"7z"
],
"isFinalWait": true
},
"groups": [
{
"tiles": [
"1m",
"2m",
"3m"
],
"type": "run",
"open": false,
"isFinalWait": false
},
{
"tiles": [
"9p",
"9p",
"9p"
],
"type": "set",
"open": false,
"isFinalWait": false
},
{
"tiles": [
"4z",
"4z",
"4z"
],
"type": "set",
"open": false,
"isFinalWait": false
},
{
"tiles": [
"6z",
"6z",
"6z"
],
"type": "set",
"open": true,
"from": "north",
"isFinalWait": false
}
],
"winningTile": {
"tile": "7z",
"from": "north"
},
"gameState": {
"roundWind": "east",
"seatWind": "east",
"doraIndicators": [
"1m"
],
"uradoraIndicators": [
"6z"
],
"isRiichi": false,
"honbaCount": 0
},
"basicPoints": 2000,
"seatPayments": [
{
"seat": "north",
"value": 12000
}
],
"totalWinnings": 12000,
"isTsumo": false,
"yaku": [
{
"name": "hatsu",
"han": 1
}
],
"fuList": [
{
"reason": "base",
"value": 20
},
{
"reason": "yakuhai pair",
"value": 2
},
{
"reason": "tanki wait",
"value": 2
},
{
"reason": "closed triplet of terminals/honors",
"value": 8
},
{
"reason": "closed triplet of terminals/honors",
"value": 8
},
{
"reason": "open triplet of terminals/honors",
"value": 4
}
],
"rawFu": 44,
"fu": 50,
"han": 4,
"dora": 1,
"akadora": 0,
"uradora": 2
}
]
}
*/