Mahjong Book: Learn Riichi

Mahjong Book is a study-and-play companion for Japanese riichi mahjong.

Learn tiles, winning shapes, waits, yaku, dora, fu and scoring through real-tile lessons and quizzes. Spaced repetition brings a topic back when it is time to review.

In Scoring Training, every winning hand in an AI match becomes a live scoring problem: answer the fu and points, then see the worked explanation.

Play 4-player or 3-player mahjong offline against beginner, intermediate or advanced AI. You can also play online worldwide or create a private room with any 4-digit code to meet friends. Online chat uses preset phrases only; the app has no free-text chat.

4-player rules include a 25,000-point start, three red fives, open tanyao, atozuke, abortive draws, nagashi mangan, double ron, bankruptcy and West extension. 3-player rules include a 35,000-point start, North extraction as dora, tsumo loss, no chi, nine terminals, four-kans abort and double ron.

One-time purchase. No ads, no in-app purchases, and no gambling. Switch the in-app language between English and Japanese at any time in Settings.

--- 日本語 ---
「麻雀の書」は、リーチ麻雀を学び、点数を計算し、対局できるアプリです。実際の牌を使った講座・クイズ、AIとの符計算修行、四人打ち・三人打ちのAI対局、4桁コードを使うオンライン対戦に対応しています。