hand structure riichi

Chiitoitsu

七対子

(チートイツ)

Definition

Seven pairs - a 2-han yaku where your hand consists of seven different pairs. Always worth exactly 25 fu. Must be closed.

対子

Two identical tiles. Also called atama or jantou. Every standard winning hand requires exactly one pair.

役

Scoring patterns or hands. You must have at least one yaku to win (except with riichi). Each yaku is worth a certain number of han.