Yakuhai
Also called: 役牌, value tile
Riichi: a pung of dragons, seat wind, or round wind. Each is worth 1 han.
Yakuhai means 'yaku tile' — the tiles that automatically score han when held as a pung. There are five potential yakuhai per round: the three dragons (always count) plus your seat wind and the prevailing round wind. Each yakuhai pung adds 1 han. Stacking is possible: a pung of East when East is also the round wind is worth 2 han.
- Dragon
The three special honor tiles — White, Green, and Red — that always score.
- Wind
The four directional honor tiles — East, South, West, North.
- Seat wind
The wind tile matching your seat — East/South/West/North relative to the dealer.
- Round wind
The wind that's active for the current round — usually East, then South, etc.
- Yaku
Japanese-only term for a named scoring pattern. Every winning Riichi hand needs at least one yaku.