Beginner's Lesson 12
Single-suit Yaku
In this lesson, we will cover the most common yaku in riichi mahjong, riichi. But first, we have to discuss another unique aspect of riichi mahjong, dora.
Dora are tiles that are worth 1 han each, just by having them in your hand. However, just because dora are worth han does not mean that they are a yaku. You must have a yaku to win a hand and benefit from the bonus han that dora provide.
But how do you know what tiles are dora? At the beginning of each hand, 1 tile in the dead wall is flipped face-up; this is the dora indicator tile. The dora will be the tile “after” the dora indicator tile. For example, if the dora indicator is 4pin, then the dora is 5pin. If the dora indicator is a 9, then the dora is the 1 in that suit.
If the dora indicator is a wind tile, then the dora is the next wind tile in the sequence:
East > South > West > North > East
If the dora indicator is a dragon tile, then the dora is the next dragon tile in the sequence:
Chun > Haku > Hatsu > Chun
For the wind tiles, it goes in the same order as the seat winds around the table. For the dragon tiles, it goes in alphabetical order.
Dora tiles are very valuable due to how easily they can increase the value of a hand. Consider the effort it takes to build a hand around certain yaku like sanshoku or chanta. Just having one or two dora could make a hand worth as much or more than having these restrictive yaku.
However, you still need a yaku to complete a winning hand. You may end up in a situation where you have multiple dora but no yaku. That is where the yaku, riichi, comes in.
Riichi is a yaku that can be given to any hand that is in tenpai and is also closed (meaning that you have not called another player’s tile, which will be covered in the next lesson). When you are in tenpai during your turn, you can declare, “riichi”, before you discard a tile. Then, you discard the tile sideways and put a 1000-point stick on the table (if someone declares ron on that discard, then you do not have to give up the 1000 points; the order is important!). At this point, your hand gains the yaku, riichi, which is worth 1 han.
However, once you declare riichi, you must discard any tile you draw that does not complete your hand (there is one exception that will be covered in the next lesson). You cannot change your hand anymore, and just have to wait and see if your winning tile comes out. The 1000 points you bet also go to the next player who wins a hand, and that might not be you.
Riichi does have these disadvantages, but the advantages more than make up for them. There is a special yaku associated with riichi called, “ippatsu”. Often translated as “one shot”, it is a yaku that you can gain if you are able to win within 1 turn after declaring riichi. That means you can get ippatsu from any one of your opponents’ next discards and your next draw. Ippatsu is worth 1 han.
Additionally, winning a hand with the yaku riichi allows you to reveal another dora indicator. The dora indicated by this new indicator is called, “ura dora”. That’s because the new indicator you reveal is the tile beneath the current dora indicator. With a little luck, you can increase the value of your hand with little effort. Considering these factors, it is usually a good idea to declare riichi once you reach tenpai with a closed hand.
Lastly, we will cover one more yaku that is often combined with riichi: menzen tsumo. Usually shortened to just, “tsumo”, menzen tsumo is a yaku you gain if you win by tsumo with a closed hand. Naturally, it is easy to combine with riichi, which also has the closed hand condition. However, you can claim menzen tsumo even without riichi or any other yaku, so long as you draw your winning tile while your hand is closed (again, this means that you have not called another player’s tile). Menzen tsumo is worth 1 han.
Here are two videos by Light Grunty explaining how to set up the wall and the dora indicator tile, and about the yaku riichi and menzen tsumo:
Setting Up
Yaku, Riichi, and Menzen Tsumo
With just riichi and dora, hands with no other yaku can become very expensive. They are defining aspects of riichi mahjong, so please take care to learn them well.
In the next lesson, we will cover calling other players’ tiles and open hands.