What is Dora in Riichi Mahjong? Bonus Tiles Explained
Dora are not a yaku — but every dora in your winning hand adds 1 han to the final score. Here is how the system actually works.
What is dora?
Dora (ドラ) are bonus tiles that add 1 han to your final score for each one in your winning hand. They are not a yaku, so they cannot let you win by themselves — you still need a real yaku — but they multiply the value of an already winning hand. Riichi alone is 1 han; riichi with three dora is 4 han.
How do you know which tiles are dora?
At the start of the hand the dealer flips one tile from the dead wall, called the dora indicator. The actual dora is the next tile in sequence. If the indicator is 4m, then 5m is the dora; if it is 9m, the dora wraps around to 1m. For winds the cycle is East → South → West → North → East; for dragons it is White → Green → Red → White.
What are aka dora (red fives)?
Aka dora (赤ドラ, literally red dora) are special red-colored 5m, 5p and 5s tiles that count as 1 han each. They stack with regular dora and are independent of the dora indicator system. Most modern rulesets include one red 5 per number suit.
What is ura dora?
Ura dora (裏ドラ, literally underneath dora) only count when you win after declaring riichi. After such a win, the tile underneath each dora indicator is flipped to reveal an ura dora indicator, and the same offset rule determines the ura dora itself. Riichi plus ura dora is one of the most common paths to a big hand.
What about kan dora?
Whenever any player declares a kan, a new dora indicator (kan dora) is flipped — adding to the dora pool for the rest of the hand. If the winner also declared riichi, the tile under each kan dora indicator is also revealed as a kan ura dora indicator. Regular dora, ura dora, kan dora and kan ura dora all stack.