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Mahjong Master
beginner Special Common Closed Only

Ippatsu

一発 | ippatsu

Win within one turn cycle after declaring riichi, before any player makes an open call.

By Kenji Tanaka · Updated

Overview

Ippatsu is a 1-han bonus yaku awarded for winning within one uninterrupted go-around immediately after declaring riichi, that is, on your very next draw or on any discard before then, with no calls in between. The window is narrow: if any player calls pon, chii, or kan after your riichi and before your win, the ippatsu chance is cancelled, even if you still win later. Because it stacks on top of riichi and is then multiplied in value by any ura dora, ippatsu is a frequent reason riichi hands suddenly become large. It rewards declaring riichi on a wide, live wait, since the faster you are likely to win, the more often ippatsu lands. There is nothing to play for actively once riichi is declared, but the possibility of ippatsu plus ura dora is a major part of why an aggressive, early riichi tends to pay off over the long run.

Han Value
1 han

Example Hand

1m 2m 3m 5m 6m 7m 3p 4p 5p 8s 8s 8s 2z 2z

Conditions

  • You must have declared riichi on your previous turn
  • You must win before your next discard after declaring riichi (within one turn cycle around the table)
  • No other player may make an open call (chi, pon, or kan) between your riichi declaration and your win — any call by any player cancels ippatsu
  • You can win by either self-draw (tsumo) or claiming another player’s discard (ron)

Strategy Tips

  • You cannot “aim” for ippatsu — it’s a bonus that happens or doesn’t based on luck and timing. The main strategy is simply declaring riichi whenever it makes sense, and sometimes you’ll pick up ippatsu as a bonus.
  • Ippatsu is one reason riichi declarations create tension at the table. Other players may hesitate to make calls even if they want to, knowing that a call would cancel your ippatsu bonus but also reveal tiles.
  • When another player declares riichi, be aware that making any open call (even one unrelated to their hand) will cancel their ippatsu chance. This can be a small defensive benefit of calling.