Riichi Mahjong Yaku
Ippatsu
Also known as: One Shot · 一発
A win within the first uninterrupted turn after declaring Riichi.
Yaku value
Closed hand
1 Han
Open hand
Closed only
Requirements
Win by Ron before your next draw or by Tsumo on that next draw after Riichi, with no intervening call or Kan by any player.
Common scoring mistake
Any Chi, Pon, or Kan interrupts Ippatsu. The Yaku cannot exist without Riichi or Double Riichi.
Values follow common modern Riichi rules. Local and tournament rules may differ, especially for double Yakuman.