In view of playing Nagashi Mangan starting from the coming session, here’s the clarification regarding this rule. This section has been added under the “Rules” Page.

Criteria

• The hand reaches ryuukyoku i.e. no one wins a hand until only the dead wall is left.
• All discards of the player are either terminal (1 or 9) or honour tiles.
• The player does not have any discards being called by other players.
• The player is allowed to declare riichi or ankan.
• The player does not need to be in tenpai.

Payment

• Similar to a mangan tsumo, oya will receive 4k from all other players, while non-oya will receive 4k from oya and 2k from the other players.
• However, the player does not receive any additional rewards from honbas or riichi deposits.
• Tenpai payments no longer occur.
• If the event of MULTIPLE players completing Nagashi Mangan, repeat the payments as stated above.

Renchan

• A player who completed Nagashi Mangan as oya does not renchan unless his hand is also in tenpai.
• If oya is in tenpai, he is allowed to renchan after paying 4k for Nagashi Mangan.

Chombo

• Chombo by any player will overwrite Nagashi Mangan, meaning only the chombo payments take place and not Nagashi Mangan.

Credit to Lance