Rules

Mandatory

Atozuke(後付け)

Allows a hand to win despite having no guaranteed yaku while in tenpai, as long as the winning tile generates a yaku.

Furiten(振聴)

A rule that does not allow a player to win by a ron on a tile that he has already discarded. In this case, the player still has a chance to win on the tie drawn directly from the live wall.

Ryanhan shibari(二飜縛り)

A minimum limit of 2-han is applied to winning hands. Usually, this is applied when the honba count reaches 5.

This rule is also subject to change depending on the general rules set by the tournament.More often than not, two manifestations of the foriten can be found:

1. The classic manifestation of the Furiten rule prevents a player from winning a RON on any of the waiting tiles if at least one has already been discarded by the player. You have to be very careful when discarding tiles.
2. The most frequent manifestation of the rule allows to win on those waiting tiles, which were not discarded by the player.

Optional

Agariyame(和了り止め)

Allow the dealer to end the hanchan prematurely, while in possession of the lead in the round South 4 or in the West round after one hand has been played.

• Lead – Allow the dealer to end the hanchan prematurely, with the last dealer is in the lead.
• End – The dealer may end the game after one hand in the final round, regardless of point standing.
• Nashi – The game must continue until the seat winds rotate again.

Aotenjou(青天井)

A rarely used rule, which eliminates the score cappings mangan, haneman, etc., and scores all hands as directly with the scoring formula.

Ari ari(アリアリ)

Ruleset which allows kuitan and atozuke. Most common basic set of rules in Japan. Opposite of Nashi nashi.

Atamahane(頭跳ね)

A rule that allows only one Ron at a time; the closest to the discarder in turn order takes priority. Opposite of Daburon.

Basengo(場千五)

A rule where each honba counter is worth of 1500 points instead of the regular 300 points.

Daburon(ダブロン)

A rule that allows two people to simultaneously win from the same discarded tile.

Furiten riichi

Allow players to declare riichi while they are furiten due to their own earlier discards.

Kiriage Mangan(切り上げ満貫)

A rule where 3 Han 60 Fu and 4 Han 30 Fu are rounded up to Mangan.

Kuikae(喰い替え)

A rule that allows you to call a tile, then discard another tile that could have completed the tile group. For example, calling a 1 when you have 234 and then discard a 4.

Kuitan(喰い断)

A rule that allows tanyao to be open.

Nashi Nashi(ナシナシ)

Ruleset which disallows kuitan and atozuke. Opposite of Ari ari.

Pao(包)

If a player claims a discard to make an open quad and then completes their hand with a tile drawn from the dead wall, the player who discarded the tile is responsible for paying the entire amount for the hand.

Wareme(割れ目)

A rule that doubles any payment involving the player whose wall was broken at the start of the hand.

Chombo

Local yaku