Optional yaku

Optional yaku are additional yaku, which may be appended to the standard list according to specific house rules.

Optional yaku

[[Daichisei]] 「大七星」 Closed only Yakuman, or double yakuman	The seven pair variant to tsuuiisou. This may count as an independent yakuman pattern. Otherwise, it may be counted as tsuuiisou.
	Agari:

[[Daisharin (pinzu) Daichikurin (souzu) Daisuurin (manzu)]] 「大車輪、大竹林、大数隣」 Closed only Yakuman	Any hand that follows this pattern: 22334455667788. The pattern for each suit takes on a different name.
	Agari:

Open riichi 「オープン立直」 Closed only 2 han	Riichi called where the hand or the tile waits are revealed.

Paarenchan 「八連荘」 May be open, Dealer only Yakuman

If the dealer wins a hand with eight honba on the table, the hand is scored for yakuman regardless of its usual value, and then the dealership rotates. Usually, paarenchan is not a true yaku and the dealer must still have another yaku to declare a win, but this is not always the case. The exact counting of wins may also vary; some rules may award the yakuman on the eighth win, rather than the ninth, and some rules may require the dealer to actually accumulate that many wins, not just any honba.

[[Renhou]] 「人和」 Closed only Varies as yakuman, mangan, 5 han, etc.	A non-dealer player wins on a discard at the first round.

[[Sanrenkou Isshoku sanjun]] 「三連刻、一色三順」 May be open 2 han	Three consecutive triplets.
	Agari: or

Shiisanpuutaa 「十三不塔」 Closed only Yakuman	A player is dealt a hand, by which, no two tiles can reasonably form a tile group with a tile draw. For completion, one tile may be paired.
	Agari:

Shiisuupuutaa 「十四不塔」 Closed only Yakuman	A player is dealt a hand, by which, no two tiles can reasonably form a tile group with a tile draw. For completion, no tiles are paired.
	Agari:

[[Suurenkou Isshoku yonjun]] 「四連刻、 一色四順」 May be open Yakuman	Four consecutive triplets.
	Agari: