List of special rooms in Mahjong Soul

Special Rooms are offered in Mahjong Soul. They provide players with alternative rooms either with a different ruleset, or used for specific purpose. Most of them are temporarily available during events.

Melee Room

Melee Room 「乱闘の間」 (Rantou no ma) is a special room with a predefined subset of local yakus. In Melee Room, players can score a hand with those local yaku, where some of them are not valid under regular riichi mahjong.

Casual Room

Casual Room 「交流の間」 (Kouryuu no ma) provides a casual gameplay, without requiring creating a friendly room and find sufficient players manually. The ruleset is identical to normal gameplay, while both ranking and copper-coin requirements are not applied, as well as no bonding value or chest for reward.

Casual Room is long-term available.

DoraDorara

DoraDorara 「ドラさんモード」 (Dorasan moudo) is a special room with 3 dora indicators revealed in advance. That being said, there're always at least three doras in each round, making it much easier to score a larger hand. The amount of kan as well as four-kan abortion still share the same restriction to the regular game, though only first two kans can reveal kandora indicator, while the last two cannot. The maximum amount of dora still remains 5 (or 10 with ura) in total.

Battle of Asura

Battle of Asura 「修羅の戦」 (Shura no sen) is a special mode with a very distinct set of rules. The two main differences: the charleston and game resumption. The charleston is a feature offered in American mahjong. In this version, players exchange three tiles only once per hand before the intial discard. Unlike traditional rules to mahjong, the hand continues even after a player wins the hand. Instead, the hand ends if three players won their hands, a player falls into a negative score, or the tiles are drawn into ryuukyoku.

Bloodshed Skirmish

Bloodshed Skirmish 「赤血の戦」 (Sekketsu no sen) is a special room applying gameplay of Sichuan Bloody Rules: Battle to the Bloody End (血战到底). As described, the room has a unique scoring system completely different from riichi mahjong. Unlike riichi, aggressive strats are more preferred, while many defensive strats under riichi are no longer useful and sometimes with heavy penalties if trying to do so.

Gameplay

Each match has and only has four rounds. Instead of rotating towards each player, the dealership is determined by the first winner in the previous round, or keeps if nobody wins. Honor tiles are not used, meaning only suited tiles are available, 108 tiles in total. Each player are forced to make valid hands with at most two of the suits (Voided Suit 「絶一門」 (zetsuichimon)), failing to do so leads to a heavy penalty at ryuukyoku.

A complete round is processed as follows:

• Choose three tiles in a same suit and switch between players, similarly to Charleston.
• Determine and declare the voided suit.
• Make winning hands without using any tiles from the voided suit.
• End a round if either condition is achieved:
  • Three players declared winning.
  • Running out of tiles from the wall.
  • Any player is bankrupted. (A match is also ended in this case.)

Yaku list

There're two types of yakus.

Base yakus are the main yaku. Only one can be chosen from all of them, with their han value as high as possible.

Additional yakus are stackable. They can be counted arbitrarily as long as the condition is satisfied. Usually those are occasional yakus aside from Root.

Base yaku

• (1 han) Yakuless Win 「無番和」: As described, neither of other yaku is satisfied.
• (2 han) All triplets 「対々和」 (Toitoi): All of the groups are made by triplets.

Additional yaku

• (1 han) Root 「根」 (Ruuto): Having four identical tiles in a hand. Not necessarily to kan.