Mentsu: Difference between revisions

'''Mentsu''' {{kana|面子}} are the tile groups used for the [[Japanese mahjong|game]].  The groups follow a similar pattern to the regular card game, gin rummy, where the focus is on groups of three tiles and sometimes four.  They are subdivided into three types: '''shuntsu''' (sequence), '''koutsu''' (three-of-a-kind), and '''kantsu''' (four-of-a-kind).  They are further categorized by their state being "open" or "closed".  Forming these groups is a central part of [[Tile efficiency|developing a mahjong hand]], because it is required for attaining [[tenpai]] and completing hands altogether.  Two main factors go towards the formation of these tile groups: suit and number (or type).

Mahjong features four types of tiles in terms of suits: the numbered suits and [[jihai|honors]].  Every tile group must be single-suited; and thus, a tile group cannot be of mixed suit.  It is [[Chombo|improper]] to possess such a mix when declaring a win, as the hand would not be complete.   Honor tiles take an even greater restriction, by which tile groups must be of particular tiles.  Different honor tiles cannot be mixed with suited tiles or other honor tiles.  Tiles among honor groups must be identical to each other.  To complete these any of these tile groups, players must either self-draw from the wall or may [[Naki|call on discarded tiles]], presuming that two out of three of a tile group are in possession.  While the tile groups are subdivided into three categories, they are further subdivided into the state of being open or closed.

Tile groups involving four-of-a-kind take on a different nature than the other tile groups.  '''Kantsu''' {{kana|槓子}} must be declared by [[kan]], to be useful.  Kan is a special [[Naki|tile call]] in the game. This call forms a meld from four identical tiles.  After the declaration of "kan", then a special set of rules are invoked.