Riichi (modern Japanese mahjong) has been introduced independently in several European countries, and consequently slight differences in the rules exist across the continent. With the scheduling of the first European Riichi Championship in 2008, the need arose to standardize the riichi rules in the context of the European Mahjong Association.
This booklet describes the standard riichi rules of the European Mahjong Association. Thanks go to Sjef Strik, Jenn Barr and Benjamin Boas for great help in shedding light on rule differences and practices and for invaluable advice.
Some rules that have rooted in Europe are different in Japan, notably these three cases: 1. All Simples can only be claimed for a concealed hand. 2. When five counters are on the table, a two yaku minimum is invoked. 3. It is permissible to chow a tile and discard an identical tile from the hand.
Tina ChristensenEuropean Mahjong AssociationMay 14, 2008http://mahjong-europe.org/The rules have been revised in order to avoid ambiguities and scoring examples have been added for clarity. The uma has been increased, double yakuman has been omitted except for Big Four Winds and rules on etiquette and tournament play have been added.
Tina ChristensenEuropean Mahjong AssociationJanuary 8, 2012http://mahjong-europe.org/