These rules are described in detail in Mahjong Competition Rules (The World Mahjong Organization, 2006), also known as 'The Green Book'. They were first used in an official tournament at the World Championship 2002 in Japan. The first major European tournament played by these rules was the 1st OEMC in Nijmegen, the Netherlands, during wich event EMA was founded.

Besides the MCR-Rulebook the 'Tournament Regulations' and the 'Referee Manual' are the official guidelines for MERS tournaments as from January 1st, 2009.

Riichi (modern Japanese mahjong) was introduced independently in several European countries, and consequently slight differences in the rules existed 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 resulted in the EMA Riichi Competition Rules as standard for Riichi tournaments.

The rules were revised in 2012.

Riichi rule book

	Riichi – Rules for Japanese Mahjong
	Riichi – Rules for Japanse Mahjong - French version
	Riichi – Rules for Japanese Mahjong - Nederlandse vertaling
	Rules – Rules for Japanese Mahjong - Polish version
	Rules – Rules for Japanese Mahjong - Spanish version

Riichi overview sheets

	Riichi – Overview sheet
	Riichi – Overview sheet - Dutch version
	Riichi – Overview sheet - Finnish version