Rule Sets
Tournaments in the Mahjong Europe Ranking System are currently played by one of two rule sets: MCR or RCR. The former is known as 'Chinese (Official)' mahjong, the latter as 'Japanese Modern' mahjong.
Mahjong Competition Rules (MCR)
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 international tournament (outside China) at the OEMC 2005 in Nijmegen, the Netherlands.
Besides the MCR-Rulebook the 'Tournament Regulations' and the 'Referee Manual' are the official guidelines for MERS tournaments as from January 1st, 2009.
Riichi Competition Rules (RCR)
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.
