The competition standard used at international tournaments — 81 scoring patterns, the eight-point minimum for a winning hand, and the full set of eight flower tiles.
From the largest hands down to the smallest, every pattern in the international standard is recognised.
You cannot declare a win below eight points, which is what gives MCR its distinctive tension.
The four seasons and four noble plants are included, as in the official set.
Mahjong Competition Rules (MCR) is the international standard that came out of the Chinese official rules, and it is the ruleset of the Open European Mahjong Championship (OEMC), the World Mahjong Championship and the European Mahjong Association (EMA) MCR ranking. Clubs from the Netherlands and Germany to Italy, France, Denmark and Hungary play it every week.
This game is an independent implementation of the published rules, playable in any browser without an install. It is not affiliated with the EMA, the OEMC organisers or any federation.
MCR scores a hand by adding up every pattern it contains, from Big Four Winds and Thirteen Orphans at 88 points down to All Chows at 2 points and a single flower at 1. A winning hand must reach at least eight points from patterns alone; flower points do not count towards the minimum, which is why reaching eight is the first skill newcomers practise.
The game recognises all 81 patterns and applies the official non-identical and implied principles so the same shape is never scored twice. Every win shows the full breakdown, which is the quickest way to learn which combinations your hand was quietly building.
Chow, pung and kong claims work as in the official rules, and the eight flower tiles are set aside and replaced from the wall as they are drawn. On a self-drawn win every opponent pays the hand value plus eight; on a discard the discarder pays the hand value plus eight and the other two pay eight each.
Rounds, seat winds, prevalent winds and the dealer rotation follow the competition format, so a solo session against AI rehearses the same situations you will meet at a tournament table.
A free ten-lesson course teaches the patterns in families rather than as a list of 81, then walks you through reaching eight points on real hands. Learning mode in the game can show your waits while you play against three AI opponents of different styles.
For club practice, create a room and share one invite link: four players join from any browser, the seat is held across a dropped connection, and AI fills an empty chair. Riichi, Korean, Sichuan, Guangdong, American and Taiwanese tables run on the same site.
Mahjong Competition Rules — the standardised Chinese ruleset used officially at international tournaments such as the Open European Mahjong Championship and the EMA circuit.
Yes, it follows the public Mahjong Competition Rules with all 81 patterns and the eight-point minimum. It is an independent implementation and is not affiliated with the EMA or tournament organisers.
No. Flowers add one point each after you have reached the eight-point minimum from patterns, exactly as in the rulebook.
There is no riichi and no dora. Instead you add up 81 scoring patterns and must reach eight points to win. Eight flower tiles are also in play.
Yes. MCR supports four-player online rooms with friends, using the same official profile as solo play.