R Mahjong is a complete implementation of the Japanese version of Mahjong, otherwise known as riichi mahjong.

For instructions on how to play, please follow this link
http://riichimahjong.net/rules/

Features:
*Strong mahjong AI. Stable Dan 6.8 - 7.0 (Tenho Stable Dan). This AI is stronger than 99.7% of mahjong players on tenhou.net
* Learning mahjong game mode with hints from the AI.
* Detailed mahjong game statistics.
*LAN play (via Wi-Fi). You can play with any combination of people and bots.

*The rules are basically identical to the standard Japanese rules (with open tanyao, red fives, atozuke ari, and double ron).
*Several interface languages supported (English and Japanese).
*Recording and playback of game (step-by-step and automatic modes). Review is possible from point of view of any player.
*Types of advertising switchable according personal preferences.
*Completely free.