Finding online sites that play Mah-Jong can be difficult as the most popular ‘Mah-Jong’ sites are tile-matching ones, which bear no relationship to the real game. My searches have found some genuine ones which allow you to play against opponents:
The first two websites offer a variety of rules, whilst the last three are dedicated to American National Mah-Jongg League (NMJL) rules.
One has to distinguish between two forms of play. In one, you play against computer controlled opponents (or ‘bots’) and in the other you can actually play against real people. If you wish to play against a real person then the NMJL sites work very well and are easy to use. The game, however, is quite different to other forms so you would have a learning curve if you do not already know the rules. In addition the rules change annually, so you need a subscription to the League to get a copy of them each year – an ‘NMJL card’.
Four Winds Mah Jong
‘Four Winds Mah Jong‘ does not actually give you an online game on its website. Instead the site provides an application which players download and run on their computers. If you wish to play by British rules against bots it apparently gives a you a good game. However, you may find there are technical problems if you try to play against real people. A free trial is available to download.
The application allows players to customise many aspects of the rules, including imposing caps on the number of chows and whether or not to permit dirty/mixed hands or to require clean/single-suit hands.
To change the number of allowed chows, go to File > Preferences > Rules > Winning & Draw. Then select from the “Rule preset” drop-down list at the top-right of this box. You can see the restrictions on clean hands (“No mixed suits”) and the maximum number of chows both in this window, in the section titled “Restrictions on winning”.
If you select a specific Rule preset, e.g. “British Official”, then you cannot change the parameters. However, if instead you go to the bottom of the drop-down list and select “Customized”, the parameters become available to edit. And now you can cap the number of chows allowed and force players to play clean.
In addition, multi-player on a local network and across the Internet may be possible, but require some advanced knowledge of how to configure one’s Internet router and firewall. As every router is different, the game programmer does not give specific instructions, but the game’s Help file gives details of which network ports and protocols must be permitted for a multi-player game to work; see the FAQ section for those details.
Mah Jong Time
‘MahJong Time‘ does not provide a game with BMJA rules. However, it does play a number of other rules including American, Chinese Official and Hong Kong. You can host a game and also join an existing one. There are potential problems, however, as the site (at the time of writing) uses Adobe Flash or Adobe Air, so is limited to web browsers that can support Flash. More importantly, Flash itself will not be supported beyond 2020.
There is a free trial, but it only allows you to join an existing game. Payment involves a complex system of “coins” and “chips” which buy you entry into games. The free trial allows between one and four free games per day (1000 chips allocated per day, minimum entry fee per game is 250 chips).
National Mah Jongg League
The ‘National Mah-Jong League‘ site doesn’t offer a free trial. The subscription is an up-front payment of $50 (2020). In addition you must have an active subscription to the League itself, costing $8. For this you get a membership number (required for registration) and a printed copy of the current year’s list of rules and permitted hands. A large-print version costs $9.
The game appears to play solely in a web browser.
Real Mah Jongg
‘Real Mah Jongg‘ offers a fully-functional fourteen-day trial. It plays in any modern web browser which can support HTML 5, so isn’t restricted solely to a limited range of computers. You must have a copy of the NMJL card to know the valid hands. However, the game supports NMJL cards from more than one year (e.g in 2020 it allowed you to play by 2017, 2018, and 2019 rules).
‘My Jongg’ offers a fully-functional free tier, capped at 8 hands per day. Like Real Mah Jongg, it plays in any modern web browser which supports HTML 5. It’s support for previous years’ NMJL cards goes back several years (e.g in 2020 it allowed you to play by 2014 rules).
I have never used any of these websites myself to play Mah-Jong, so I am indebted to Alex Morris for providing me with this information. His knowledge comes from trying, unsuccessfully (despite his IT skills), to play BJMA rules online against real people then settling eventually for the NMJL game.