As the title of this section says, these are special rules and features. They may not apply to every video mahjong game in MAME. Some may, some might not.

Why won't the game let me go out? I have a complete hand, but when I try to declare mahjong, the game does not response but forces me to do something else. There are two main reasons for why this may occur:
  • You have no Yaku
  • You have a Furiten

Read below for details on each.

You cannot go out with just any hand. For you to go out, your hand must contain at least 1 Yaku. If it does not fulfill this requirement, then the game will not allow you to win the round, even if you have a complete hand of 4 sets and a pair.

You can receive Yakus from having certain tiles or sets within your hand. Or you can receive Yakus in certain situations depending on how exactly you went out to win the round. Here's a list of just a few of the ways that you can obtain a Yaku:
  • Having a Pon or Kong of any Dragon in your hand.
  • Having a Pon or Kong of your wind or the prevailing win in your hand.
  • Going out with a hand containing only Simples, meaning having no Terminals (1s or 9s), Winds, or Dragons.
  • Going out with a hand containing 3 Chi of each suit with the same number sequence.
  • Going out with a hand containing a 1-9 sequence of any suit.
  • Going out with a hand containing 4 Pons and a Pair.
  • Going out with a hand containing 3 Kongs.
  • Going out with a Reach.
  • Going out with a Tsumo and with a concealed hand.

Meeting any one of these can earn you a Yaku. Meeting any two of these can earn you two Yaku and so on. Basically you receive Yakus for every possible Yaku situation or tile combination that you fulfill with your hand. Some conditions can earn you a single Yaku like the ones above, while others can earn you 2 or more.

Each Yaku is worth one Fan. Fans are useful scoring-wise as each Fan can double your score. Which means that the more you have, the more your score will be when you win.

There are tons more conditions that can earn you Yakus not listed here. For a full listing head over to the Yaku section.

This rule should apply to all mahjong games.

Even though you have Yakus in your hand, you may still be unable to go out if you have a Furiten. Furitens are only of concern when going out by declaring Ron. Going out by Tsumo does not apply. 

A Furiten, or sacred discard, is a tile that you cannot declare Ron with because you have previously discarded that tile before. It is within your discard pile. Let's say for example that you need a 2-dot tile to go out. The opponent discards a 2-dot tile. If you have a 2-dot tile within your discard pile, you would not be able to declare Ron because the 2-dot tile is a Furiten.

To make matters even worse is that if you have more possible tiles to choose from to go out and one of those tiles happens to be a Furiten, then you cannot declare Ron with any of those tiles. So if you need either a 2-dot tile or East Wind tile to go out and the 2-dot tile is a Furiten, since it is a tile that you have discarded before, then you cannot declare Ron with neither tile. Of course, you can still declare Tsumo with either one if you happen to draw one of those tiles yourself.

This rule should apply to all mahjong games.

Often times, you are penalized whenever you pass up a winning tile after declaring Reach. Many games will not allow you to go out on a winning tile if you have already passed up a winning tile before hand.

After declaring Reach, if you pass up a winning tile drawn by you, then that tile becomes a Furiten since it is now part of your discard pile. Because it is a Furiten, as mention before, you can no longer go out with that tile or any other tile possibilities that you have by Ron. However, Tsumo can still be made.

After declaring Reach, if you pass up a winning tile discarded by the opponent, then you are not allowed to go out by Ron on any other winning tile that is discarded again by the opponent. Tsumo may or may not be allowed as well.

This rule should apply to most mahjong games.


If you are the dealer and remain dealer for 5 consecutive rounds in a match, 2 Yakus may now be required to go out instead of the typical 1 Yaku. Staying dealer for 5 straight rounds usually means that you have been winning or have been close to winning 5 straight times. In order to cool you off and stop you from making cheap 1 Yaku hands, 2 Yakus are now required for your hand in order to go out.

This rule may or may not apply to most mahjong games.


In normal four player mahjong, prevailing wind starts off as east wind. After dealership has made its way around the entire table, and the dealer at the start is dealer again, the prevailing wind changes to south wind. After dealership makes its way around the table again, the prevailing wind changes to west, north, and repeats. Another way to think of it is that prevailing wind changes after every 4 switches in dealer.

Similarly after 4 switches in dealership, the prevailing wind for the round is changed in two player mahjong. So in essences, dealership needs to make its way around the table twice rather than once.

This rule may or may not apply to most mahjong games.

Perhaps the easiest hand to get in mahjong is a Pinfu, or an all Chi hand. As a result, rules have been applied to this hand not much so as to make a Pinfu tougher to obtain, but really to make the hand as worthless as can get. Almost anything that can add value to the hand like a scoring pair or going out by one-chance are all excluded when making this hand. Hell, you don't even receive the measly 2 points for Tsumo. A Pinfu isn't called a No-Points hand for nothing :)

To add further difficulty of the hand is the Tsumo Pinfu rule. This rule, if applied, only allows a Pinfu to be made by Tsumo. You do not receive the Yaku for Pinfu if you go out by Ron.

If the game does not apply the Tsumo Pinfu rule, then you can receive the Yaku for Pinfu if you go out by Tsumo or Ron.

Note also that some games actually lets you adjust whether or not you want to apply the Tsumo Pinfu rule in the game's dip switch.

Kuitan is a general rule in mahjong that deals with a Tanyao hand. A Tanyao hand, of course, is a hand consisting of only Simples. The rule states that you can receive a Yaku for Tanyao if your hand is revealed or concealed. That means that you can still receive the Yaku even if you have revealed sets in your hand.

Most games apply the Kuitan rule, however some may not. If they don't, then you can only receive the Yaku for Tanyao unless your hand is entirely concealed.

Note also that some games actually lets you adjust whether or not you want to apply the Kuitan rule in the game's dip switch.

Doras are not required for you to win, but can increase your score since each Dora in your hand counts as 1 Fan. Make sure you understand that a Dora is worth 1 Fan and not a Yaku. You cannot use Doras as a method of fulfilling the 1 Yaku requirement to go out.

On the screen there's the dead pile (pile between the 2 scores). At the start of the round, one tiles is revealed within that pile. The tile revealed in the pile is not the Dora, but the Dora Indicator. The tile following the indicator is the Dora. Confused? Here's an example:

Say the Dora Indicator on screen is a 1-bamboo. The Dora is the following tile, which is the 2-bamboo. If the indicator is a 3-dot like the one in the screenshot above, the Dora is the 4-dot. If the Indicator is a 9-dot, since there are no numbers after 9, it restarts; so the Dora is the 1-dot.

Now how about dragons and winds. Just like the numbers, they have their own sequence as well as shown below:

  • East, South, West, North...
  • White Dragon, Green Dragon, Red Dragon...

A single Dora Indicator is revealed at the start of each round. A new Dora Indicator is revealed on top of the pile for each Kong made during a round by you or the opponent. Usually, Kongs are limited to only 4 per round. Once 4 Kongs are made in a round, no more Kongs can be declared after. These Doras are termed, Kan Doras.

When a round is won by Reach, the tile beneath each Dora Indicator in the dead pile is revealed. They act as Indicators as well, which further increases the amount of Doras in a round by two. These Doras are termed Ura Doras.

Note that in some games, the Ura Dora Indicators underneath Kan Dora Indicators are not revealed after winning by Reach. Only the Ura Dora Indicator beneath the original Dora Indicator is revealed in this case.

Each time you win a round and conclude a match you gain points (high score). Many of the mahjong games in MAME lets you use these points to purchase items which can be used to further increase your chances of winning. Items vary in cost and ability. Many of the items are similar from game to game, though with slight variations. Some of the item's abilities includes:
  • Ability to discard useless tiles in your opening hand at the very beginning of a round and replace them with other random tiles before the round even starts.
  • Ability to change your entire opening hand into a better, rarer, and more complete mahjong hand.
  • Ability to go out on the very next tile right after you Reach.
  • Ability to add more Doras for a given round.

You can purchase multiply items at a time but only one of each type. You can use multiple items per round. However, each item can only be used once. Most of the time, you can choose whether to use a particular item in a given round or save it for a later round. Some items are automatically used when a particular situation comes up during a round as well.

Check the Games section for additional information on game-specific items for certain games.