Guoshi Wushuang is the Japanese name for Mahjong, which is also the so-called Thirteen Units.

The Thirteen Units are a sum composed of three ordinal tiles, 1 and 9, seven character tiles and a pair of trump tiles. Don't count the five gates together, the gate clear in front of the gate, the single fishing general, and the mixed unit nine, you can make up your own plan without asking for help.

The thirteen units must be complete in the five categories of ten thousand, strips, tubes, winds and arrows. According to the principle of non-repetition, the five categories are not included.

Thirteen units must be cleared in front of the door, but according to the new rules, you can add up by yourself and do not ask for help.

If you listen to the 13th unitary tile at one time (that is, there are 12 different unitary tiles in your hand, and one of them is a pair, listen to the 13th unitary tile), then because there is already a pair of generals, Yes, the monotonous general and the 13th card are not counted.

And if it is a thirteen unit with thirteen sides (that is, all 13 unit nine cards are in the hand, and any one), then although there is no trump card in the hand, it does not meet the requirements for single fishing. Listening to one piece alone (for example, 8999 and 8 are not counted as monotonous generals, because they can also be combined with 7), so they are not counted as single fishing generals.

Extended information:

Japanese mahjong rules:

In Japanese mahjong, the thirteen units are often called "unparalleled national warriors", and you can listen to thirteen types of mahjong. The drawing form of the Yaojiu tiles (that is, holding one of each of the 13 types of Yaojiu tiles) is called the unparalleled thirteen faces of the National Scholar. Generally speaking, the National Scholar Wushuang is "full of service"; most of the Thirteenth Edition of National Scholar Wushuang has double the service limit, and there are also rules that only count the completion of the service.

A few rules allow the national warrior Wushuang to grab the hidden kong, and a very few rules treat the thirteenth unit grabbing the hidden kong as double the full battle.

There are very few rules that open the "Zhenting Ban Rules" for the National Scholars' Unparalleled Thirteen Sides, and treat the non-Zhenting Thirteen Sides as a full battle, and the Zhenlist Thirteen Sides as a full service.