Tiu-U (釣魚) – “Catching Fish” requires two sets of Chinese dominoes, i.e. a total of 64 tiles. Two or three people play. 24 tiles are distributed equally between the players. 24 tiles remain in the deck. The rest of the tiles (16 pieces) are placed face up on the table – this is a lake.
For each turn, the player takes one bait tile from his hand and either grabs a fish and takes both tiles for himself, or places his tile in the lake, increasing the number of fish. Then the player takes one tile from the deck and must immediately play it according to the same rules (that is, you cannot put this tile in your hand).
A player can catch a fish with a bait if they have the same number of spots. For example, [5:3] can catch [4:4] and vice versa. The only exception is the tiles of the Supreme Pair, i.e. [4:2] and [2:1], which can fish each other. This exception for [2:1] being able to catch a fish of another value only applies to catching the [4:2], but not to [3:3] or [5:1]. This means that that [4:2] can catch both [2:1] (by the right of the supreme pair) and [3:3] (by the rule of the sum of points), but [2:1] can only catch [4:2].
Another exception is the rule that a player can catch three identical tiles that are already in the lake with the fourth tile. This rule applies only to identical ones, and not to those that have the same amount of points. Using this rule a player can catch three fish with a single bait. There is also a rule that a player can simply add their third identical tile to the two already in the lake, hoping to take all three of them with one bait later.
After all the tiles have been played, the players count the points. Note that the lake will not necessarily be free of fish by the end of the game. Each player divides his catch into small fish and large fish. Small fish are all tiles with less than eight spots. The total number of red spots in a small fish is counted and the total is rounded up to ten (that is, 7 points will be counted as 10, and 11 as 20). The big fish is all the remaining tiles, just count the number of spots and multiply by two. The sum of the points of large and small fish is the player’s points.
An example of calculating a catch from a photo. Ten fish are small, with a total of 12 red spots on them, which is rounded up to 20. Six large fish have a total of 56 spots, multiply by two and get 112 points. Total 132 points.
Rules analysis
In this game, the points are very unevenly distributed between big and small fish. Also the rule that you can add your third tile to the two already existing ones seems meaningless unless some other specific rules are added (for example, about the prohibition of catching these three tiles separately). The game Tiu-U was recorded by the already mentioned Culin, but his work is more than a hundred years old and, unfortunately, Culin did not really try to describe the rules too precisely, so he probably made a mistake or did not add something. Now it is difficult to check.
The game Shi Wu Hu (Fifteen Lakes) corrects all the shortcomings of the “fishing” game. In addition, it seems that the tradition of Shi Wu Hu is still alive.
Sources
Rules on Pagat
Chinese Dominoes GuPai 