Classic Dominoes 2×2 — Rules

Classic dominoes for two teams, close to the Russian "Kozel" (Goat). Points are penalties: the team that reaches 101 loses.

1. At a glance

Each player gets 7 tiles. A hand with 5+ doubles, or 6–7 tiles of one number, is reshuffled automatically.
The holder of 1-1 opens the first hand of the game with it.
Every later hand is opened, with any tile, by the player who went out last time; after a blocked game, by the last player who played a non-double.
Play a tile that matches one of the two open ends. Doubles go crosswise.
If you can play, you must; otherwise you pass ("knock").
The hand ends when a player plays their last tile ("domino!") or nobody can play (a blocked game).

The losing team adds the pips left in both its hands to its own score. The winners add nothing; the tiles of the winner's partner do not count.
A lone 0-0 left in a player's hand counts 10.
Blocked game: the team with the lower total of both hands wins; the other team takes its own total. On a tie the points "hang" and go to the next team penalized.
Rule of 13: while a team's score is 0, a hand worth less than 13 is held, not written, and added once it takes 13 or more in one hand. If the other team starts holding points, the first team's are cleared. It does not change who opens the next hand.
Example: you go out. Your opponents hold 6-5 and 3-1 + 2-0: they write 17.

As soon as a team reaches 101 or more, it loses. Each player has a 15-minute clock for the whole game; if one runs out of time, their team loses.