The set. 28 tiles, double-blank up to the double-six. Four players, two teams — partners sit opposite (you and North vs. West and East). Play runs counter-clockwise.
The deal. Everyone takes 7 tiles; the whole set is in play. There's no drawing — you match or you knock (pass).
Opening. Whoever holds the 6-6 plays it to start the first hand. After that, the winner of the previous hand opens with any tile.
The play. The line has exactly two open ends. Match either end or pass. When the line reaches the table edge it turns a corner and keeps going. Doubles sit crosswise.
Winning a hand. Empty your hand to domino, and your team scores every pip left in the opponents' hands. If it locks up, the player holding the fewest pips wins it for their team, scoring the losers' pips.
The match. First team to the target takes it. No history to scroll — tracking what's fallen and what your opponents keep passing on is the whole game.