The block game
If you cannot play, you pass. The tiles left in the boneyard stay out of the round.
Block is the simplest and probably the most common domino game, in Pagat's wording. Most of the tiles are dealt to the players, and the tiles that remain in the boneyard are not used. pagat.com Many of the games we associate with dominoes are quite modern. The block games seem to be the oldest of the European games. But Muggins dates from the early 20th century. pagat.com
On a double-six set, Pagat's representative block deal is: 2 players get 7 tiles each; 3 players get 5 tiles each; 4 players get 5 tiles each. The rest stay in the boneyard and are not used in the round. pagat.com
How many tiles does each player take?
Britannica Kids, describing a simple block game, says each player then draws seven dominoes. Pagat's representative block deal on a double-six set is seven tiles for two players, and five each for three or four. Its representative draw deal is seven each for two or three players, and six each for four. Pagat also lists "different numbers of tiles in the hands" as a common variation. Seven each is one usual deal, not the only one.
Players take turns placing tiles on either end of the train. Doubles are played across the line, but are not spinners. A player who cannot play passes. pagat.com
The round stops when one player plays their last tile or when nobody can play. The lead for the next round passes to the previous leader's left. pagat.com
Scoring
At the end of the hand, each player gets the total number of pips in his hands. The lowest scoring player is the winner and is credited with the sum of the scores of the losers, minus his own total. If there is a tie for lowest score, then nobody gets a score. pagat.com The game is played for 100 points in a two player or partnership game, and for 61 points in a three or four handed game. This convention allows a cribbage board to be used for keeping scores. pagat.com
Pagat lists variations, including different numbers of tiles in the hands, and determining the lead by requiring that the highest double be led first. pagat.com
How is a hand scored, and what is a game?
Britannica Kids says the winner is the player who goes out, or who has the fewest spots left, and that one player's score is the number of spots on the opponent's unplayed dominoes; a game may be 50 or 100 points. Pagat's representative block and draw rules credit the lowest-scoring player with the sum of the losers' pip totals minus that player's own total, and play a game to 100 points (two players or a partnership) or 61 (three or four), so a cribbage board can be used. Pagat also records early accounts in which a win is just 1 point, and many other local scoring methods. We treat Pagat's representative rules as one clear system, not the only system.
The other basic game is draw.