This version of dominoes is generally referred to as All Fives. It is a 2 player game where the winner is the first player to reach 200 (or 400) points.
After shuffling the dominoes, each player draws 7 tiles to make up their hand. The remainder of the tiles make up the boneyard (or "stock"), and are drawn as needed. The player with the highest double automatically goes first and is forced to play their highest double tile. If neither player has a double tile, the player with the heaviest hand (most pips) goes first and may play any tile they wish. Players take turn placing tiles on the board, matching up numbers on any of the 4 ends. If a player is unable to play, he must draw from the boneyard until he can play a tile on the board. The first double played in All Fives becomes the "Spinner" and can be played in 4 directions.
Scoring in All Fives is done at the end of each turn and at the end of each game. When completing a turn, all the ends are added up and if the sum is a multiple of 5, the player scores that many points. Double tiles that are located on one of the ends are counted as 2X, so a 6|6 tile is worth 12 points. A blank end tile counts as 0.
If a player is able to get rid of all their tiles or both players are blocked, the player with fewer pips scores the difference of their total pips minus opponent pips. Whoever wins the hand then plays first in the next hand and the game continues until a player reaches 200 (or 400) points.