David Pritchard on the allure of the second most popular pub game

Dominoes are widely played in working men's clubs throughout the UK. They are also the second most popular pub game after darts. Strictly speaking, dominoes are not a game at all, but, like playing cards, are the tools for many different games.

The origin of the word is obscure. One rather unlikely theory is that it is derived from a mask, sometimes called a domino, because of the similarity of the 1:1 tile to a mask with its two eye holes. The origin of the game is also obscure; all we know for certain is that it surfaced in Italy in the middle of the 18th century and may have come from the East.

Dominoes are oblong tiles, usually of wood or plastic, divided into two, each half of the tile depicting a number, represented by dots like those on dice, or simply blank. A set of dominoes is commonly called a pack. There are three packs in general use, the double-six, double-nine and double-12, the last two being less common in the UK. The number refers to the highest tile in the set; thus the 6:6 tile is the highest domino in the double-six pack.

This is the pack in use for the two pairs games being played in the Olympiad - the Block game and Fives & Threes, both partnership games. A double-six pack is composed of 28 tiles, also known as bones or stones, which represent every possible throw of two dice plus blanks (imagine dice falling awkwardly so that no face is uppermost). Both games are played in much the same way but with different methods of scoring. Partners sit opposite each other. The tiles are shuffled face-down and each player draws six, usually held in the hand. Each player in turn, if able to do so, places a domino on the table to form a single line of tiles (which may go off at right angles so as to avoid falling off the table).

Each tile must be placed so that the half that abuts the line matches the open half of one or other of the tiles at either end of the line. Doubles are normally placed at right angles to the line, but this has no effect on the play. Despite their apparent simplicity, domino games are highly skilful and are normally played at speed. In the Block game, the object is for one player or team to go out; ie, to get rid of all their dominoes.

In Fives & Threes, the object is to score points by placing a tile so that the exposed faces at either end of the leg are divisible by five or three or, better still, both. Thus if a player opens with a double-six (6:6) and the next player is able to put down the 6:3, the total spots at the ends of the leg are 15 (6:6 plus 3), which scores the maximum eight points (five divides into 15 three times and three divides into 15 five times, three plus five equals eight). If the next player now puts down the double-three, the ends total 18 spots for a score of six points (18 divided by three). The highest scoring team is the winner.