A domino is a small rectangular block, about the size of a playing card, with one side bearing an arrangement of dots resembling those on dice. The other side is blank or identically patterned. Dominoes are usually made of wood or plastic, but they may be made of other materials, as well. Dominoes are used in games to build lines, curved lines, grids that form pictures when they fall, stacked walls, or even 3-D structures like pyramids and towers. Dominoes can also be used to make patterns, which can include straight lines and arcs, curved lines and arrows, or a combination of the two. In some games, the number of pieces forming a pattern determines the winning outcome.

Dominoes can be played individually or in groups. In a group, the first player begins by placing his or her domino on the edge of a line of tiles. Players then take turns playing their tiles, following a set order of play that varies according to the game being played.

When all of the tiles have been placed, the player who holds the highest double (or, in some cases, a higher single) makes the first play. In some games, the rules specify that a player must place a tile on a domino with a value equal to or greater than the number of pips on that domino. Other games have rules that specify that the player must draw new hands if he or she cannot make a play immediately after a domino is drawn.

There are many different types of domino games, and the rules vary by region and country. There are even a few games that have the same name in different parts of the world, but differ by a significant amount of detail, such as the way that the tiles are placed on the table or the way that scoring is calculated.

The word domino derives from the Latin term for a “pip.” This word was used to refer to a piece of wood or a rectangular clay block, similar in shape to a die, that represented a number when thrown. It was used as a gambling device, but later it came to be used in the sense of a whole unit of something. This led to the use of the phrase domino effect, meaning a situation that results in a series of events or effects, all of which are proportionally related to one another. For example, if a student fails a test, it can affect the entire class and ultimately lead to other problems in the school. The teacher can then try to fix these issues, but it’s difficult to do anything that will prevent the domino effect from happening again. This is why it’s important to plan ahead and keep the students on track with their studies.