Domino is the name of a game played with a set of small rectangular wood or plastic blocks marked with dots resembling those on dice. The dominoes are stacked on end in long lines, and when one is tipped over, it sets off a chain reaction that leads to the toppling of all the others. Many variations of the game exist, but most involve a player scoring by adding up the pips on his or her tiles at the end of a hand or a game. The term domino also refers to a political situation where an event or decision triggers a series of reactions, like the falling of dominoes.

Whether they’re used as toys or for building structures, the domino effect is a simple but powerful concept. A single action, such as a toppling domino, causes a sequence of events that have far-reaching consequences. The process is often compared to the firing of neurons in a brain, which can be triggered by an initial stimulus and lead to much larger, more complex reactions.

In the simplest form of domino, players begin with a line of seven or more adjacent dominoes. Each player then chooses a domino to add to his or her own set. Once all the players have chosen their dominoes, play begins. If a player cannot place his or her chosen domino, he or she passes his turn to the player to his or her right.

The most common domino sets include double six (28 tiles) and double nine (55 tiles). Larger domino sets are available, and they are popular for games involving more than four players. These large sets introduce ends with more pips, increasing the number of unique combinations and therefore the number of possible tiles.

When a player plays a domino, the other players can see it, and they may try to match its pips with those of their own tiles. The first player to make a matching pair wins the hand or game. In some games, a player may only use the domino with a specific number of pips. If a player uses a domino with more than one number of pips, he or she must pay for it.

A player who does not want to continue a hand or game may pass his or her turn by knocking the table with a domino, which is known as “setting” or “laying down” the lead. In some games, a player who does this must pick up the dominoes that have been placed on the table and return them to the stock before he or she can proceed.

Some games allow players to buy dominoes from the stock, which is a group of unplayed dominoes. When a player draws a domino from the stock, he or she must sit in that seat until the other players play their hands. Some games require players to sit opposite each other.

Some players have difficulty reading the pips on dominoes. To help, some manufacturers produce dominoes that feature more easily readable Arabic numerals on their sides. Alternatively, some players prefer to use a pencil to mark the pips on their own tiles to identify them easier.