Dominos is a game featuring little bricks with dots printed on them. They are also the starting ground for many cases of OCD, and a pizza chain.
While many people may not know it, Dominos was a game to start out. In the game, each player is given a certain amount of Dominos, the remaining are placed in a pile and a starting domino is places in the middle. It is then that the players take turns placing dominoes with a matching number of dots together. However, the only people who really play the game in earnest are old people, the kind of kids who are members of "chess leauge" and families getting together for what I like to call "Get together and fight with the kids while pretending to have 'fun'", otherwise known as "Family Game Night'.
They aren't happy because they won, they're happy because its chille night!
Most other people simply decide to place the dominos on end, closely together and tip one over and watch the others fall down as a result. This is known as "Domino Lines" or simply as "Dominoes". This can either be done in a simple yet gratifying way, or in a way that broadcasts to the world how much extra time you really have on your hands. There are even domino line contests. Confusingly enough, in these contests, you dont have to use specifically dominos.