Domino toppling is the activity of standing up dominoes in sequence known as a domino run and then knocking down the first one in line to strike the next, which knocks that down to strike the next, and so on, creating a chain reaction also called the domino effect. A competition between two or more players to be first to have all one's dominoes fall is sometimes called a domino rally. If domino toppling is demonstrated to an audience it is called a domino show.