A slot machine is commonly found at bars and casinos. It is used for gambling purposes. They were invented in the United States in 1891. The original slot machines had a lever that you would pull down and if three numbers or items matched, you would win money. Similar to pinball machines, they have different themes in modern times. The oldest themed slot machine was a Harley-Davidson one. They currently make themed slot machines which feature The Simpsons, Big Buck Hunter, and rock and metal bands such as Megadeth and Kiss.