Roulette is a game of chance that involves spinning a wheel that is divided into 38 segments. a metal ball is tossed into the wheel as it is spinning, and the ball eventually lands in one of the 38 segments. each segment has an associated color. two segments are green. half of the other 36 segments are red, and the others are black. when a balanced roulette wheel is spun, the ball is equally likely to land in any one of the 38 segments.