Roulette is a classic casino game built around a spinning wheel divided into numbered pockets and a ball that eventually settles in one of them. Players place bets on the betting layout before the spin, predicting where the ball will land. The game is one of pure chance, with no decisions affecting the outcome once bets are placed.
Wagers fall into two broad groups. Inside bets cover specific numbers or small clusters and pay at higher odds; a straight-up bet on a single number offers the largest payout but the lowest chance of winning. Outside bets cover large groups, such as red or black, odd or even, or ranges of numbers, and pay less but win more often.
As a concrete example, a player might place a single chip on a particular number and another on red. If the ball lands on that exact number, the straight-up bet pays at its fixed multiple; if it lands on any red pocket, the red bet pays even money. Both can win on the same spin if the chosen number happens to be red.
The crucial structural feature is the presence of one or more zero pockets, which are neither red nor black and cause most even-money bets to lose. This is the source of the house edge, because payouts are calculated as if the zeros did not exist. A single-zero wheel therefore offers a lower edge than a double-zero wheel.
A common misconception is that tracking previous results, such as a run of reds, reveals which colour is “due”. Each spin is independent, so past outcomes carry no predictive value; believing otherwise is the gambler’s fallacy. The wheel type, available bet types, any special rules that soften the edge on even-money bets, and table limits vary by operator and jurisdiction, so players should check the specific game before staking.