The bet that covers half the wheel, not one number
You sit down at a roulette table, buy in, and the dealer pushes a stack of coloured chips toward you. The layout in front of you is split into two zones. The inside is a grid of numbers. The outside is a ring of boxes around that grid, and those boxes are where a new player usually starts, because they win more often than a straight-up number. That frequency has a cost, and understanding it is the whole game.
An outside bet is any wager placed on the boxes around the numbered grid. Instead of betting that the ball lands in one specific pocket, you are betting that it lands somewhere inside a group: a colour, a parity, a half of the numbers, or a block of twelve. The payout is smaller because the group is larger.
What each outside box means
The boxes are labelled, but the labels assume you already know the wheel. On a European wheel there are 37 pockets, numbered 0 to 36, with a single zero. On an American wheel there are 38, because a double zero is added. The extra pocket changes the arithmetic on every bet, including the outside ones.
| Bet | What it covers | Payout | Why it is called outside |
|---|---|---|---|
| Red or black | All pockets of one colour | 1 to 1 | Placed on the colour box, not on numbers |
| Odd or even | All odd or all even numbers | 1 to 1 | Placed on the parity box |
| Low or high | 1-18 or 19-36 | 1 to 1 | Placed on the half-wheel box |
| Dozen | 1-12, 13-24, or 25-36 | 2 to 1 | Three boxes marked as dozens |
| Column | A vertical column of twelve numbers | 2 to 1 | Box at the foot of each column |
The zero is the part nobody mentions when they explain the colour bet. On a European wheel, the zero pocket is green. A bet on red loses when the zero arrives, and the same is true for black, odd, even, low and high. The zero is not a half of anything. That is the house edge doing its work.
The sequence of a round, from buy-in to settlement
You buy in at the table, not at a cashier window. The dealer exchanges your cash for roulette chips, which are different from the chips used at other tables and carry no printed value. Tell the dealer what denomination you want each chip to be, and that value stays attached to your colour for the session.
When the dealer opens betting, you place chips on the outside boxes. You do not need to touch the numbered grid at all. Once the ball is spinning, the dealer calls no more bets, and from that moment nothing on the layout may move. The ball drops, the dealer marks the winning number, and losing bets are cleared first. Winning outside bets are then paid at the odds printed on the layout: even-money bets at 1 to 1, dozens and columns at 2 to 1. You leave the winning bet in place if you want it to ride, or the dealer returns it with your winnings.
How the house edge differs between the two wheels
The payout on an outside bet is fixed, but the chance of winning is not, because the wheel has pockets that belong to no outside group. On a European wheel, a red bet wins on 18 pockets and loses on 19, because the zero is green. The house edge and RTP are complements: they sum to 100% for the same game. The edge on that bet comes from the one pocket that pays nobody.
On an American wheel, the double zero adds a second green pocket. The same red bet still wins on 18 pockets, but now loses on 20. The payout has not changed, so the edge has widened. The outside boxes look identical on both layouts, which is why the wheel type matters more than the bet name.
| Wheel | Pockets | Green pockets | Effect on an even-money outside bet |
|---|---|---|---|
| European | 37 | 1 | 18 winning pockets, 19 losing |
| American | 38 | 2 | 18 winning pockets, 20 losing |
Dozens and columns carry the same structural problem. A dozen covers 12 numbers. On a European wheel, 12 pockets win and 25 lose, while the payout is 2 to 1. The mismatch between the payout and the true odds of the group is the edge, and it is built into the layout, not into how you bet.
The decision points that are yours
Outside roulette gives you fewer decisions than most table games, and that is part of its appeal. You choose which group to bet, how much to stake, and whether to leave a winning bet in place. You do not choose when the ball is released, and no choice you make after the spin changes what the ball does.
The meaningful decision is bet selection. Even-money bets lose less often than dozens, but they pay less when they win. Dozens pay more but miss more often. Neither is better in a way that removes the edge; they are different shapes of the same negative-expectation game. A session built on red and black will produce many small outcomes. A session built on dozens will produce longer dry spells and larger single wins. Volatility describes that difference, and volatility does not change a game's RTP.
Stake sizing is the other decision. Because outside bets resolve quickly, the number of decisions per hour is high, and a fixed stake per spin turns into a large total amount wagered over an evening. The total wagered, multiplied by the edge, is what the game costs on average over the long run. The player controls the total wagered through stake size and session length, not through the bet pattern.
Mistakes that cost new players more than the edge does
The first mistake is buying in and not saying a chip value. The dealer will assign one, and it may be higher than you intended. State the denomination when you put cash on the table, before the dealer colours you up.
The second is moving chips after the no-more-bets call. A late hand on the layout, even an innocent one, will be corrected, and repeated corrections mark you as a player who does not know the procedure. Keep hands off the felt once the ball is in motion.
The third is treating the zero as a push. It is not. On every outside bet except a direct wager on the zero itself, the green pocket is a loss. New players sometimes believe an even-money bet on red simply does not count when zero arrives. It counts, and it loses.
What a strategy chart can and cannot do here
Roulette has no decision chart in the sense that blackjack does. In blackjack, a published basic-strategy chart derives from the specific rule set in use: deck count, dealer stand rules, doubling and splitting rules. Change one rule and parts of the chart change. Roulette offers no comparable decision tree, because the player makes no choices after the bet is placed.
What roulette does have is a fixed payout schedule, and that schedule is the strategy. The only information a player needs is which wheel is in front of them and what each box pays. Everything else is a betting system, and no betting pattern changes the built-in edge of a negative-expectation game. Progression systems that double after losses redistribute outcomes rather than remove the edge; they change the shape of the session, not its long-run average.
FAQ
Can I place outside bets and inside bets on the same spin?
Yes. The layout allows both zones to be played at once, and many players combine a colour bet with a straight-up number or two. Each bet settles independently against the same winning number, so a spin can win on one zone and lose on the other.
Does the zero lose on all outside bets?
On the standard outside boxes, yes. Red, black, odd, even, low, high, dozens and columns all lose when a green zero arrives, because the zero belongs to none of those groups. Some tables offer special rules that alter this, but those rules are printed on the layout or in the table's terms, and they are not the default.
What is the difference between a dozen and a column?
Both cover twelve numbers and both pay 2 to 1, but they group the wheel differently. A dozen is a consecutive block: 1-12, 13-24, or 25-36. A column is a vertical line through the layout, taking every third number. The edge is the same on both, but the distribution of numbers across the wheel differs, so the two bets feel different in play.
If you or someone you know has a gambling problem, call the helpline printed in the footer below.
Play responsibly
Gambling should be treated as paid entertainment, never as a way to earn income or recover losses. 1-800-MY-RESET (1-800-697-3738)
18+ or 21+ depending on where you are; follow the minimum age that applies to you.
This article is general information about how these mechanics work. It is not legal advice and not a recommendation to gamble or to use any particular operator. Availability and legality differ by jurisdiction — check the rules that apply where you are.