How to play roulette

What is roulette?

Roulette is a wheel game. The dealer spins a wheel in one direction and rolls a small ball the other way, and the pocket the ball settles in decides every bet on the table.

You bet on where the ball will stop. That can be one exact number or a large group of numbers, and the size of the group sets the payout.

This guide describes single-zero roulette, the wheel with 37 pockets. No rule that returns part of a losing even-money bet is in use here.

The wheel and betting layout

The wheel has 37 pockets: the numbers 1 to 36, half of them red and half black, plus a single green zero.

The layout printed on the table shows the same 37 numbers in a grid, with wider boxes around the edge for the larger groups.

Inside the box for 5, the chip covers one number. On the line between 8 and 9, it covers two. On the outside line beside 13, at the end of that row, it covers 13, 14 and 15. On the point where 10, 11, 13 and 14 meet, it covers four. A six line chip sits on the same outside line where two neighbouring rows meet and covers six numbers.

The position of your chip is the bet. A chip inside one box backs that number alone, and a chip on the line between two boxes backs those two numbers.

A chip on the point where four boxes meet backs those four. Streets and six lines are placed on the outside line beside the first number of the row, and are described below.

How a spin works

You place chips on the layout while betting is open.

The dealer spins the wheel, releases the ball against the direction of the spin, and at some point announces that betting is closed. No chip may be placed or moved after that.

When the ball comes to rest, the dealer marks the winning number on the layout, clears the losing chips and pays the winning ones.

Inside and outside bets

Inside bets sit on the numbered grid and cover between one and six numbers.

A straight covers one number. A split, placed on the line between two boxes, covers two. A corner, placed where four boxes meet, covers those four.

A street covers the three numbers of one row and a six line covers two neighbouring rows. Both sit on the outside line beside the first number of the row rather than inside the grid.

Outside bets sit in the boxes around the grid and cover large groups. A dozen covers twelve consecutive numbers, a column covers the twelve numbers of one column, and red, black, odd, even, 1 to 18 and 19 to 36 each cover eighteen numbers.

Zero is green. It is outside the dozens, the columns and all the even-money groups listed here, so those bets lose when zero lands.

Payouts and winning probabilities

A payout of 35:1 means 35 units are added to a winning 1-unit bet, and the bet itself stays with you.

Bet	Numbers covered	Net payout	Win probability
Straight	1	35:1	1/37
Split	2	17:1	2/37
Street	3	11:1	3/37
Corner	4	8:1	4/37
Six line	6	5:1	6/37
Dozen or column	12	2:1	12/37
Red, black, odd, even, 1 to 18, 19 to 36	18	1:1	18/37

Reading across a row shows the trade. Covering more numbers wins more often and pays less each time.

A worked bet

You place 10 units on red.

If the ball lands in a red pocket you earn 10 units, and 20 units come back to you including your stake. If it lands in a black pocket or in the zero, the 10 units are lost.

Eighteen of the 37 pockets are red, so the chance of winning this bet is 18/37 and the chance of losing it is 19/37.

What zero means for the odds

The payouts are built as though the zero were not there. A straight covers 1 pocket in 37 but pays 35:1, and red covers 18 pockets in 37 but pays 1:1.

The red bet shows the gap directly. Take a wager of 1 unit and assume every one of the 37 pockets is equally likely:

Expected net result = (18/37 × 1) + (19/37 × -1) = -1/37 unit per spin.

That is an expected loss of about 2.70% of the stake.

Every standard bet on this wheel carries that same figure, because each of them is priced as if only 36 pockets existed.

Winning probability and expected return are two different things. A straight wins about once in 37 spins, and its long-run cost per unit staked is the same 2.70% as an even-money bet that wins nearly half the time.

That 2.70% is a long-run average, not a forecast for any block of spins. A short run can end well ahead or well behind it, and no way of choosing or sizing bets changes the figure.

Rules to check before applying this guide

Everything above assumes a wheel with one zero and no special rules on even-money bets.

A wheel with both a zero and a double zero has 38 pockets while paying the same amounts, so the numbers in this guide do not apply to it.

Some single-zero tables return half of a losing even-money bet, or hold it for the next spin, when the ball lands in the zero. Those rules change the arithmetic above, so read the table sign first.