Outside bets are those placed in the eleven boxes around the numbered boxes on the roulette layout. You have five options for outside bets: dozens, columns, even/odd, red/black, or high/low. The payouts on these bets are lower than on inside bets because you cover more pockets; instead of having a 1-in-38 shot at winning, you have up to an 18-in-38 shot.
Dozens and Columns Bets
Columns and dozens bets usually pay 2 to 1. Each of these bets lets you cover twelve numbers on a spin. In a dozen bet, also known as an “any twelve” bet, you choose a set of twelve consecutive numbers — 1 through 12, 13 through 24, or 25 through 36.
Place your chip on the box marked “1st 12,” “2nd 12,” or “3rd 12.” If the ball lands on any number within your dozen, you win. If it lands on 0 or 00, you lose.
Column bets also give you twelve potential winning numbers, but they aren't consecutive. You place your bet on the column headed with 1, 2, or 3; your chip goes in the box underneath the column, which usually reads “2 to 1.” If the winning number falls in the column you've chosen, you win. Again, 0 and 00 are losing numbers for this bet.
Even-Money Outside Bets
The other outside bets in roulette are red/black, even/odd, and high/low. Each of these is an even money wager, paying 1 to 1 if you win. The boxes for these bets are found farthest to the left of the numbered boxes. Again, 0 and 00 are losing numbers for any of these options.
These even-money bets are just what they sound like. You bet that the ball will land in either a red or black pocket, that the winning number will be odd or even, or that the winning number will be high (19 or higher) or low (18 or lower).
There are eighteen red pockets and eighteen black pockets, eighteen even numbers and eighteen odd numbers, and eighteen low numbers and eighteen high numbers, so it's easy to think that the probability of the ball landing on red or black, odd or even, or high or low is fifty-fifty. Because of the 0 and 00 pockets, which are both green, the probability of winning on any of these even-money bets is closer to 47 percent.