Outside bets are placed in the boxes around the edge of the roulette layout, hence the name. They win more often and pay less than inside bets, which makes them lower variance and easier to build a staking system around. You can compare every one of them in the roulette payouts tool.
What Outside Bets Are
Outside bets cover broad categories rather than single numbers. The trade-off is simple: the more numbers a bet covers, the more often it wins and the less it pays. This gentle risk profile is why systems like Martingale gravitate to them.
Red or Black
An even-money bet covering the 18 numbers of one colour, paying 1:1. It is the most recognisable outside bet and the classic Martingale target.
Odd or Even
Another even-money bet covering 18 numbers by parity, also paying 1:1 and carrying the same odds as red or black.
High or Low
The third even-money bet, covering 1 to 18 or 19 to 36. Together these three are detailed on the even-money bets page.
Dozens
A dozen bet covers 12 numbers (1 to 12, 13 to 24, or 25 to 36) and pays 2:1. It wins less than half the time, so its recovery math is steeper than an even-money bet, which matters if you try to stake it progressively.
Columns
A column bet also covers 12 numbers, running down one of the three vertical columns, and likewise pays 2:1. Dozens and columns behave the same for odds and payout even though they group the numbers differently.
Payouts and Odds
Even-money bets pay 1:1 on 18 numbers; dozens and columns pay 2:1 on 12 numbers. On a European wheel the zero causes all of them to lose slightly more often than the raw counts suggest, which is the source of the 2.70% house edge that no bet selection can avoid.
Outside Bets vs Inside Bets
Inside bets cover fewer numbers and pay far more, up to 35:1 on a single number, but win rarely. Whether a progression can be used on them is covered on the inside bets page. Outside bets are simply the calmer, higher-frequency side of the layout.
Why Systems Often Use Outside Bets
Betting systems rely on frequent, predictable outcomes so that a staking rule can respond to wins and losses smoothly. Outside bets provide that, especially the even-money ones that fit doubling perfectly. This is why the best Martingale bets and most methods in the strategy betting guide live among the outside bets, even though none of them changes the underlying edge.