Online roulette, by the math
The biggest choice you make in roulette happens before the wheel even spins: which game you pick. If you choose European or French roulette, you are playing a game where the casino has a small advantage of 2.7%. If you pick American roulette, the house advantage jumps to 5.26%, which is nearly double the cost. In this guide, we will explain how these three games work, look at the math behind every bet, and show why betting systems do not actually help you win in the long run.
You can find more details on how the wheel works and a full payout table in our main games guide.
Roulette at a glance
Here are the important facts to know before you start playing.
House edge
2.70%
European single-zero; 5.26% American double-zero
French (La Partage)
1.35%
Half stake back on outside losses to zero
Variants
4 main
European, American, French, Lightning
Wheel pockets
37 or 38
EU = 37; US adds the 00 for 38
Lightning multipliers
50 - 500x
Random hits on straight-up bets
Top providers
Evolution
Lightning Roulette is the live flagship
Live dealer
Yes (very popular)
Second-largest live category after blackjack
Best fit
Live for atmosphere
RNG is mathematically identical, less engaging
A brief history of roulette
Most people believe roulette started in 17th-century France. A man named Blaise Pascal was trying to invent a machine that moved forever without power. He failed, but he created an early version of the roulette wheel. By the late 1700s, people were playing a game very similar to modern roulette in Paris. Later, in 1842, the Blanc brothers used this wheel to build the famous casino in Monte Carlo.
The American version started in the gambling halls of New Orleans in the 1800s. Casinos added a second green pocket (the 00) to give themselves a bigger advantage. This version eventually moved back to Europe too. Today, the single-zero wheel is most common in Europe and Asia, while the double-zero wheel is common in the United States. Online, you can usually find both and choose which one you want to play.
The math of the game has stayed the same for hundreds of years. Whether you play on a modern screen or a real wooden wheel, the chances are identical. The only thing that has really changed is how fast you can play. A live table might have 40 spins an hour, but a computer version can have 300. The faster you play, the faster you are likely to lose your money.
The three wheel variants and why the choice matters
Most online casinos have three different types of wheels. The differences might seem small, but they decide how much money the casino takes from you over time. Choosing the wrong wheel means you are paying much more for the same game.
European
37 pockets · one zero
2.70%
house edge on every bet
This wheel has 37 pockets and one zero. The casino has a 2.7% advantage on every bet. This is the standard wheel you will see most often. It has numbers from 1 to 36 and one green zero. This is the version you should play most of the time.
French
37 pockets · La Partage / En Prison
1.35%
house edge on even-money bets
This uses the same 37-pocket wheel as the European version but has a special rule called La Partage. If you bet on something that pays even money (like Red or Black) and the ball lands on zero, you get half your bet back. This makes the casino advantage drop to 1.35%, which are some of the best odds you can find.
American
38 pockets · 0 and 00
5.26%
house edge on every standard bet
This wheel has 38 pockets because it adds a 00. The payouts are the same as the European version, but because there is an extra pocket, you are more likely to lose. The casino advantage is 5.26%. You should avoid this game unless there are no other options.
Pro tip: read the lobby label carefully
Casinos do not always make it clear which version they are running. A game just called "Roulette" might be American or European. Look at the picture of the wheel or check the rules before you start. If the wheel has two green zeros, it is the American version, which will cost you more money in the long run.
Inside bets - the high-payout, low-probability options
Inside bets are bets placed directly on the numbers. These are harder to win, but they pay out more money when you do. On a European wheel, the casino always has the same 2.7% advantage no matter which numbers you pick.
| Bet | Payout |
|---|---|
| Straight up | 35:1 |
| Split | 17:1 |
| Street | 11:1 |
| Corner | 8:1 |
| Six line | 5:1 |
| Five number (US only) | 6:1 |
Outside bets - the lower-variance options
Outside bets are placed on the areas around the numbers. You win these more often, but the payouts are smaller. These are better if you want to play for longer without losing your money as quickly. The best odds on the table are French outside bets because of the La Partage rule.
| Bet | Payout |
|---|---|
| Red / Black | 1:1 |
| Even / Odd | 1:1 |
| High / Low (1-18 / 19-36) | 1:1 |
| Dozens (1-12, 13-24, 25-36) | 2:1 |
| Columns | 2:1 |
Nearly every bet on a European wheel has the same house advantage of 2.7%. The only thing that changes is how often you win and how much you get paid. High-risk bets pay a lot but happen rarely, while low-risk bets pay a little but happen often. Over a long time, you will likely lose the same percentage of your money either way.
How the house edge actually works
The house advantage is just the way the casino makes sure it makes money. Imagine you bet on one number. There are 37 pockets on the wheel. You have a 1 in 37 chance of winning. If you win, the casino pays you 35 times your bet plus your original stake, so you get 36 units back.
To be a completely fair game where no one has an advantage, the casino would have to pay you 36 to 1. Because they only pay 35 to 1, they keep a small amount of money for themselves every time the wheel spins. That difference is the house edge.
On an American wheel, there are 38 pockets but the payout is still 35 to 1. This means the casino keeps two units instead of one, which makes their advantage twice as large. The extra 00 pocket is basically a hidden fee you pay on every single bet.
French roulette is different because of the La Partage rule. If you bet on Red and the ball lands on zero, you get half your money back. This cuts the casino advantage in half, making it only 1.35% for those specific bets.
The betting systems, and why none of them work
Many people try to use systems to beat the game, but none of them actually work. These systems just change how you lose your money. They might help you win small amounts often, but they usually lead to one big loss that takes all your profit away. You cannot use a pattern of bets to change the math of the wheel.
Martingale (double after loss)
This is where you double your bet every time you lose, hoping that a win will cover your losses. The problem is that your bets get very big very quickly. If you lose seven times in a row, a $10 bet becomes a $1,280 bet. Eventually, you will either run out of money or hit the maximum bet allowed by the casino. It feels like it works until you hit a losing streak, and then you lose everything.
Fibonacci (sequence-based progression)
This uses a specific string of numbers to decide your bet size after a loss. It grows more slowly than the Martingale, but it has the same problem. A long run of losses will eventually require bets that are too high to place.
D'Alembert (linear progression)
You increase your bet by one unit after a loss and decrease it by one after a win. This is based on the idea that wins and losses will eventually even out. However, the wheel does not remember the last spin. Each spin is a new event, so the odds never change in your favor.
Labouchere (cancellation system)
This is a complicated system where you write down a list of numbers and cross them off as you win. It is just another way to manage your bets, and it can still lead to very large losses during a bad streak.
Paroli (reverse Martingale)
Here, you double your bet after you win. It is safer than the original Martingale because you are not chasing losses, but you will still lose money over time because of the house edge.
The truth is that betting systems are just for fun. They can give you a plan for your session, but they do not change your chances of winning. Anyone who tells you they have a "guaranteed" way to win at roulette is not telling the truth.
Live dealer roulette and the multiplier products
Live dealer games are streamed from a studio with a real person spinning a real wheel. The math is exactly the same as the computer versions. The main difference is that the game is slower, which can actually be better for your bankroll because you are placing fewer bets per hour. Some live games also add extra prizes called multipliers.
Classic live roulette (Evolution, Pragmatic Live, Playtech)
This is a normal game with a real dealer. The odds are the same as any other European wheel. People play this for the social experience, as you can often chat with the dealer and other players.
Lightning Roulette (Evolution)
In this game, a few random numbers are given big multipliers every spin. If you bet on one of those numbers and it wins, you can get a much bigger payout. To pay for these big prizes, the casino takes a slightly larger advantage of about 2.95%.
Mega Roulette (Pragmatic Live)
This works almost exactly like Lightning Roulette. It has multipliers up to 500x. The house advantage is also a bit higher than normal at around 3%.
XXXtreme Lightning (Evolution)
This is a more intense version of Lightning Roulette. The multipliers can be much higher, sometimes up to 2,000x. This is a very "bumpy" game where you can win big but will likely lose more often.
The roulette-specific pitfalls that cost players money
Most people lose more money than they should because of a few simple mistakes. Avoiding these is the easiest way to make your money last longer.
1. Playing American without checking
This is the most common mistake. Always look at the wheel before you play. If it has two green zeros, do not play it. It costs you much more money than the European version.
2. The Five Number bet on American wheels
This is a specific bet on the numbers 0, 00, 1, 2, and 3. It has the worst odds on the entire table. Never place this bet.
3. Chasing with a betting system on a tight bankroll
Systems like the Martingale require a lot of money to work. If you only have a small amount of money, you will likely lose it all before you can finish the system. If you want to use a system, make sure you have a very large bankroll and that the table allows high enough bets.
4. Reading patterns into independent spins
Many people think that if Red has won five times in a row, Black is "due" to win. This is not true. The wheel has no memory. Every spin has the same odds as the one before it. The boards that show the last few numbers are just for interest and do not help you predict the future.
Responsible play, applied to roulette
Roulette can seem like a slow game, but you can actually bet a lot of money very quickly. An hour of play can easily involve over $1,000 in bets. You need to be careful about how much you are actually spending.
A good rule is to decide exactly how much you are willing to lose before you start. You should also decide how much profit would make you happy enough to stop. Once you hit either of those numbers, walk away. Do not start using betting systems to try and win back money you have already lost.
The biggest danger in roulette is believing that a system can help you win back losses. Doubling your bets after a loss is a very risky way to play. It can turn a small loss into a huge one very quickly. The best way to stay safe is to use a fixed bet size that you can afford and stick to a strict limit on how much you spend. Our responsible gambling page has more advice on how to keep your playing under control.
Common questions about roulette
Here are the questions we get asked most often about roulette and the different versions of the game.
What's the difference between European, American, and French roulette?
European roulette has 37 pockets and one zero. American roulette has 38 pockets because it adds a second zero (00), which makes it much harder to win. French roulette is like the European version but gives you half your money back on some bets if the ball lands on zero. Always choose European or French if you can.
Are betting systems like Martingale ever profitable?
No. These systems might help you win for a short time, but eventually you will have a long run of losses that ruins everything. The casino sets maximum bet limits specifically to stop these systems from working. The house advantage always stays the same, no matter how you change your bet size.
What's the worst bet on a roulette table?
The "Five Number" bet on an American wheel is the worst bet you can make. In general, any bet on an American wheel is worse than the same bet on a European wheel. The most important thing you can do is avoid wheels with two green zeros.
Are RNG (digital) roulette wheels rigged?
As long as you play at a licensed casino, the games are fair. The software is checked by independent companies to make sure the results are truly random. Every number has the same chance of winning on every spin. We only recommend casinos that have these safety checks in place.
Can you "find a biased wheel" online?
No. Online computer games use random numbers, so there is no physical wheel to be "off balance." Live studios use high-quality wheels that are checked constantly for any problems. The old stories about people finding wheels that favor certain numbers do not apply to modern online casinos.
What's a "racetrack" or "voisins du zéro" bet?
These are just ways to bet on groups of numbers based on where they are sitting on the wheel. For example, "Voisins du zéro" covers the numbers near the zero. The house advantage is the same as if you placed the bets yourself; the racetrack just makes it quicker to do.
Why do live dealer studios cap their multipliers at 500x?
The 500x limit is there to keep the game stable and make sure the casino can always pay out the winners. These multipliers are funded by taking a slightly higher advantage on normal bets, so the casino has to balance how much they give away.
What's the deal with Lightning Roulette / Mega Roulette / XXXtreme?
These are special versions of the game with extra multipliers. They are more exciting because you can win a lot more money on a single number, but you will also lose more of your bets. They feel a bit more like a slot machine than traditional roulette.
Is roulette better than slots for RTP?
European roulette is usually better than most slot machines. However, American roulette is often worse. While slots can have very big swings in luck, roulette is a bit more steady, so it depends on what kind of game you enjoy playing.
Why do casinos let you play roulette if the house edge isn't in their favor?
The house advantage is always in the casino's favor. Every time you bet, the casino has a small edge that guarantees they will make a profit if enough people play. They do not need to cheat because the game is already designed to make them money over time.
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