Online roulette

How online roulette works

A roulette wheel has numbered pockets in red and black plus one or two green zero pockets. You place your chips on the table, the dealer or the random number generator spins the wheel and the ball stops in one of the pockets. All bets covering that number win; the rest lose.

Online, roulette comes in two forms. RNG roulette is a computer game where a random number generator decides the result and you set the pace yourself. Roulette with a real dealer is instead streamed from a studio, and everyone at the table plays the same round. The maths is the same in both cases – it is the rules, not the format, that determine the house edge.

The bets are divided into two groups. Inside bets are placed on single numbers or small groups of numbers and give high payouts. Outside bets cover larger groups, such as red/black or a dozen, and win more often but pay less.

Roulette variants: European, French and American

There are three classic variants, and the difference between them comes down to the number of zeros and special rules for even-money bets.

European roulette has 37 pockets and a single zero. The house edge is 1/37, which works out at about 2.7%. If you have the choice between European and American roulette, it is always the European version that gives the best odds.

French roulette has the same wheel but an extra rule for even-money bets (red/black, odd/even, 1–18/19–36). If the zero comes up, La Partage gives you back half your stake, and under French rules you can choose between half the stake or En Prison. This halves the house edge on those bets to 1.35%.

American roulette has both 0 and 00, so 38 pockets, but the same payouts as the European version. The extra zero raises the house edge to 5.26%. Worst of all is the five-number bet on 0, 00, 1, 2 and 3, which pays 6:1 and has a house edge of 7.89%.

Roulette bets, odds and probability

The table shows the payout for each bet in European roulette and how likely it is to win in a single round. The probability is calculated as the number of covered numbers divided by 37.

A payout of 35:1 means you win 35 times your stake and also keep the original stake. A straight-up win with 10 kr therefore gives 350 kr in winnings and 360 kr back in total.

Notice the pattern. If the wheel had only 36 pockets, every bet would be exactly fair: a straight-up number would win once in 36 and pay 35:1. It is the zero that creates the house edge, and it is the same size for all bets in European roulette. Whether you bet on a number or on red, the expected loss is 2.7% of your stake.

Roulette strategy: what the maths says

There are many roulette systems, but none of them changes the house edge. Every spin is independent of the previous ones, and every bet has the same negative expected value. A system can change how your wins and losses are spread over time, never how large they are on average.

Expected value in kronor

If you bet 100 kr on a straight-up number, you win 3,500 kr once in 37 and lose 100 kr the other 36 times. Over 37 spins that comes to 3,500 − 3,600 = −100 kr, or about −2.70 kr per spin. If you instead bet 100 kr on red, you win 100 kr 18 times and lose 100 kr 19 times, which also gives −100 kr over 37 spins.

Over a longer session, the difference between the variants becomes clear. At 100 kr per spin for 100 spins, you wager 10,000 kr. The expected loss is then roughly:

• 270 kr in European roulette (2.7%)
• 135 kr on even-money bets with La Partage (1.35%)
• 526 kr in American roulette (5.26%)

The Martingale and other progression systems

The Martingale involves doubling your stake on an even-money bet after every loss, so that the first win recovers everything and gives a small profit. It often works over short periods, and that is precisely what makes the system treacherous.

The chance of losing a bet on red in European roulette is 19/37, because the zero also counts as a loss. The probability of losing seven times in a row is under 1%, but over 100 spins the risk is about 36% that such a streak happens at some point. If you start at 10 kr, after seven losses you have staked 10 + 20 + 40 + 80 + 160 + 320 + 640 = 1,270 kr, and your next stake has to be 1,280 kr – to win 10 kr. The table maximum or your budget calls a halt long before the system “gets the chance” to work.

The same applies to d’Alembert, Fibonacci and reverse systems such as Paroli. They control the size of your stakes but do not change the probabilities. The expected loss is always the house edge multiplied by what you wager.

What actually makes a difference

There are three things you can control yourself. Choose European or French roulette over American. Choose La Partage tables if you play even-money bets. And decide your stake size and number of spins based on a budget you can afford to lose, because the expected cost grows with every krona you wager.

Statistics on previous numbers, which many tables display, do not affect the next spin. If red has come up six times in a row, the chance of black is still 18/37.

Common mistakes at the roulette table

Most mistakes in roulette are not about placing the wrong chips, but about how you think about the game. Here are the most common ones:

• Choosing American roulette. With two zeros you pay almost twice as much in house edge for exactly the same payouts.
• Believing a number is “due”. The wheel has no memory of previous spins. A number that has not come up for a long time has the same chance as all the others.
• Chasing losses. Raising your stakes to win back what you have lost is the fastest route to an empty budget, whether it is called the Martingale or not.
• Covering almost the whole table. Bets on many numbers at once give more winning rounds, but the house edge applies to every krona you stake. You win more often, but lose just as much per krona staked on average.
• Playing roulette to clear a bonus. Table games often contribute little or nothing to the wagering requirement, so read the terms first.

A simple trick is to decide the number of spins before you start. With a fixed stake and a fixed number of rounds, you know roughly what the game will cost in advance, and you avoid making decisions in the middle of a winning or losing streak.

Roulette with multipliers

Several game studios have developed variants where certain numbers get multipliers. One example is Evolution’s Lightning Roulette, where between one and five lucky numbers get multipliers of 50x–500x in each round. The price for that is that a straight-up number normally pays 29:1 instead of 35:1; if you hit a lucky number, the payout can be up to 499:1.

According to the game sheet, the optimal return to player is 97.3%, meaning the same 2.7% house edge as classic European roulette. Straight-up bets do, however, have a lower return, so check the information panel before you play. Pragmatic Play Live has similar games such as Mega Roulette, PowerUP Roulette and Gates of Olympus Roulette. We go through which studios and tables are available at Swedish operators on our page about live dealer casino games.

Play roulette for free in demo mode

If the casino offers RNG roulette in demo mode, you can try the game for free with play money. It is a good way to learn the table layout and the different bet types without it costing anything. You can also use demo mode to see how quickly a budget runs out with different stake sizes.

Just remember that demo mode tells you nothing about how the next real round will end. The outcomes are just as random, and the maths in the tables above applies in exactly the same way with real money. If you want to compare roulette with other games, such as slots and blackjack, you will find all our guides among our online casino games.

Best roulette casinos with a Swedish licence

All the casinos below are licensed by Spelinspektionen (the Swedish Gambling Authority) and state that they have live casino from Evolution, the studio behind Lightning Roulette, among other games. We have not played at the casinos ourselves; we compare them based on the casinos’ own terms and information. You can always check an operator in Spelinspektionen’s licence register.

LeoVegas has Evolution’s live casino and states over 3,000 games. Bear in mind that roulette will not help you clear the welcome bonus: according to the terms, European Roulette contributes 0%, as do Evolution’s table games.

Unibet names Evolution as its live provider and has a casino app for both iOS and Android. While wagering the bonus, the maximum stake is 25 kr per game or spin according to the terms.

Casumo has Evolution for live casino and lists a long line of other providers. Card deposits are made with debit cards, as credit cards have not been accepted since 1 May 2026.

ComeOn names Evolution as its live provider and states that withdrawals are processed within 24 hours. You will find more operators with a Swedish licence in our comparison of online casinos.

Play roulette responsibly

Roulette is fast, especially the RNG variants, and it is easy to wager more than you intended. Set a deposit limit you are comfortable with; at Swedish casinos it is mandatory, and an increase takes effect after 72 hours at the earliest. Take a break if you notice you want to chase losses.

If you need to exclude yourself, you can do so immediately for 24 hours at the casino, or at all licensed operators via Spelpaus.se, the national self-exclusion register. Stödlinjen, the national gambling helpline, can be reached on 020-819 100. We have gathered more advice and tools on our page about responsible gambling.