Roulette is one of the most recognisable casino games, yet the maths behind it can seem confusing at first.
Terms like RTP (Return to Player) and house edge describe how the game is structured and why the potential payouts are set as they are. Understanding these concepts can help you see how roulette works and make sense of what the numbers really mean — without the jargon.
What Do Roulette Odds and RTP Mean?
In roulette, odds represent how likely an outcome may occur. The wheel contains numbered pockets, and your bet is placed on where you think the ball will land.
- European roulette has 37 pockets numbered 0 to 36.
- American roulette has 38 pockets, with an extra “double zero” (00).
If you bet on a single number in European roulette, the probability of that number winning is 1 in 37, or about 2.7%. The potential payout for this “straight-up” bet is 35 to 1, meaning a successful £1 bet would return £36 in total — £35 profit plus your £1 stake.
The difference between the true odds (36 to 1) and the possible payout (35 to 1) creates the casino’s built-in advantage, known as the house edge.
The Return to Player (RTP) rate is a theoretical figure showing the percentage of all money wagered that a game is expected to pay back to players over time. For European roulette, this is typically 97.3%, meaning the remaining 2.7% represents the house edge.
It’s important to remember that the RTP is calculated over thousands of spins and does not guarantee any winnings. Each spin is random, and the actual results in any session can vary greatly from this theoretical rate.
Before you play, it can be useful to check the information section within the game, where you’ll usually find details about the RTP, payout structure, and the version of roulette in use.
How Does House Edge Work in Roulette?
The house edge is what ensures the casino makes a consistent percentage of revenue over time. It’s not a fee or a hidden cost — it’s built into the payouts themselves.
- In European roulette, the house edge is 2.7%, based on 37 pockets, but payouts calculated as if there were 36.
- In American roulette, the extra “double zero” pocket increases the house edge to 5.26%, reducing the game’s RTP to around 94.74%.
Some French roulette tables feature rules such as La Partage or En Prison, which apply to even-money bets like red/black or odd/even. When the ball lands on zero, you either get half your stake back or it’s held for the next spin. This lowers the effective house edge on those specific bets to about 1.35%.
No betting system or pattern changes the house edge — it stays the same regardless of how you play. The maths behind the potential payouts is what determines it, not the choices players make.
What Are the Differences Between European and American Roulette Odds?
The main distinction lies in the layout of the wheel. Both versions offer the same payout for a single-number win — 35 to 1 — but the probability of that happening is slightly different.
- European roulette: 37 pockets (one zero) → 1 in 37 chance → 97.3% RTP → 2.7% house edge.
- American roulette: 38 pockets (zero and double zero) → 1 in 38 chance → 94.74% RTP → 5.26% house edge.
Because of this, European roulette is generally viewed as offering the possibility of a fairer return to players. However, the overall experience can also depend on your personal preferences and the features of the table you choose. Some online and land-based casinos may offer both, so it can be worth checking which version of roulette you’re playing by reading the game information before you start.
Why Do Roulette Odds Matter for Players?
Knowing the odds can help you understand how often different bets might win and what they pay if they do. Roulette offers two broad categories of bets:
- Inside bets – such as betting on one or a few numbers. These tend to win less often, but pay more.
- Outside bets – such as red/black or odd/even. These have the potential to win more frequently, but pay less.
For example:
- A single-number bet (inside bet) wins about once every 37 spins in European roulette, paying 35 to 1.
- A red or black bet (outside bet) wins on 18 of the 37 pockets, paying 1 to 1.
Both bet types are part of the same game and share the same house edge. The difference lies in how frequently they might win and how much they return if they do.
Roulette is a random game of chance, and each spin is independent of the last. There’s no strategy or pattern that can guarantee a win or influence where the ball lands. The best approach is to understand the bet types, decide how much you’re comfortable spending, and treat it as entertainment, rather than a way to make money.
Play Casino Games Online
At Clover Casino, you can explore real money casino games with clear information on every title. Roulette tables and other games include paytables, betting limits, and rules within the game, so you know how the bets and potential payouts work before you start.
Our games come from established providers and are tested to ensure fair outcomes. Whether you prefer classic tables or newer formats, the choice is straightforward and easy to navigate.
Please play for entertainment, set limits that work for you, and only wager what you can afford. When you understand the RTP, house edge, and how odds translate to possible payouts, you can make informed choices and enjoy roulette with confidence. Please play responsibly.
*All values (Bet Levels, Maximum Wins etc.) mentioned in relation to these games are subject to change at any time. Game features mentioned may not be available in some jurisdictions.
**The information provided in this blog is intended for educational purposes and should not be construed as betting advice or a guarantee of success. Always gamble responsibly.