Casino games fall into a few families: slots, live dealer games, blackjack, roulette, baccarat, crash games and other table games. Each has a house edge, the operator's built-in margin, which can also be expressed as return to player (RTP). Both are long-run averages, not predictions for a session. This page explains how the games work; it does not suggest playing them, and gambling faces legal restrictions in the Maldives.
On this page
- Single-zero roulette house edge
- 2.70%Source 4
- Double-zero roulette house edge
- 5.26% on most betsSource 4
- Baccarat banker / player bet edge
- 1.06% / 1.24% (eight decks)Source 5
- Blackjack 6-5 payout cost
- 1.39% worse for the player than 3-2Source 3
- RTP is measured over
- A very large number of gamesSource 8
This page compares the main families of casino game side by side: what each one is, and how much of a margin its rules hand the operator. It explains mechanics, not tactics, and it is not an invitation to play.
It stays at the level of the family. For what happens inside a single spin, our slots explainer goes deeper on one game type than this page does on all of them.
The main game families
Slots
Slots are software games. Each spin's result comes from a random number generator (RNG), and regulators such as Great Britain's Gambling Commission require that output to be acceptably random and unpredictable1. The reels on screen display a result produced by that software; they do not influence it.
Slots vary widely in layout and features. RTP, volatility and paylines are covered in depth on the slots page, and the slots database lists individual titles.
Live dealer games
In live casino, a presenter runs the game from a real table that players follow through a video stream2. The cards, wheel or dice are physical, and software turns the result into data. See live dealer games explained or browse live casino games.
Blackjack
The aim in blackjack is to beat the dealer: avoid going over 21, then either score higher than the dealer or have the dealer bust3.
Table rules move the house edge. Paying 6-5 on a blackjack instead of 3-2, for example, costs the player 1.39%3. That is why two blackjack tables can carry quite different margins. More in blackjack.
Roulette
A European-style wheel has 37 pockets (1 to 36 plus a single zero), giving a house edge of 2.70% on all bets. An American-style wheel adds a double zero, making 38 pockets and a house edge of 5.26% on most bets4. The extra pocket is the whole difference, because payouts stay the same.
On a single-zero wheel the 2.70% edge applies to all bets4. That is why no combination of roulette bets, however it is arranged, changes the long-run margin. See roulette.
Baccarat
Baccarat compares two hands, Player and Banker. Cards count at face value up to nine, tens and picture cards count as zero, and only the last digit of a total is kept5.
In an eight-deck game the house edge is 1.06% on the Banker bet, 1.24% on Player and 14.36% on a Tie. Banker wins pay 19 to 20, equivalent to a 5% commission5. More in baccarat.
Crash games
In a crash game, a multiplier starts at 1.00x and climbs until it stops at a random point. A stake that is cashed out before the crash is multiplied by the current value; one that is not is lost6. Rounds are short and repeat quickly. See crash games.
Other table games
Casino poker variants, dice games and other card formats are grouped under table games. Each follows the same principle: the rules and payouts determine the house edge.
House edge and RTP: one idea, two numbers
House edge is the share of stakes the operator expects to keep over the long run. Return to player is the share expected to be paid back. A game with a 4% house edge has a 96% RTP.
Great Britain's technical standards allow game information to show either the house edge or the RTP, as long as it is available before a customer gambles7. For games involving skill, such as blackjack, the RTP is calculated using a standard or published strategy7.
| Game and rule | House edge |
|---|---|
| Roulette, single zero (37 pockets) | 2.70% on all bets4 |
| Roulette, double zero (38 pockets) | 5.26% on most bets4 |
| Baccarat, Banker (eight decks) | 1.06%5 |
| Baccarat, Player (eight decks) | 1.24%5 |
| Baccarat, Tie (eight decks) | 14.36%5 |
| Blackjack paying 6-5 instead of 3-2 | 1.39% worse for the player3 |
The spread across that table is the point: the margin is a property of the rules in front of you, not of the game's name.
Both figures are averages over a very large number of games. The Gambling Commission notes that even 8,000 plays is too few for a fully random game to reach its target RTP; the real figure after that many plays would most likely be well above or below it8.
What the numbers cannot tell you
- What will happen in a session. RTP does not apply to a single player or session, and there is no pattern or cycle that makes a win "due"9.
- How bumpy the ride is. Volatility, the variability of outcomes, is a separate property from RTP10. Two games with the same RTP can behave very differently.
- Whether the game is fair. A published figure only means something if an independent body checks it. Great Britain's standards, for example, require random outcomes to be tested and forbid changing a game's rules, payouts or probabilities while it is available1. No such check can be assumed on an unregulated site.
- How fast money moves. The World Health Organization identifies casino games and high-speed online platforms among the gambling products associated with the greatest harm11. A small edge applied to many quick rounds still adds up.
Our guides on house edge and what RTP means go further.
Examples from the game database
Slots:
Video slot 
Video slot 
Video slot Live casino:
Live game show 
Live game show 
Live blackjack