How an online slot decides a result
When you press spin, the game asks a random number generator for numbers and maps them to positions on each reel. The spinning animation is a display of a result that already exists. Nothing you do between spins (stopping, waiting, changing stake) changes the odds of the next one. How slots work, in full.
What it costs
Every slot publishes a return to player. If it is 96%, the game returns £96 of every £100 staked across millions of spins and keeps £4: the house edge. That is the honest price of playing. At £1 a spin and 600 spins an hour, a 96% game costs £24 an hour on average. Try your own numbers.
How bumpy it is
Volatility is how that cost is spread out. Low volatility pays small amounts often; high volatility goes quiet for long stretches and pays rarely but bigger. Same average either way. See it simulated.
The features
Modern slots are built around features: free spins, Megaways, cascading reels, hold and win, multipliers and many more. We explain 28 of them here. None of them changes the RTP; they change where in the game the money is paid.
The rules in Great Britain
- £5 maximum stake per spin, £2 if you are 18 to 24.
- At least 2.5 seconds per spin; no autoplay, turbo or slam stops.
- Age and identity checked before you play, even demos.
- No credit cards. No bonus buy. Bonus wagering capped at 10×.
Every rule, dated and sourced.
Where to play
Only at a site licensed by the Gambling Commission. How to check any site in two minutes.
Questions people ask
Are online slots legal in the UK?
Yes, in Great Britain, at sites licensed by the Gambling Commission, for adults aged 18 and over. Northern Ireland has its own gambling law.
Are online slots rigged?
Licensed online slots use tested random number generators and pay back their published RTP over the long run. They are not rigged, but they are designed to keep a share of stakes, so on average you lose.
What is the best online slot?
There is no best slot for winning: every game has a house edge. Higher RTP means a lower average cost; volatility decides how bumpy the ride is. Pick on cost and features, and set a limit.
How much can I bet on online slots?
In Great Britain the maximum is £5 per spin if you are 25 or over, and £2 per spin if you are 18 to 24.