There’s a lot of different online slot games around, from classic five reelers to modern video slots with hundreds of paylines. While some have a distinct theme that gives them their look and feel, it’s the underlying mechanism at play that determines whether or not you win.

A random number generator (RNG) selects a set of numbers that correspond to a particular outcome, as soon as the reels stop spinning. This is how developers know when you’ve won, but you won’t, since you don’t know what the next spin will be before it happens.

The RNG also ensures that you can’t predict a pattern of winning or losing. That’s important, because if you were to find one, the casino wouldn’t have much control over how much it paid out, and it would take longer to build up a large prize pool.

Another way of controlling the amount that you win is by using multipliers or scatters, which can make your wins more substantial. A x2 multiplier, for instance, doubles any payout you receive if it forms part of a winning combination.

You can also find progressive jackpots, which are shared across a network of thousands of players and can pay out huge prizes. You’ll usually need to play at max bet to qualify for these, so it’s worth checking the pay table to see if you can make the most of them. Finally, some online slot games have extra features such as cascading reels, which can boost your chances of landing a winning spin by replacing symbols with new ones.