Are There Different Types of Slot Machines?

For those who don’t play them, all slot machines look the same. They have reels that spin, stopping at random combinations of symbols, and they either pay or not. But there are thousands of slot machines available all over the world, online and in real life, and while many of them are similar, there are many differences between them.


The original slots built by Charles Fey in 1895 had three reels, five symbols, and a single win line. The spinning reels and the win lines counting combinations from left to right have remained mostly unchanged to this day. The standard number of reels has grown from three to five, and the number of win lines has also grown over the decades.

Most of today’s video slot machines have a standard 5×3 format. There are many, in turn, that have innovative formats, like more reels, more winning combinations, or relying on groups (clusters) of symbols. When looking at the format, we distinguish several slot machine types:

  • Three-reel slots with a limited number of symbols, and just a handful of win lines – these are often referred to as “fruit machines” because the reels often contain fruit symbols
  • Video slots or five-reel slots with (at least) five reels. Some of them have win lines in a traditional way, others use different methods to validate winning combinations.
  • Megaways slots usually have five or six reels but they don’t use win lines in the traditional sense of the word. Plus, they have symbols on their reels of variable sizes. In general, Megaways slots have between 7 symbols per reel on the screen simultaneously and are capable of forming tens of thousands of winning combinations. Some of them even have a horizontal reel to increase them.
  • Cluster slots can have any number of “reels”. Their symbols appear on the screen in a grid, and form winning combinations when touching horizontally or vertically, forming “clusters” of symbols. These usually disappear from the screen, allowing others to fall into their place, possibly triggering cascading wins.


Like all casino games, slot machines have a house edge built into them, representing the casino’s profits. The RTP or “Return to Player” represents the house edge – it shows how much money you can expect to lose when playing the game in the long run.

The industry average RTP for slot machines is around 95%. This means that for every $100 you play, you can expect to lose about $5. Of course, this only applies to playing the game for thousands, perhaps tens of thousands of spins. This doesn’t mean that you can’t walk away with big wins in your pocket – or without any cash, which, let’s face it, is more likely.


As opposed to the RTP, volatility or variability actually matters when you play slot machines, because it expresses how often the game pays out, and how much. 

  • A low-volatility slot machine will pay out frequently, but its payouts will be lower.
  • A high-volatility slot machine will pay less often, but the wins will generally be higher
  • A medium volatility slot machine is somewhere in between.

In general, if you are looking for a slot machine to play for fun, you’ll want to choose one with low volatility. The frequent wins, even if the amounts are low, ensure a frequent sense of accomplishment that you will enjoy more. If you have a large budget, you’re patient, and you’re looking for big wins, you should choose a high-volatility slot. 

Whichever you choose, in turn, make sure to play responsibly, and within your means. And most importantly, make sure you have fun while playing. After all, that’s what it’s all about, right?