Slot Machine Variance: An introduction

If you’re at all experienced with playing slot machines, the term ‘variance’ is one that you may be used to seeing. The variance of a slot machine determines how the game plays, how likely you are to hit wins, and – when the wins do hit – what size they’re typically going to be.

In this post, we’re going to look at what variance is, how it affects the game play, and what the three main types of variance are, within slot machines.

Slot Machine Variance – What is It?

The variance of a slot machine means how risky the game is to play, in the short-term. It’s also known as the volatility of a game – and it dictates how frequently a slot machine pays wins, and what size these wins typically are.

There are three main types of variance within slots; high variance, low variance, and – sometimes – medium variance. Below, we’re going to take a look at these different variance levels, and how they affect your game play.

Volatility and RTP are separate measures. Games can share the same theoretical RTP while paying out very differently, as this short video shows with two invented models.

Read the video transcript

Questioner: Why can two games with the same RTP feel completely different?

Explainer: Because the average return and the spread of payouts are different things. RTP describes the theoretical long-run return relative to stakes. Volatility describes how widely payouts vary. Let’s compare two invented models, not real games.

Questioner: Can you show me the difference?

Explainer: Each model costs one rand per play, with a hundred equally likely outcomes. In model A, forty-eight outcomes pay two rand each. The other fifty-two pay nothing. In model B, four outcomes pay twenty-four rand each. The other ninety-six pay nothing. Both average ninety-six cents paid out per one-rand stake: ninety-six percent RTP. Model B pays much less often, in larger amounts. Its payouts vary much more.

Questioner: So will a hundred plays return ninety-six rand?

Explainer: No. These squares show possible outcomes, not a schedule of results. The same outcome can happen again, and your actual return can be far above or below the average. Higher volatility does not automatically mean higher RTP. Neither model owes you a recovery. You can lose your entire balance. The useful distinction is average return versus the size of the swings, not safe versus profitable.

High Variance Slots

High variance slots are defined by how their payouts are spread, not by their RTP. RTP and volatility measure different properties: a high variance game can have the same theoretical RTP as a low variance one. Check the RTP published for the exact game version you play.

As a general rule of thumb, high variance slots don’t pay out too often – but when they do, they are capable of paying a pretty substantial amount of money.

For example, when playing a high variance slot, you may find yourself enduring quite long periods of ‘not much happening’. You may get a few small wins here and there, but big wins (100X your stake or higher) are rare.

That is how the game’s maths spreads its payouts, not the game saving up a win. A random, independent game does not store up a win to make up for previous losses.

High variance slots also tend to have a significantly different pay table compared to low or medium variance games.

High variance games will typically award a fairly good pay-out for matching 5-of-a-kind combos of even the worst symbols in the game – and compare this to low or medium variance games, and you’ll see where the potential lies.

High variance slots are also different in the way that they tend to have a lot of their RTP within the bonus rounds, rather than the base game. What this means, is that you’re far more likely to see the big wins distributed within the bonus round, rather than within the base game.

That’s not to say big wins can’t be found in the base game – but it will typically be a lot less frequently than during the bonus.

If you want to play high variance slots (and there are some reasons why you may want to), then the biggest piece of advice to remember is to set a budget you can afford to lose before playing, and stop when it is gone. A bigger balance does not protect you from losing it.

It’s not uncommon to go long periods without a lot happening, and you should be prepared for this to happen.

Low Variance Slots

Low variance slots – as you can probably imagine – are the polar opposite to high variance machines. Low variance describes smaller, more frequent payouts. It does not mean a higher RTP: the RTP is set separately, so check the figure published for the exact game version.

Low variance games tend to be preferred by more casual slot players; those who are looking for extended play time and excitement, as opposed to the chance of hitting big wins.

Unlike high variance machines, low variance slots tend to pay out very frequently. Of course, the wins they pay out are generally worth substantially less than the high variance machines, and you’re unlikely to find many wins paying over 100X your stake.

The pay-outs associated with symbols also tend to pay out substantially less than high variance games.

For example, many low variance games offer just 1X or 1.5X your stake for a 5-of-a-kind combination of the lower-value symbols – and this allows you to see just how different they are.

Low variance games tend to feel more action-packed, with smaller wins landing more often. How often a bonus feature triggers depends on the individual game, and smaller swings do not stop a balance running down: dry spells still happen and every spin can lose.

Medium Variance Slots

There are, contrary to what some people say, medium variance slots – and while it’s true that most slot machines can be categorised as being either low or high variance, games can be medium variance too.

Medium variance slots are relatively straightforward; they’re a game where you’ll see semi-frequent wins and semi-frequent big wins.

Naturally, the win-potential will be lower than that of high variance slots, but make no mistake; medium variance games are more than capable of paying out decent wins.

As with the other levels, a medium variance rating tells you nothing about the RTP on its own, so check the game’s published RTP.

How To Figure Out a Game’s Variance

Unfortunately, few game developers – at the time of writing – publicise whether their games are high or low variance. Some do – including Wazdan and Pragmatic Play – but generally speaking, they don’t.

So, if you’re trying to figure out the variance of slots, there are a few things to look for in your quest.

Firstly, check the game’s information or help screen and the developer’s own details for the exact game version. Where a volatility rating is published, that is the most reliable guide. The RTP is usually shown there too, but it will not tell you the variance: games with the same RTP can distribute prizes very differently.

The other method of determining a slot’s variance is to look at the pay table. The pay table is in no way a sure-fire way of determining the precise volatility, but it can be used to give you an idea. Generally, the lower the pays, the lower the variance – and the higher the pays, the higher the variance.

Alternatively, the final way of determining the variance of a slot game is to play it yourself. Playing will give you a feel for the game, and allow you to see the variance level first-hand.

However, a session of any realistic length can land far above or below the average, so what you see is not a reliable measure of the game’s variance. Playing longer does not change that, and only adds more stakes at risk.

Demo play (using play money) is the safer way to get a taste of how a game plays, without staking your own money.

Is a Slot Ever Due a Win?

A long losing run on a high variance slot can make a win feel overdue. It isn’t: when outcomes are independent and the game rules are unchanged, earlier losses do not make the next result more favourable. Games with a disclosed feature such as a bonus meter can carry a changing game state, so read that game’s rules. This one-minute video explains the difference.

Read the video transcript

Questioner: Ten losing spins. Surely the next one is more likely to win?

Explainer: Not when the outcomes are independent and the game rules are unchanged. The earlier losses do not make the next result more favourable. Think of a fair six-sided die: even after ten rolls without a six, the next roll still has a one-in-six chance of a six.

Questioner: So the game isn’t saving up a win?

Explainer: Exactly. Our die is an analogy, not a slot’s actual odds. Moving past results off the screen leaves the same six possibilities for the next roll. A losing streak is history, not a progress bar towards a win. Playing longer adds more stakes at risk; it does not erase what you have already lost.

Questioner: What about a bonus meter?

Explainer: A disclosed feature can have a changing game state. Read its rules; that is different from a win becoming due just because you lost. For independent base-game outcomes, a past losing run alone changes nothing. Do not chase losses or raise stakes to force a comeback. Stop at your planned limit.

Variance: A Conclusion

One of the things it’s important to be aware of is that’s it’s generally not advised to pay too much attention to variance. Sure, the variance of a game does shape how it plays, but it describes the spread of possible results, not what will happen in your session. Whatever the variance, decide your limit before you start and do not chase losses.

The most important thing is that you find a slot you’re happy to play. Take the time to browse through the various slot machines available, and don’t rush into playing one.

Remember, you can always try out a slot in demo play (using play money) before committing to using your own, hard-earned cash, and this is an excellent way of testing out various games.