How do slots work?

There are thousands of slots available to play online, developed, designed and delivered by numerous Casino Games providers. Games are designed to suit different tastes aesthetically, and what one person might love, another might not be so fond of. The two common factors behind all casino slot games are: the way that they are programmed to determine winners – by using a computer program called a Random Number Generator (RNG) and how often they are set to pay out (Slot Volatility)

The Random Number Generator (RNG)

The RNG is a microchip that continuously generates random numbers (thousands per second) and each number generated has no connection to the previous number generated. There are different types of RNG’s and the ones used by casinos are called pseudo random number generators. These RNG’s do not need any external input to function, they only need a ‘seed number’ and an algorithm and new seed numbers are produced every millisecond.

On a slot machine the RNG would assign a value to each slot on the reel. For example, let’s assume there are 16 symbols per reel and you are playing a 5-reel slot. The RNG would then ‘spit out’ a value of 1-16 for each of the 5 reels which would display 5 symbols. If the result of the 5 symbols makes a winning combination then you would be paid according to the pay table chart.

How do we know that RNG’s are fair?

Well, honestly it’s impossible for the average person to tell whether a RNG is fair or not – saying this, all reputable casinos will have their software tested by third party companies. Most casino game providers will also have their games independently tested and iTech Labs in Australia is a popular choice for this.

What is extremely important to remember is that RNG’s are always set with an advantage back in favour of the casino. The longer you play, the casino will beat you due to the mechanics of the game. It’s not to say that you can’t have a lucky streak or run where you ‘beat’ the slot.

Slot Volatility

It would be quite boring if all slots payed out at the same rate hence a ‘volatility level’ is build into modern day slots. Casinos don’t usually publicise the volatility levels of games (we really don’t know why as there is nothing to lose in doing so) but essentially slots are either considered to be high or low volatile.

High Volatility signifies that a slot will not pay out frequently however the likelihood is that when it does pay out, wins should be bigger.

Dead or Alive
‘Dead or Alive’ A highly volatile slot.

Low Volatility means that a should should pay out more frequently however wins would be be on the lower side.7

The Phantom's Curse
‘The Phantom’s Curse’ an example of a Low Volatile slot

With this information in hand, we would recommend playing High volatility slots to people who have a larger bankroll and who can afford to go a longer time without a win. If you are a person that just wants to play slots to pass some time and get the most out of the gameplay and features of the slot, then we would recommend playing Low volatility slots.

Typically, online casinos will hand out Free Spins on games which are LESS volatile to give the player the experience of more frequent wins. There is nothing more frustrating for a player than receiving free spins and not winning anything on them.


Now there are two things you need to look to do.. go and grab a casino bonus and then have a read of our Slot Strategy guide to get the most out of your gameplay.