Understand How Online Slots Work

From one perspective, free spins no deposit no wager slots are the easiest game there is. There is no strategy or skill involved, all the player has to do is choose the size of their bet and press spin while the slot does the rest. If winning symbols land on paylines, you have scored a win. But on the flip side, slots are complicated computerised games that have many systems working together to give you the game that you know.

In this article, we talk about some of those things that are working under the hood of slot games. 


The most common question asked by the players is about how the outcomes of your spins are decided in slot games. This comes down to an essential computer component in every slot game – the RNG. It stands for random-number-generator and it does exactly as expected. The RNG creates series of long, random numbers (10 digit numbers and longer) in rapid succession (several numbers within a second). The outcomes of your spins are based on these numbers. 

  • The RNG is a randomising device in slot games and it guarantees a fair game that is down to luck and chance.

  • Land-based slot machines use a True RNG (TRNG) which is a computer chip secured inside of the machine.

  • Online slots use a Pseudo RNG (PRNG) which is a multi-faceted computer program.

  • It is unknown what influences the RNG performance – slot developers do their best to hide the algorithms used in slot games from the public. If this information leaked, slots could be manipulated by hackers. 

Volatility/Variance and RTP 

The RNG works together with a few other variables to provide you the games as they are. 

  • Volatility/Variance is a measurement of risk within a slot. A low-variance game pays out in smaller wins but does so more frequently. These are reliable games that can keep you playing for longer. A high-variance game can have series of low-paying or zero-return spins, followed by random bigger wins. These slots offer a bigger winning potential along with a higher risk of losing.

  • The RTP stands for return-to-player and is a generally accepted guide to how a game will perform. It measures how much of the total lifetime bets placed on the slot are paid out as wins. An RTP percentage of 98% means that in theory, the slot will pay out 98% of all the money it has ever taken in while the casino will keep 2% as the house edge. RTP is measured over a large number of spins, for example, 1 million. The higher the RTP, the bigger the chance to win. 

Progressive jackpots 

Progressive jackpots are some of the most popular slots today. At first look, these games will have lower RTP percentages and might seem like poorly-paying games. That is because the main attraction is the progressive jackpot which is made up of all the players’ bets and can grow into colossal prizes. For example, Mega Moolah slot (Microgaming) winners have pocketed such prizes as £5 million, £10 million and €18 million!


There are many other progressive jackpot slots that players love and play every day. A progressive jackpot game offers the biggest winning potential ever in the history of slots.

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