How Video Slot Developers Use Maths Models in Their Games

Online casinos are hugely popular in the UK and the games that get the most play are video slots. Their popularity can be explained by the simplicity of the gameplay, the exciting and engaging themes, and the sophisticated maths models that drive the payouts, just like with real money pokies. Developers use two important levers to dicatate how often and how much game will pay out during a session: Return to Player (RTP) and Variance. Here we look at both and show how they work in modern video slots.

Return to Player (RTP)

RTP is a simple value that shows how much a game will pay out in prizes as a percentage of all the money wagered. If a game has a 95% RTP then it will, on average, pay out £95 for every £100 wagered. Of course, this value will change from session to session, with some players experiencing a higher than 95% RTP, and others a lower than 95% RTP. The money held back by the game is referred to as the house edge. Most video slots have a house edge of around 4% (96% RTP), whilst some table games, like Blackjack for example, have a much smaller house edge of 1% or 2%.

Clued-up slots players will check the RTP of a game before they start playing and search out those with higher RTPs. Games with the highest RTP include 1429 Unchartered Seas by Thunderkick (98.5% RTP) and Bloodsuckers by NetEnt (98%).

Variance or Volatility

The second key feature of a slot that determines the frequency and size of payouts is Variance. This refers to the variation from the average RTP a player will experience during a session. Slots are categorised as low variance, medium variance or high variance. Low variance games pay out regularly and normally in quite small prize values. This is because over time the payout pattern does not vary much from the average RTP. High variance games are at the other end of the scale. The variation from the average RTP here will be huge, and typically players may experience long periods with little or no payout (low RTP) before the situation is tuned on its head and in just a few spins the slot will pay out huge winnings at a high RTP.

The volatile nature of high variance games makes them a risky proposition for a gambler – the enticement of a big payout is always tempting, yet the player knows that the game may hold back and burn through the balance without returning a single penny.

In recent years high variance games have become increasingly popular as a new breed of slots developers have arrived on the scene. Studios like Australia’s Big Time Gaming, Nolimit City and Relax Gaming are specialists in building high variance slots with clever themes and in-built features that make for blistering win sequences when, after a long spell of dry spins, the game eventually does produce one of its big win moments.

Perhaps the most famous example of this is Big Time Gaming’s Bonanza Megaways™ slot, a video game that showcased the developer’s new expanding reels format back in 2016. Here, after every spin the number of symbols on each reel randomly changes, up to a maximum of 7. This creates an element of surprise as more symbols mean more possible paylines. Combine this with special multiplier symbols which also randomly add value to any given payout, and free spins which are randomly dished out to lucky punters, and you have a highly sophisticated, engaging and entertaining slot. Many consider it to be one of the best executions of a high variance slot maths model ever created, though of course there are many other examples.

The Megaways™ game format proved so popular that now in 2020 there are hundreds more games that have adopted the game engine with great success and it is to be carried over into offline slots on the floors of Vegas casinos.

The success or otherwise of a gambling slot is dependent on many factors, but RTP and variance are two of the most important. Next time you play one be sure to check these out before you start as they are a great indicator of the kind of experience you will have, and the level of payouts you can expect. You can read more about video slots, RTP and variance, as well as reviews of the latest games at fan site and gambling guide, TheSlotBuzz.com.