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Anatomy of a Slot

  • 1 Jan 2021
  • David
  • 0

The “slot machine” term derives from the slots on the machine for inserting and retrieving coins. Around the world they are also known as ‘fruit machines’, ‘one-armed bandits’, and pokies. You can find slot machines both in physical form typically in land based casinos or betting shops, or more frequently on online casinos. To someone who knows nothing about slot machines, they can be intimidating, bewildering and complicated and the majority of the time the games rules do little to help. Luckily for you, Return to Player is here to help and give new players at least a high level understanding to how a casino slot machine works…

The article is written in a question and answer point of view as it reflects many questions we receive from site visitors. For the purposes of this article I’ve picked Quickspin’s ‘The Three Muskateers’ to illustrate the discussion points, mainly because it’s awesome and it’s not too heavy on slot features.

  • So, to kick off, why would anyone play a slot?

To get the elephant out of the room, a slot machine is a gambling machine. The purpose of the game is to win money. There are other pulls introduced in the last few year such as achievements, social interaction, and gamifaction, but ultimately players play slot games to primarily win money and secondary be entertained.

  • Okay, so how do I win?

Well there is no guaranteed way to win. Slot games like most casino games are fixed odds games. This means that you can mathematically model the odds of winning from a game, which typically takes the form in a value called the RTP or ‘Return to Player [ED: See what we did with the name? ;)].

  • So what does the RTP tell me?

Three Musketeers - Game Info

A slot game’s RTP tells the player the theoretical average percentage return to the player over a period of time. So an RTP of 96% means that over a period of time, if you bet/stake £100 you can expect to receive £96 back in win. The inverse of this is called the house edge which is the theoretical average percentage that the casino or house will make from your stake.

  • That sucks, so why would I play if I know the game is expected to the pay me less?

RTP Simple Example

It’s important to note the word AVERAGE in the above. There are other statistical aspects to would apply to this RTP value such as volatility and deviation that are outside of the scope of this article but that value is purely an average. I’ve highlighted the simple points in the chart below

This chart shows 20 bets on a slot game and the corresponding win. In the example the player has bet £200 (20*10) and won £190 (5+20+10+60+80+10+5). Now that we take the theory away from it, the actual player return is 95% of their stake (£190) and the house edge, which is now the actual casino hold, from this player is £10 (5%).

When the theoretical RTP is calculated the game is simulated millions, even billions, of times which should highlight how simplistic this example is.

  • Okay… I understand your RTP theory, but I’m still losing money right?

Not quite. If you appreciate that based on the RTP there is a long term advantage to the casino, then the real reason for playing a slot is that players are hoping to offset the long term advantage against a short term big win. Again going back to the chart above, let’s just say that for any run of 20 bets on a slot game, you get these wins irrespective of whoever plays. Imagine if a player started their play at round 15 and quit at round 18? That would mean that for their total stake over these 3 rounds they’ve spent £30 (£10*3), and they’ve won £90 (£0 + £80 + £10). That means that the player has increased their money by 200% and walked away from the machine.

  • Great! So I just need to understand the win frequency and start and quit when the machine is paying?

Absolutely not. The above example is overly simplified, and there is no way to obtain an unfair advantage or put the odds in your favour. These sorts of calculations are purely theoretical and will not represent experience you have in reality. A slot machine is based on randomness and any belief that you can play the odds in your favour is known as ‘Gambler’s Fallacy’. So play a slot machine with the view that you may win, you may lose, you may stay the same. The one thing you can be sure of based on theory is that the longer you play in one session, on average the more likely, the casino will be keeping more of your money.

  • Okay okay, so that said, I understand the risk and I want to play. So how do I win?

A generic slot game in its basic form has reels, rows, symbols and win lines.

Traditionally in the land based/physical games, there would be an actual reel that has the symbols overlaid on the outside; When you spin a slot machine, these reels spin and stop presenting a section of the symbols in the game window. The purpose is to hope that the reels stop in the game window in a way that matches a number of the same symbols along a win line. As the games have moved to online there is obviously no physical reel but the software still replicates the same functionality digitally.

  • I understand that. But talk me through the screen though and what I’m looking at?

The below picture shows the main game with some of my annotations highlighting the keys parts [ED: the little red numbers 🙂 ].

Three Musketeers - UI

The BALANCE (1) field a.k.a casino WALLET indicates the amount of money you have or own. You can deposit more or withdraw from this, as you see fit.

The BET (2) field is the amount of money you are willing to stake per WIN LINE. And then the LINES field allows you to select the number of lines that will be played on that bet which basically means the number of opportunities for matches you’ll have in the game window.

The TOTAL BET (4) is usually the BET*LINES which shows you how much you are betting or staking in total on this one game or one SPIN in the case of a slot. This means that the more lines you enable, the more you will be betting. In this example of Three Musketeers, you have a “20 + feature bet” lines (3) so that means 20 x 0.04 (2) which equals €0.80 and then “+ Feature Bet” which is a side bet we won’t delve into here but essentially all you need to know is that it is 1/4 of your bet, so a further €0.20 on top bringing your total bet to €1.00 (4).

The first step for most slot players would be to load the ‘HELP’ or the ‘PAYTABLE’ (5). This will show you the symbol hierarchy and the win lines:

Three Musketeers - Paylines

You can see how much the game will pay if you match the symbols along the line. If you match the higher value symbols along the win lines you’ll receive more win for your bet. Likewise the more win lines you have active, the greater likelihood that you’ll end up with ‘matches’ after each spin.

A good example is below of a winning line.

Three Musketeers - Payline Example

  • I see references to ‘scatters’ and bonuses? What are these?

Slot designers cottoned on pretty early that playing the base game (i.e. simple matching of symbols along the pay lines) can be quite boring and monotonous. Plus if you want to make a game more volatile (again not in scope here, but let’s say you want to ensure the game pays little amounts frequently and a big amount infrequently) you can only do this by changing the paytable, changing the symbols on the reels, and or increasing /decreasing the number of symbols. Thus slot developers introduced additional features to make the game more engaging.

As you flip through the PAYTABLE or possibly as you first load the game you’ll find information on the bonus games or scatter symbols. A bonus game is effectively a sub game within the slot whereby the functionality is different from that of the base game. Typically they are activated by the scatter symbols which are in effect special symbols that carry additional functions beyond a win ratio.

  • And what can I expect from a bonus game?

One of the more common and simple bonus games is called ‘freespins’ in which the player wins a fixed amount of spins where they aren’t charged the stake for each spin, but they still get to keep the prizes. It’s as simple as that.

Other bonus games can become quite complex in that it can be a picking bonus game in which you are asked to pick an unknown item on the screen that presents a particular prize, or a layered game on top that looks like something else but when you boil it down to basics it’s a picking mechanic. An accumulator game where you are playing the same slot but now the reels have certain new symbols in there where you need this to appear a fixed number of times to satisfy a condition. Some casino games can even have skill based elements to their bonus rounds where you play a small mini game to unlock prizes.

  • Sweet, so skills games, the better I am the more I win right?

Unfortunately not, as I said again all casino games are fixed odds based on luck. So whilst skill mechanics may be used to obtain more prize win, it has to be within boundaries that again fall within the theoretical RTP as above.

  • But there is skill in blackjack though? Isn’t there?

In a game like Blackjack there is no skill element but there is strategic play. Strategic play comes from numerous people modelling the basic premise of a game (such as Blackjack) and determining a play strategy that limits the house edge. You can find many sites that propose Blackjack strategies but the important thing to note is that the strategy never removes the house edge, it only minimises it over long-term play. Such example could be: ‘always stand 16 when the house is dealt a 10 card first.’. Something like that.

  • Okay well I saw this game called Castle Builder where you build a castle and get paid at the end. How does that work?

Games like Castle Builder (see the review here by the way) have progressive win elements or single player, seeded jackpots. What that means is that as you play the game a section of the RTP (say 5%), or in other words, part of the accumulated stake, is placed into a ‘pot’ within the game. As you play the game there is a trigger for unlocking this win (plus potentially more) back to you. Again, jackpot functionality is beyond the scope of this article but the main point of jackpot games is that there is an additional win available beyond the standard game that can be triggered for some lucky players.

  • Right I’m ready to enter an online casino. Where do I start?

That’s is up to you. In today’s online casino sector, the player has a lot of choice in both casino operators and casino games. There are two ways to approach it. Find a casino you are comfortable with, and then chose the games you like from their portfolio. Other option is find a game or types of games you like and then find a decent operator that offers those games.

Hopefully, if you’re reading this, then you already know that Return to Player, is your best source to find out about the hottest new games, so head to the Reviews section. If you have any questions about any game head over to the forums.

Image ©2009-2016 FeiGiap available from Deviant Art

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