Posted July 26, 2013 by John Baintree in News

The Psychology of the Slot Machine

Many casinos around the world embark upon a mission to have the best customer service, with casino workers constantly making sure the gambler is comfortable, has enough to drink, and is generally content as they part with their cash. However, it is not the bar staff on the casino floor, or even the table games operators who are the most important workers within gambling complexes. No, that role goes to the autonomous slot machine. There is a reason why slot machines are so heavily accounted for within casinos – they are the capitalists dream employee. The slot machine will sit their for all hours of the day, and will never complain as it consumes player’s money. In addition to this, the slot machine is the most intelligent thing in the casino, with it cleverly being disguised to look like the player even had a chance. That is not to say slot machines are unfair. They are fair; they do not discriminate against who they manipulate. ‘Manipulate’ may seem like a strong word to use in this case, but by the end of this article it will be totally justified. This article will demonstrate how there is no such thing as a ‘good slots player’, with anyone who decides to try their luck on the reels merely being a pawn in a game where the humble slot machine is in total control. Slot machines utilise subtle psychological techniques to influence player’s behaviours, with a large amount of academic research going into studying the interaction between slot machines and gamblers. The results are quick shocking and help to establish why casinos invest so heavily in the machines.

Playing slot machines is a notoriously addictive form of gambling, with it commonly being referred to as the ‘crack cocaine of gambling’. The simplicity of slots means that the machines are accessible by every type of gambler, from the newcomer to the seasoned veteran. You put money into the machine, you press a button and wait for the outcome. It is as easy as it sounds. However, a strange phenomenon that occurs within gamblers is the belief that they can influence games of chance, with the same notion being extended to slot machines. Players often forget the mechanical nature of slot machines and the fact they are programmed to follow set mathematical rules that determine how, and if, the machine pays out.

An interesting example of this is through how slot machines use the technique of the ‘near miss’. The ‘near miss’ is defined as being ‘a special kind of failure, one that comes close to being successful’ (Kassinove and Schare, 2001). In terms of slot machines, this is when, for example, in a game where it is required to match 3 symbols, the reels only display 2 matching symbols. This may be placed down to the machine being random, but that would be incorrect.


The occurrence of the ‘near miss’ is intentional and it has interesting effects upon the behaviour of the player. Studies have shown  that the inclusion of near misses as possible outcomes of slot machine leads players to wrongly attribute skill as a factor of the game (Billieux et al., 2012). For example, within actual games of skill, such as archery, a near miss would be almost hitting the bullseye of the target, which in turn makes hitting the bullseye seem plausible to the player, with this then spurring the archer on to fire more arrows. The same is apparent within slot machine games; the near miss outcome encourages the player to continue playing, with the belief that if they play enough, a win has to be around the corner. (Billieux et al., 2012)

However, a certain balance has to be struck between near misses, wins, and outright losses. If a machine is weighted too heavily to just produce losses and a minor amount of near misses, the player becomes discontent and will be reluctant to continue playing (Billieux et al., 2012). The game appears to be a fix; the player will never win. The same can also be said if the machine predominately produces near-misses as a result. Players become desensitised to the near miss, it holds no emotional value if overused and will equally discourage prolonged play (Billieux et al., 2012). It then becomes apparent, that if the correct balance of near miss occurrences is struck (around 30% of all spins), this encourages the gamer to keep playing, as they believe a win seems more realistic. This could not be further from the case; the machine pays out when certain conditions have been met, such as when it is sufficiently full of money. What the reels display has no baring on the odds that a win will soon come, and that should not be forgot. Whatever is being displayed on the reels is being displayed for a reason.

traiderThis is all well and good, but casinos and the gambling industry have evolved from the days of the ‘one armed bandit’ and the simple slot machine. Unfortunately, this has worsened the conditions for gamblers. With the advent of computer technology, video slots soon came to replace the more traditional variants, with these machines being even more unfavourable for the gambler. Video slots heavily use audio and visual cues to engage players, but this is not solely to add to the entertainment value of the game. It is to disorientate and distract. The most modern video slots allow gamers to bet on multiple lines, which is a vast change from the one pay line of classic slot machines. Yet, this does not increase the chance of the gamer to prosper and win money, it is merely another technique to distract the player, allowing the machine to make more profit. The research of Collins et al. has been particularly useful in displaying this, with the term ‘losses disguised as wins’ becoming established. Losses disguised as wins occur when the amount of money the slot machine returns in a win scenario, is actually less than the initial wagered amount. It may seem ridiculous and you may think you would spot this a mile off, but it is a frequent occurrence. Within losing situations, where no money is returned to the player, the slot machine will remain motionless, silent and unilluminated, which is typical behaviour for a losing spin (Dixon et al., 2010). On the other hand, on a winning spin, the slot machine will produce lots of audio and visual output to appeal to the senses of the player. Interestingly, the machine will behave in the same way when the amount ‘won’ is actually lower than the initial wager, which is obviously still a loss. The machine will bombard the player with audio and visual cues, just the same as it would for a full blown win (Dixon et al., 2010). This then helps to disguise the fact that the player is actually losing money. In addition to this, it also has a psychological impact upon the player, through the act of positive reinforcement. The player is being rewarded by music, lights and money for their actions, making the player believe that a desirable outcome has been achieved. It is even more shocking when it is revealed that the amount of losses disguised as wins occur more than regular wins. To make this point absolutely clear: the more lines a player bets on, the less likely it is they are going to achieve a profitable win, with a loss disguised as a win more likely to occur (Dixon et al., 2010).

As already shown, the visual elements of slot machines are extremely important and very influential upon the behaviour of the player. One of the more shocking findings comes when the level of anthropomorphism that is attributed to slot machines. Anthropomorphism simply when human traits and attributes are given to non-human objects. A clear example of machines being attributed human traits, is when drivers affectionately name their cars (remember Herbie the Volkswagen Beetle?), to make them seem more human. Believe it or not, it has been proven that if a slot machine is even vaguely anthropomorphous, then it influences the behaviour of the player (Kim and McGill, 2011). In an experiment where the features of a slot machine were redesigned to resemble a crude human face, by placing some seemingly innocuous metallic strips above the machine’s reels, so that the reel looked like a mouth and the strips acted as eyes and a nose, players’ risk perception was dramatically altered (Kim and McGill, 2011). People who were profiled and deemed to be ‘confident’ or ‘powerful’ individuals within society were more willing to play on the machine that seemed to have a face. It is said that due to their confident nature, and the subtle human attributes displayed by the machine, that they thought they could ‘influence’ the machine’s behaviour. This echoes the classic Vegas phrase ‘you make your own luck’. In this instance, you most certainly do not.

As you can see, the slot machine is not all fun and games. There is some clever psychology behind the machines, which heavily influence gamers into parting with more of their cash. It has been shown that with slot machines ‘less is more’. Multiple win lines on machines have been shown to stack the odds of winning even more unfavourably against the player, which is staggering as slot machines are already one of the most unfavourable games in the casino. It has always been said that the ‘smart money’ is played on blackjack or poker, games were skill plays some role in the outcome, where the player can have some form of control. In contrast to this, the ‘unsmart money’ goes on the slot machines. The player has no control of the game and is constantly at the mercy of the machine. It is advised that if you are playing the slots, then be very sensible. Always remember it is a game of chance, stacked heavily in  favour of the machine, and always be diligent; keep an eye on your money and make sure you’re not parting with more than you realise.





Kassinove J. and M. Schare (2001). ‘Effects of the “near miss” and the “big win” on persistence at slot machine gambling’, Psychology of Addictive Behaviours 15:2


Dixon, M. J., K. A. Harrigan, R. Sandhu, K. Collins and J. A. Fuselgang (2010). ‘Loses disguised as wins in modern multi-line video slot machines’, Addiction 105


Kim, S. and A. McGill (2011). ‘Gaming with Mr. Slot or gaming the slot machine? Power, anthropomorphism and risk perception’, Journal of Consumer Research 38:1


Billiex, J., M. Van der Linden, Y. Khazaal, D. Zullino and L. Clark (2011). ‘Trait gambling cognitions predict near-miss experiences in laboratory slot machine gambling’, British Journal of Psychology 103