In the billion dollar casino industry, few gambling attractions have garnered more attention than slot machines. Despite their familiar appearance, these simple machines remain mysterious to the general public and the source of endless speculation about how they work. Unlike Texas Hold ’Em poker or blackjack, which are played by professional players and are based on mathematics, slot machines employ the laws of probability to entice and enthrall players while creating a profit for owners. The myths and misconceptions about slot machines are numerous, but a basic understanding of the principles behind them can help players maximize their chances for winning.
Although a relatively new addition to the casino floor, slot machines have a long history in American culture. The first machines were designed by a California gold miner in 1887, and the first official coin-operated machine was installed in a New York saloon in 1902. Since then, the popularity of slot machines has soared, fueled by their random number generators (RNGs), which produce unique combinations of symbols with each spin. The popularity of slots has also been fueled by their simplicity and low cost, making them ideal for use in a variety of settings.
The RNG is the heart of a slot machine and determines which symbols are drawn and which paylines are active. Most modern slot games have multiple paylines and a player can select how many lines they want to play. When a winning combination appears on a line, the machine will ring a bell and the player’s winnings are added to the total balance on the machine. In order to keep the gambling experience as immersive as possible, sound has always been a major component of slot design. In addition to the ringing bell, slot machines have a host of other sounds that are played during different events, such as a pay-out or a bonus round.
While previous research has examined the psychophysiological effects of music in isolation, it is likely that sound is congruently paired with images in slot machines, and that these stimuli reinforce each other. For example, in a multiline game, the winning jingle is accompanied by an animated visual representation of the winning combination, and the symbols responsible for the win are highlighted for the player with a coloured line connecting them. This perceptual onslaught may explain why slots are a popular form of entertainment and why players enjoy them more than other gambling games.
In the present study, participants played two sessions on a realistic multiline slot machine simulator. During one session, the game’s sounds were turned on, and wins and LDWs were accompanied by visual celebratory feedback and custom-created rolling and winning sounds. Skin conductance responses and heart rate decelerations were measured for both sessions. The results show that the sonic and visual stimuli associated with slot machines promote flow states, but that the context of play influences which aspects of the experience are endorsed. Dixon et al. (2019) reported that problem gamblers tend to endorse the darker aspects of slot enjoyment more than non-problem gamblers, indicating that the capturing of attention by slot machines plays an important role in their enjoyment of the game.
