In the world of gambling, slots remain a perennial favorite. Whether played with physical coins or virtual credits, these games are intriguing for their ability to harness the principles of probability to create a profit for players and owners. They combine engineering acumen, mathematical know-how, and psychological deceit in a form that is both familiar and mysterious.

The term “slot” derives from the early mechanical designs of electromechanical slot machines, which used a narrow slot to accept coin payments and spin the reels. As the machines evolved, they became a popular fixture in saloons. They became known as slots because of the coin slot, and they soon dominated the casino gaming industry.

Slots are designed to be addictive because of the way they trigger the reward centres in our brains. Variable rewards are powerful motivators, because the anticipation of receiving a reward (such as food, sex, money or information) is more rewarding than the actual experience. Variable reward systems work on animals too: they get us to keep seeking food, mates and information by triggering the release of dopamine in our brains.

In modern casinos, slots are controlled by random number generators (RNG), which produce a different outcome for each play. This is how we know that each spin is fair. Despite this, some myths persist about slots. For example, it is a common belief that a machine that hasn’t paid out for a while is “due” to hit. But the odds of each spin are independent of those of previous spins.