Slot machines are defined by the spinning reels on the front of the machine, but that wasn’t always the casino. Before 1900, any vending machine was considered a slot machine. That makes sense when you think about it, because all vending machines have a slot for coins. Usage of the phrase to refer to gambling machines with spinning reels became prevalent during the 20th century.
This page covers the history of slot machines—the gambling game, not vending machines in general. We cover everything from Charles Fey and the Liberty Bell up to the present day, with its menagerie of complex games like 243 ways.
The Liberty Bell: Inventor, Charles Fey
The first machine a modern gambling audience would recognize as a slot machine was the Liberty Bell, which was invented by Charles Fey in 1895. Like most basic slots throughout history, the Liberty Bell consisted of three spinning reels. Symbols included diamonds, spades, hearts, and the Liberty Bell. If you hit three Liberty Bells, you won the jackpot—50 cents.
Fey went on to invent a draw poker machine, a precursor of sorts to our modern video poker games, in 1901. His business model was simple enough with both machines. Saloon owners would rent the machines in exchange for 50% of the profits.
Charles Fey was just a car mechanic working out of a small shop, and demand for the Liberty Bell was enough to keep him busy all the time. He refused to sell the rights to his machine to larger gambling supply manufacturers. It didn’t take long for these companies to create their own version of his machine.
These early slot machine games were entirely mechanical in nature. Metal hoops made up the reels. A lever set the reels in motion. The symbols were painted onto the metal reels, and the jackpots were paid out in coins into a hopper. You could only win a jackpot if you lined up three of the same symbol in a row across the center of the front of the machine.
In 1909, the government outlawed slot machines for money. Clever slot machine owners responded. They began offering prizes–fruit-flavored candies and chewing gum. In fact, one of the most common symbols on modern slot machines is the bar symbol, which was originally the symbol for winning sticks of chewing gum.
Slot machines remained mechanical in nature until 1964, when Bally Manufacturing (the maker of Quick Hits) invented the first electronic slot machine. This game was called Money Honey. Instead of using springs, the game used electronic parts. They also added sounds and lights. Most importantly, they offered players the chance to wager multiple coins per spin.
In 1975, Walt Fraley invented a game called “The Fortune Coin”, which featured a video with virtual reels. Three years later, William Redd and International Game Technology bought the Fortune Coin Company. IGT remains the largest and most popular manufacturer of slot machine games today.
In 1980, IGT made the most significant change to slot machine games in history. They increased the number of paylines. The new computer-powered machines with multiple paylines made it possible to offer unheard of jackpots, along with a higher hit frequency than ever before.
Video slots became incredible popular. Before the 1980s, slot machines might take up 20% of a casino’s floorspace, and this was mostly a concession to the wives of the serious gamblers. A decade later, most casinos generated 70% or more of their revenue from electronic gaming machines.
One of the most significant innovations since the 1980s is the progressive jackpot. Games with progressive jackpots use a tiny percentage of each wager to build a massive, constantly-growing jackpot. These were initially single machines, but with the rise in computer technology, casinos and gaming manufacturers started linking multiple machines’ jackpots. These shared jackpots could grow even faster because multiple players were contributing to the jackpot at the same time. The most famous of these games is the MegaJackpots wide area progressive, which regularly offers jackpots in excess of $10 million.
Bonus games and features also became popular on machines throughout the last few decades. These bonuses might be as simple as a single symbol which acts as a multiplier to a small jackpot. They might be as complicated as an entire video game that’s triggered when certain symbols or combinations of symbols hit the screen. You’ll have a hard time finding a modern slot machine game that doesn’t feature some kind of bonus symbol or game.
Scatter symbols are also a relatively new development. These are symbols which trigger payouts regardless of where on the screen they land. They don’t have to be on a payline. Features like scatter symbols and bonus games are effective in attracting more players who are willing to wager higher stakes.
One of the most recent developments in the slot machine industry is the growing popularity of 243 ways games. These games dispense with the paylines entirely. Every possible payline from left to right is, in effect, activated, so on any given spin, there are 243 different ways to win. When symbols appear on the screen from left to right, no matter where on the reel stop, they trigger a winner.
Increases in Time on Machine
Casinos and slot machine manufacturers have determined scientifically that the best predictor of how profitable a slots game will be is a statistic called “time on machine”. They’ve increased players’ average times on machine by offering more frequent (but smaller) wins. Since a player is often wagering on multiple paylines, it’s not unusual for a player to win something on almost every spin. Even though that win is smaller than the amount wagered, the player receives the same stimulus-response, and eventually a state of flow is achieved.
One thing is certain about the future of slot machines. Manufacturers will continue to innovate. The popularity of slot machines is greater than ever before, and casinos are going to capitalize on that by making sure that gamblers have something new to look forward to.