History of Slot Machines History of Slot Machines
The history of slot machines, from the mechanical "Liberty Bell" in 1890s San Francisco through electromechanical slots, video slots, virtual reels, online casinos, Megaways, and mobile slots.
| English | History of Slot Machines |
|---|---|
| Classification | Basics & Betting Terms |
| Beginning | 1890s USA (Liberty Bell) |
| First electromechanical | 1960s (Bally "Money Honey") |
| First video slot | Mid-1970s (Fortune Coin) |
| Virtual reel patent | 1980s (Inge Telnaes) |
| Online casinos | Mid-1990s |
| Major turning points | Megaways (2016), mobile, bonus buy |
Overview
The slots spinning on your screen today started with machines that have a history of nearly 130 years. The history of slots can be summed up as a progression of mechanical → electromechanical → video → online → mobile. What matters is that with each stage, “how the result is decided” changed.
Trends by era
| Period | Event | Meaning |
|---|---|---|
| 1890s | Charles Fey builds the 3-reel machine “Liberty Bell” in San Francisco | The prototype of modern slots that pay out winnings automatically |
| 1900s-1910s | Machines that give fruit-flavored gum as prizes appear in areas where gambling is banned | Known as the origin of fruit symbols like cherries and lemons, and of the “BAR” symbol |
| 1960s | Bally releases the electromechanical slot “Money Honey” | Hoppers are introduced to pay out large amounts of coins automatically. The lever you pull matters less |
| Mid-1970s | Fortune Coin develops a video slot that shows the reels on a screen | A screen replaces the physical reels. IGT later acquires this company |
| 1980s | Inge Telnaes obtains a patent for the virtual reel method | Probabilities are assigned to far more “virtual stops” than the reel physically has → big jackpots become possible (virtual reels) |
| 1980s | Wide-area progressive jackpots linking multiple casinos appear, such as IGT’s MegaJackpots | The era of million-dollar jackpots |
| Mid-1990s | Online gambling licensing begins in places like Antigua and Barbuda, and the first online casino software appears | Slots move to the internet (Microgaming and others) |
| 2000s | Malta, Gibraltar, the Isle of Man and others set up regulatory frameworks for online gambling | Institutionalization of the online slot industry (Malta MGA) |
| Early 2010s | Smartphones spread and HTML5 games become widespread | Mobile slots go mainstream |
| 2016 | Big Time Gaming introduces Megaways | A structure where reel height changes on every spin spreads and becomes something like an industry standard |
| Late 2010s | Bonus buy, high-volatility and high-multiplier slots become popular | In 2020 the UK bans credit card payments for gambling, and in 2021 it introduces slot design rules such as a minimum spin time and a ban on autoplay (UKGC) |
| 2020s | Online casinos are legalized in several US states, along with crash games, social gaming and streaming culture | Regulated markets expand while responsible gambling rules tighten at the same time |
Changes in how results are decided
Mechanical
In early slots, real metal reels were stopped by springs and brakes, and that decided the result. With only about 10 to 20 stops per reel, the number of possible combinations was small and big jackpots were hard to create.
Electromechanical
The reels still physically spun, but electrical parts judged wins and paid out coins automatically. Payouts got faster and larger.
Computers and virtual reels
A computer’s random number generator (RNG) decides the result, and the physical reels (or the screen) only “display” that result. Virtual reels made it possible to give jackpot symbols very low probabilities, which allowed million-dollar jackpots. At the same time, the number of stops visible on screen no longer gave any hint of the odds.
Online slots
Online slots work on the same principle: a server’s RNG decides the result. With the limits of physical machines gone, structures that are impossible with physical reels appeared, such as tumbles, multipliers and Megaways.
Korea and slots
In Korea, casinos open to citizens are not allowed except Kangwon Land, and using unlicensed online casinos is also illegal. Casinos for foreigners and Kangwon Land operate offline slot machines. Online, you can get a feel for how slots work with free slot demos provided by the providers.