The Origin and Evolution of Slot Machines: From the Liberty Bell to MegaWays

Origins: Why Are They Called “Slot Machines”?

The word “slot” in Slot Machine refers to the coin slot — because the earliest machines required inserting a coin to operate.

In Chinese, slot machines are called “laohuji” (literally “tiger machines”). There are two theories behind the name:

  1. Early machines had tiger illustrations on their casings
  2. They devour your money like a tiger

In Australia, slot machines are called Pokies (from Poker Machine), while in the UK they’re known as Fruit Machines (because early symbols were mostly fruits).

1887–1900: The Birth

Charles Fey and the “Liberty Bell”

In 1895, San Francisco mechanical engineer Charles Fey invented the world’s first true slot machine — the “Liberty Bell.”

Its design:

  • 3 mechanical reels
  • 5 symbols: horseshoes, diamonds, spades, hearts, and liberty bells
  • Automatic payouts: three liberty bells = top prize of 50 cents
  • One nickel to play

Earlier gambling machines existed (such as Sittman & Pitt’s 1887 poker machine), but none had automatic payouts. Fey’s invention changed everything.

1900–1960: The Fruit Machine Era

Why Do Slot Machines Have Fruit Symbols?

In the early 1900s, several U.S. states began banning gambling. To get around the law, manufacturers changed payouts from cash to chewing gum and candy, and replaced symbols with fruits (cherries, lemons, plums) — “Hit three cherries? Congratulations, you win cherry-flavored gum!”

The origin of the BAR symbol: it was actually the logo of a gum company called the Bell-Fruit Gum Company.

These fruit symbols are still used today — even though nobody trades slot wins for gum anymore.

Electrification (1960s)

In 1964, Bally released Money Honey — the first fully electromechanical slot machine. It could:

  • Automatically pay out up to 500 coins
  • Operate without a lever (though the lever was kept for tradition)
  • Offer more complex payout combinations

This marked the end of the mechanical era and the beginning of the electronic age.

1970–1990: The Video Revolution

The First Video Slot

In 1976, Fortune Coin Co. introduced the first video slot machine in Las Vegas — replacing physical reels with a 19-inch Sony display.

Players initially didn’t trust a machine without reels. It wasn’t until the machine was installed at the Las Vegas Hilton and approved by the Nevada Gaming Commission that it gradually gained acceptance.

The Introduction of RNG

In 1984, Inge Telnaes received a pivotal patent — applying virtual reel mapping to slot machines. Each physical stop position could map to multiple virtual stop positions, which meant:

  • Payout combinations could far exceed the limits of physical reels
  • The probability of each symbol could be precisely controlled
  • Larger progressive jackpots could be designed

This patent was acquired by IGT and fundamentally transformed slot machine math design.

Megabucks: The First Million-Dollar Jackpot

In 1986, IGT launched Megabucks — the first multi-casino linked progressive jackpot system. Slot machines across multiple casinos connected to a single prize pool, with jackpots quickly growing to millions of dollars.

In 1998, a 25-year-old software engineer in Las Vegas turned $100 into a $27,580,879 Megabucks jackpot — the largest single slot machine payout in history at the time.

1990–2010: The Online Revolution

The First Online Slots

In 1994, Microgaming released the world’s first online casino software.

In 1996, NetEnt (then called Net Entertainment) was founded, later becoming synonymous with online slot quality.

Early online slots were simply digital copies of physical machines — rough graphics, basic features. But the internet removed physical constraints, giving developers complete creative freedom.

Milestone Games

YearGameProviderInnovation
2003Mega MoolahMicrogamingThe king of online progressive jackpots
2006Gonzo’s QuestNetEntAvalanche mechanic
2012StarburstNetEntMinimalist design, the industry’s most popular slot

2010–Present: Mobile and the Innovation Explosion

Mobile First

Around 2012, HTML5 technology matured and slots began to be optimized for mobile. PG Soft pioneered portrait-first design, achieving massive success in the Asian market.

Today, over 70% of online slot traffic comes from mobile devices.

The MegaWays Revolution

In 2016, Big Time Gaming introduced the MegaWays mechanic. Each spin randomly varies the height of each reel, creating up to 117,649 win ways. The mechanic was licensed to virtually every major provider.

Crash Games

In 2019, Spribe released Aviator — not a traditional slot, but an entirely new type of “Crash Game.” A plane takes off with a rising multiplier, and players cash out before it crashes. The Provably Fair mechanism lets players verify every result.

This created an entirely new game category and influenced the whole industry.

Land-Based vs. Online: A Comparison

DimensionLand-Based SlotsOnline Slots
RTP88–93%94–97%
Game SelectionHundreds to thousands per casinoTens of thousands per platform
Minimum Bet$0.25–1.00$0.10–0.20
Development Cost$15,000–50,000 per machine$100,000–300,000 per game
Approval Timeline6–12 months2–6 months
Innovation SpeedSlow (hardware constraints)Fast (pure software)

The Future of Slots

  • VR/AR Slots: Meta and Apple Vision Pro are making immersive casino experiences possible
  • Skill Elements: Hybrid games that incorporate player interaction
  • AI Personalization: Real-time game recommendations based on player preferences
  • Blockchain-Native: Fully decentralized Provably Fair games
  • Social Features: Multiplayer interaction, live-streamed gambling, community features