Slot innovation and how they are made

If you are reading this, you want to learn about slot innovation and how slots are made, what goes into developing these games and how to get the playing experience that’s best for you.

Slot Machine Basics

The world of slot machines can be confusing and complicated, but this piece hopes to guide you through so that by the end, you’ll feel like an expert.

The Rise of the Slot Machine

The growth of slot machines is a worldwide phenomenon and in many locations, they actually surpass the popularity of all table games combined. Why is this? Reasons include:

• Slots are easy to play
• The minimum bets of slots are affordable
• Slots are fun and entertaining to play for all types of player
• A small wager can win big!

Slot machines have been around since the late 1800s, originating from the tinkerings of a San Francisco mechanic, and have gone through various phases since. Such as:

• They’ve been used as business builders on shop counters, dispensing chewing gum instead of cash
• They’ve been entertainment for spouses of gamblers in casinos while their partners play at the tables
• They’ve been mechanical, clockwork devices

Now, they are high-tech enigmas containing animation, video, surround sound and special effects

House Edge?

Even though slot machines generally pay less than other casino games, tens of millions of people play online slots every single day.

John Grochowski published an article about payout percentages in the United States and how to maximise your slot payouts. Grochowski found that the house edges 13-to-16 percent at the 1-cent denomination, 10-to-12 percent on 5-cent games, 7-to-10 percent on quarter games and 5-to-8 percent on dollar machines.

Here in the UK, that means a penny slot player might be spotting the house £16 for every £100 they play.

Why Play Slots?

So, why play slots? On a percentage basis, slots (and online slots) can’t compare to table games, but there are many reasons players choose them:
Slots are easy to play.

There’s pretty much no learning curve in playing a slot machine. You choose your stake, push a button and watch the reels spin, simple. Also, unlike some table games, there are no particular strategies to learn.
Slots have low minimum wagers.

Most online slots have extremely low wager opportunities. Simply put, slots can be inexpensive entertainment. The speed of these wagers is also enticing as it’s possible make several hundred bets per hour or more, with bonus events and features bringing in even faster gameplay with certain slots.

Slot offer huge jackpot opportunities.

Big money is possible on the slots. It’s possible to win thousands (and sometimes even millions!) on certain games with one extremely lucky spin. The largest jackpot in history, $39.7 million, came on a $3 bet. Of course, such large jackpots are extraordinarily rare events, but any dedicated slot player occasionally collects winnings hundreds of times the size of the bet.

Slots are fun!

The advent of online slots has set game designers’ imaginations free. Slotmakers now spend a massive amount of time and money developing interactive, entertaining slot games that give the player a good time, even when not winning. The themes and stories behind these slots now are as important as anything – the player now takes an active role. Now, the emphasis is on games that are fun as well as having a chance to win.

Slot Machine Invention and History

Slot machines are such a common sight in modern casinos and so widely played online that it’s easy to think this has always been so. But, slots have evolved tremendously over the last 120 years.
Did you know…?

• The first three-reel slot machine had a maximum jackpot of half an US dollar
• Many early slot machines did not pay off in cash
• Computerised slots with random number generators enabled more volatility and bigger payoffs

The biggest impact on the modern slot machine has certainly been technological advancement. Now, the only real limit on game design is the designer’s imagination. However, slot machines were invented long before computers…

Charles Fey and the Liberty Bell

Coin-operated gaming devices existed before Charles Fey invented the Liberty Bell in 1895, but it’s with the Liberty Bell that leads to modern slots. Fey’s invention had three spinning reels, a handle on the side and a slot for coins.

The game’s features included:

• Five different symbols on the reels – horseshoes, diamonds, spades, hearts and a Liberty Bell
• A single payline across the middle of the display
• The top payoff which comes up for lining up three Liberty Bells
• A total jackpot of…wait for it…half a dollar!

A simple, elegant and long-lasting design is what made the Liberty Bell so innovative.

Three reel slot games still exist in casinos today.

Herbert Mills

Herbert Mills, a manufacturer from Chicago, introduced a three-reel slot machine called the Operator Bell in 1907. Mills was a leader in coin-operated devices, including:

• A movie-viewing machine called the Autosteroscope
• An ice cream-making vending machine
• Machines for dispensing Coca Cola

Mills’ machines were the most widespread early slot machines and it was actually Mills who put fruit symbols on slot games for the first time. Hence, in the UK, why slot machines are sometimes referred to as “fruit machines”.

Trade Simulators

Slot machines that paid money were illegal in the US until casino gambling was legalised in 1931. Of course, this didn’t mean such machines didn’t exist, but monetary payoffs often had to be out of sight…

Some slot machines were placed on merchants’ counters to attract customers and help business

Certain slots paid off in merchandise (e.g. cigarettes, chewing gum) rather than money

The trademark logo of Bell Fruit Gum was a black rectangular bar, and that inspired the famous ‘bar’ symbol still used in modern slots today

Rise of Bally

The company Lion Manufacturing was founded in Chicago in 1932 and one of its early successes was a pinball game known as BallyHoo. Now Bally Technologies, the company is part of Scientific Games today. After the legalisation of gambling, Bally placed itself to challenge Mills for the slot machine leadership. The Bally Baby was a tiny countertop model that Bally created to dispense award cards that could be exchanged for chewing gum.
Among Bally’s innovations were:

• The Bally Bell, the first slot machine to accept more than one coin denominations
• The popular Hi Boy upright slot in the 1940s, which established Bally as a major provider of slots games
• Electromechanical slots, introduced in the 1960s
The coin hopper, introduced along with electromechanical slots, enabled much bigger payoffs that were paid out without having to stop play

International Game Technology

In the 1970s Si Redd, a Bally engineer, invented video poker. Redd took the game on his own and founded a company called Sircoma. Today, this company is International Game Technology and has gone on to supplant Bally as the world’s largest slotmaker, merging with GTECH in 2014. IGT’s innovations have included:
• Computerised slots with virtual reels and random number generators
• Wide-area progressive games, linking machines in different casinos for multi-million dollar prizes
• Popularisation of the bonus wheel, famously used in the TV game show ‘Wheel of Fortune’

Worldwide Flavour

Slots have their roots in the United States and American slotmakers remain among the worldwide leaders. However, there is now a global flavour in the world of slots. As well as the American slotmakers like WMS Gaming and Scientific Games, there are Austrian-based Novomatic, Japan’s Konami Gaming and Aruze Gaming, with branches in the US, Australia, South Africa and Chinese city Macau.

Video Breakthrough

Most slot machines in use today are on video screens rather than using mechanical reels. The early slots, available in the 1980s, attempted to mimic the three-reel experience and weren’t all successful. To attract players, video slots needed to offer something different.

In 1994, the Game Maker was introduced by Bally and included slot, video poker and video blackjack games. This was the first video slot that achieved a degree of real popularity. Bonusing slots from Aristocrat and WMS followed and the popularity of video took off.

Slot innovation : important Advances

Slot machines are more reliant on technology than other casino games. Advances in technology have changed the types of games that manufacturers can now offer.

The coin hopper enabled bigger payoffs at machines and ticket printers later replaced coin hoppers

The virtual reels enable games with bigger odds and jackpots
Bonus wheels and video bonus plays give players something extra to hold their interest

Arguably, Charles Fey’s Liberty Bell machines are the most important invention in slot machine history, but in the 120-plus years since there have been many innovations and inventions that have gone into developing the games played today.

The Coin Hopper

So, why was the Coin Hopper so important?

Earlier slot machines used coin tubes that were too rigid and coins had to be stacked in them

The Coin Hopper enabled slots to circulate coins for payouts from a larger pool

A larger pool of coins meant payouts could be bigger, eventually circulating more than 1,000 coins

Nicolaus and Breitenstein’s invention enabled gamemakers to design games with larger and more frequent payoffs.

The Virtual Reel

In 1984, Inge Telnaes developed the method for mapping symbols and spaces, or ‘stops’, from a physical reel onto a virtual reel. This was a game changer for many reasons:

Big jackpots require big odds against winning so increasing odds require increasing the number of possible combinations of symbols and spaces
Before the virtual reel, the main solution was to increase the size of the reel
Telanes’ virtual reel meant game designers could make reels behave as if they had any number of symbols and spaces

More stops meant more flexibility for game designers to give players games with high volatility, low volatility, big jackpots, frequent jackpots and everything in between

Without the virtual reel, big money games wouldn’t have been possible, nor even slots that today would be described as having ‘moderate’ jackpots.

Linked Progressive Jackpots

Slots with progressive jackpots add a portion of each wager to the jackpot amount until a player wins it. After, the jackpot resets to the starting amount and builds up again.

Linked progressives electronically link multiple games so that a bet on any of the machines raises the jackpot. Then there is the wide-area progressive which is where you’ll find the biggest jackpots, linking to neighbouring machines and those across different casinos.

The IGT Megabucks slot was the first wide-area progressive slot game which linked machines throughout the states of Nevada (including casinos in Las Vegas). It was on Megabucks that the world record jackpot of $39 million was won in 2003.

Multi-Tiered Progressives

Multi-tiered jackpots are common throughout any walk-through casino and this format first debuted in Australia before moving to the US in the late 1990s. Multi-tiered progressives share some key features:

The emphasis is on small, attainable jackpots that keep the player involved with frequent wins

• Some multi-tiered progressives have even smaller rollover values for more frequent hits, while some have higher rollovers for less frequent but bigger jackpots
• Most multi-tiered progressives have large jackpot displays stretching across several machines so players can see when the bank is full and progressives are being awarded often

IGT, WMS, Bally and other manufacturers have all brought out their own multi-level progressives and they are now available with as few as two levels, or alternatively 10 or more.

The Bill Validator

Simply, bill validators scan bar-coded payout tickets as well as currency and offer increasing flexibility to meet modern casino demands. Developers of cash handling solutions have devised validators that are programmable and adaptable to different sized notes that read currencies from all around the world.

Ticket Printers

Today, most payoffs come in bar-coded tickets that can be used to buy credits for a different machine or can be exchanged for cash. Some players miss the sights and sounds of coins pouring out of slot machines, but printing bar-coded tickets has obvious security advantages for both the player and casino, so are the mainstay of most modern establishments because of this.

Multi-Game Machines

Installing multiple games on the same machine allows players to choose what they want to play without moving around. Again, Bally is the innovator of this with their 1994 Game Maker.

Slot Bonus Wheels

Anchor Gaming’s Wheel of Gold in 1995 was a sensation. The original wheel was affixed on a tower atop slant-top slot machines. People would stop to watch and see how many bonus credits a player would win. IGT’s Wheel of Fortune followed and today many manufacturers use bonus wheels as extras on their slot games.

Multi-Line Video Slots with Bonus Play

The Pacific Rim was the proving ground for what has become the hottest gaming trend of the last 15 years.

WMS Gaming had the first mega-success in the US in 1997 with Reel ‘Em In, with just five paylines (three across the five video lines), a ‘v’ and a chevron. Players could touch the screen to choose an angler to reel in fish for bonus credits. Creative, entertaining forms of bonus play are now key to modern slot popularity.

Today, video slots dominate casino floors with multi-tiered jackpots, mystery bonuses and community style play. Real slot innovation.

Next chapter of our Slot Compendium: How video slots work