Hard to imagine as it is, today’s slick, mobile-friendly online slot has its roots in the head of a San Francisco car mechanic as a clunky, spring-loaded, cast iron-clad box of reels, levers, and notches. The evolution of this mechanical marvel from its early beginnings over 100 years ago to the modern reel-based mobile games of today is a fascinating one. And with AI, AR, VR, and smart tech all becoming ever more present in our lives, who knows how slots will evolve next.
The Birth of the Mechanical Slot Machine
The very first mechanical slot machine was called the Liberty Bell. It was invented in the mid 1890s by a San Francisco car mechanic by the name of Charles Fey. The design was fairly simple: the machine had just three reels, each one featuring five symbols: horseshoe, diamond, spade, heart, and a Liberty Bell.
The original slot wasn’t just admired for its visual design. It was the first piece of machinery to introduce an automatic payout mechanism. A lever attached to a spring was used to start the reels spinning. Inside, a complicated setup of levers and notches was used to read the final reel positions and pay out coins.
The Era of Fruit Machines
Cash payouts were banned in many US states in the 1900s, which threatened to wipe out Fey’s ingenious invention and its many offshoots by that point. In order to survive, manufacturers had to get creative, so they adapted the machines to pay out chewing gum and sweets instead of coins.
Slots were redesigned to feature cherries, lemons, and melons, which corresponded to the flavours of the awarded gum. The famous Bar symbol that still features in many of today’s slots was originally the logo of the Bell Fruit Gum Company that produced the chewing gum.
These fruity slot creations were so popular that they crossed the pond and became a familiar sight in UK pubs and seaside arcades. Modern versions of these early slots are still affectionately termed ‘fruit machines’.
When Electronics Replaced Mechanical Parts
As technology advanced, the use of electronics began to pop up everywhere, and slots got their fair share of the innovation. The first fully electromechanical slot was Money Honey, which was launched by Bally Manufacturing in 1963. This slot was revolutionary, and not just for its bottomless hopper and automated attendant-free payouts of up to 500 coins (before which casino staff had to manually check and pay out large amounts).
While still largely mechanical in nature, the addition of electronics injected new life into an old favourite. Slots like Money Honey could now feature flashing lights, automated electronic sounds, and even the ability to handle multi-coin betting. It also represented the first threat to the mechanical lever, the tactile trigger that set the reels in motion and was responsible for the slot nickname ‘one-armed bandit’. Despite their replacement with electronic buttons, many slot levers were retained for nostalgia.
The Video Slot Revolution
As it turns out, video didn’t just kill the radio star, but also the mechanical reel. Technology marches on, as it does, and soon enough slots were treated to their next evolution: the transition from physical reels to screens. The first true video slot was developed by Fortune Coin Co. in 1976. Simply named Fortune Coin, it replaced dimly lit mechanical reels with a modified 19 inch Sony Trinitron TV receiver – in full colour.
No longer constrained by physical reels, developers were suddenly granted creative freedom. Slots began to feature more detailed graphics and gameplay that boasted multiple paylines. New bonus round mechanics also started to appear. In the mid 90s, developers like WMS Industries introduced feature action that shifted gameplay to an entirely new screen design.
The Internet Changes Everything
The invention of the internet in the mid 90s marked another major milestone in the slots evolutionary timeline. Video slot development led to the creation of games built on Java and Flash that could easily be launched within a browser. Suddenly, the slot spinning experience was no longer confined exclusively to land-based casinos. Anyone with an internet connection could now spin the reels, from anywhere, at any time.
Today, players can choose from numerous modern online platforms, log in to a UK regulated online casino like PlayOJO and get immediate access to thousands of slot titles via their browser.
This transition to virtual slots gameplay naturally raised concerns about game fairness. People still had more trust in mechanical reels than the newer video and virtual slots, whose inner workings were inaccessible and potentially maliciously programmable. This led to the development of the digital Random Number Generator (RNG), a complex algorithm designed to replicate unpredictability. RNGs replaced physical reel-stopping mechanisms and introduced a more mathematical system of ensuring fairness.
Slots Move to Smartphones
The launch of the first iPhone in mid 2007 followed by the first Android phone in 2008 marked the dawn of the smartphone era. This introduced us to a new user interface experience: the capacitive touchscreen. However, smartphones didn’t support the games’ original Flash and Java software, which meant initial mobile slots were clunky and awkward, with some simply not working on mobile at all.
That all changed with the industry wide rollout of HTML5 in 2011. This technology meant games could be developed to be playable across desktop, tablet, and mobile, without the need to download apps. Players could explore industry leading slots like the NetEnt Touch series, including Gonzo’s Quest, directly from their mobile web browser.
The smartphone UX led to a shift in slot UI design. Gameplay moved from mouse clicks to touchscreen taps, responsive design ensured optimal display regardless of specific mobile device, and portrait orientation was added to cater for how users hold their phones.
The launch of 4G network coverage in late 2012 led to dramatically increased mobile internet speeds, which meant much faster performance of slots on smartphones when out and about.
What Modern Slot Games Look Like
Since more of the market than ever before could now access slots on any device at any time from anywhere, an explosion in both quantity and quality followed. Advances in digital engineering means modern slots now look more like high-end video games.
Today’s slots feature innovative reel setups and designs, such as cascades or avalanches, which see winning symbols disappear and new ones falling into their place, potentially triggering additional wins.
Paylines are no longer fixed, with mechanics such as Megaways using smart algorithms to dynamically change the number and size of symbols on every spin, leading to hundreds of thousands of ways to win.
Audiovisual upgrades have resulted in HD 3D animations, complex, orchestra quality soundtracks and effects, and a massive variety of themes.
Recognising that 95% of the UK population owns a smartphone, today’s slot developers largely take a mobile-first approach to game design, while operators follow suit by supporting both mobile browser-based play and downloadable apps.
What Might Come Next?
Based on current trends in artificial intelligence, augmented and virtual reality, and device development, the next steps in slots evolution could be interesting.
We could see AI interfaces that adapt visual designs, audio experiences, and game suggestions based on player preferences.
AR and VR technology could lead to the creation of virtual reality casinos, where players can navigate a digital lobby and interact with 3D slot machines.
Developers could even pre-empt the next smart tech trend by creating stripped down slots that can be played on smartwatches and other wearable devices.
No-one can predict the future, but if the past century of slots development has taught us anything, it’s to expect the unexpected.
