Slot Machines Meaning & Explained

Slot Machines Meaning & Explained

Slots machines are the most popular of all casino games. There is hardly a casino in the world, land-based or online, that doesn’t offer a lot of slot games to players. While slots require no skill to play, there is still a lot that one should know before spinning the reels, whether you’re looking to make some cash at the end of the day or just playing for fun. We created this comprehensive guide featuring slot machines meaning, types, and winning strategies.

How Slots Work

Playing slots is the easiest thing you can do in a casino; pick a slot and spin, then wait a few seconds to see if similar symbols align, and you win. This is how slots work from the eyes of most players. However, there’s more to slots than just spinning the reels and waiting for winning combinations.

The game begins with you spinning the reels, whether you are online or in a land-based casino. If you’re playing in an online casino, the entire game is virtual, and there are no handles but buttons that need to be tapped. The reels have different symbols depending on the slot’s theme. When you place your bet and spin the reels, the symbols fall randomly to form a combination.

How do slots work
At the end of a spin, the symbols can form a winning combination

You win a slot game when the symbols line up according to the game’s payline. Regardless of where you’re playing, the outcome of every slot spin is controlled by a technology known as Random Number Generator. This innovation, also called RNG, ensures that the results of all spins occur by chance and cannot be rigged by the casino or you. In essence, all you have to do is bet, spin, and wait for luck to smile on you.

Gambling Slot Machine Meaning & Definition

Often, newbies ask the question, “what are slot machine gambling games?” A gambling slot machine is a betting game; you place a bet and spinning the reels to reveal a winning combination of symbols. Slot machines may be mechanical or electrical.

Traditional gambling slot machines are operated with coins and a lever. You insert a coin and pull the lever or handle to trigger a spin.

Instead of physically inserting a coin and pulling a lever, online slot machines are operated by depositing cash on a gambling site, choosing a bet, and pressing the spin button.

Slots Explained in English

It’s possible you’re here and still wondering: what is a slot machine? In simple English, a slot machine is a betting game often played in physical or online casinos. We have broken down the meaning of the game in simple points below:

  • A typical slot machine is divided into grids or columns referred to as reels.
  • The reels carry different symbols, and they spin when you are playing the game.
  • Different slots have different numbers of reels. The most common are three-reel slots and five-reel slots.
  • To spin the reel on a slot, you must place a bet and then press the spin button. The reels will spin for a while and then stop to reveal a lineup of symbols.
  • Every slot has a paytable or payline showing the lineup of symbols that make a win.
  • If the reels stop with a lineup of symbols that match what you have on the payline, then you win.

History & Origins of Slots

Charles August Fey is credited for building the world’s first-ever mechanical slot machine called “The Card Bell.” He first designed the device in 1898 with painted symbols, then made another version with different themes called the Liberty Bell. Charles figured he could make money by renting the “Bells” out to bars and taverns, and he did. The slots were so famed that some years later, Herbert Mills came up with the first slot machine to use the fruit symbols. It was called the Operator Bell, and just like Charles’ bells, it also grew famous. Players could operate the slots and win coins or food and drinks as prizes.

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The popularity of mechanical slot games continued until 1963, when the first electronic slot game was launched. In 1976, the Las Vegas Hilton unveiled the first video slot. Within years, slot games have spread across casinos all over the globe, with different versions and themes being developed. However, the creation of the first online casino by Microgaming Software was the turning point for the outpour of many different innovations in modern slot machine games. Nowadays, we have hundreds and thousands of slot games available to you in virtual casinos worldwide.

Gambling Machine Laws

Nevada was the earliest to legalize gambling in the 1930s. By the 1940s, when the Flamingo Hotel in Las Vegas unveiled its first slot machine, the city became the seat of all the fun. By the 1980s, many states in the US had legalized gambling. Nowadays, states also have laws regarding online casinos, and bettors can enjoy slot machine games at their fingertips in casinos where slot games are legal.


The chances of the slot machine stopping on a particular lineup or combination of winning symbols are called odds. Odds represent how likely you will win in a slot machine game. The odds of the earliest slots were straightforward to calculate since there were fewer reels and symbols, leading to fewer winning combinations or paylines.

While earlier slots could have three reels with ten symbols, a single reel in a modern slot can have up to 30 symbols.

In recent times, modern slots have more reels and symbols with multiple paylines and odds that are programmed into the slot. Since the slot machine is designed to spew random results using Random Number Generators, the odds of winning remain the same, and neither the casino nor you can alter them.


Slot machines in casinos have different themes. The theme of a slot is one of the most entertaining features of the game, especially for modern slots. Themes are reflected in the kinds of symbols on the reels, the sounds, lighting, and the background story of the slot machine.

Earlier slot machines had painted symbols and were mostly just different fruits. But nowadays, slots, especially video slots, are themed based on movies, celebrities, fictional stories, and TV shows. Many gamblers choose a slot to play based on their theme. Some slots are even themed after board games like monopoly.

Basic Terminology & Features of Slot Machines

We have discussed the history and origin of slots and provided you with the basics of slot machines explained. But before you go ahead and spin the reels, here are some more things you should be familiar with.

About Slot Machine Reels

When it comes to how slot machines work, the reel is at the center of it all. This is why the term “spinning the reel” is often used to mean playing a slot game. The reel is the feature of the slot machine game that holds the symbols which show you when you win. They are the horizontal columns that spin as you play. Most slots have three reels, but there are some with five. Nowadays, you may even find six reel slots, but those are still relatively new and very rare.


As mentioned earlier, modern slot machines work with the aid of computers. Almost all of the modern slot features and functions are computerized, from the images on the screen to videos and the random results of spins. However, the Random Number Generator is the most popular aspect of slot machine computerization that is often discussed. Read on to find out what this technology means and how it works on a slot machine.

Slot Random Number Generators

Random Number Generators are critical to the functionality of a slot machine. They determine when the reels stop spinning and what combination of symbols appear. RNGs ensure that the slot machine generates a random outcome at every spin.

What Is Payout Percentage

Another important slot terminology is the Payout Percentage or Return to Player (RTP). This represents the amount a slot machine pays you when you win a bet. Here is an example. Let’s assume a slot machine has a payout percentage of 95%. If you bet $100 on that machine and win, theoretically, you get a payout of $96.

Paytable & Paylines

The winning combinations for a slot machine are usually displayed on the paytable or payline. This is where you find out which lineup of pictures or symbols will give you a win. This will also determine the payout you get when you win. Slots machines usually have multiple paylines, allowing you to choose the number of lines you want to bet on. Thus, you have slot machines with single bets and multiple bet options.


Symbols are very important in understanding slot machines. Without symbols, slot games will most likely have minimal appeal. Traditional slots had symbols that were mostly painted and usually just fruits. However, modern slots are more diverse. They are digitized symbols with many different themes. Besides creating combinations that lead to a win, some special symbols can also trigger a bonus during the game. There are different types of bonus symbols like wild symbols, stacked symbols, multipliers, and scatter symbols.

Dead Spins & Near Misses

When you spin a slot machine reel and lose, it is called a dead spin. Dead spins are spins that result in no payout. A near miss is also a dead spin. However, it occurs when the slot machine reveals a combination of symbols similar to a win but missing a minor detail in the lineup. For example, if the winning combination of symbols is three apples and a spin stops on two apples and a mango, it is described as a near miss.

Different Types of Slot Machines

The versatility of slot machine games is unrivaled. There are hundreds, if not thousands, of slot machines with different themes and graphics, and more are still being designed. Below are the different categories of slot machines.


The mechanical slots of the earliest times are called classic slots. Though some of these still exist in a few casinos, they are mostly hard to find. Some modern slot machines designed to look like the earlier slots are also referred to as classic slots. Classic slots usually have three reels and lesser paylines than most modern slots like video or five-reel slots.

Flat Slot Machines

Unlike progressive jackpot slots, these slot machines have a flat amount as their jackpot prize. Most slot machine games fall under this class of slots and can be found in land-based and online casinos.

Bonus Feature Slots

What is a slot game in the USA or anywhere at all without bonus features? Slots have special symbols that trigger rewards while you play. Examples are Wilds or Scatters. A bonus is unlocked if your spin stops on these special symbols. The most common bonuses offered are free spins and bonus rounds. Some bonus feature slots may also offer a cash prize.

Progressive Slot Machines

When you play a progressive jackpot slot, a portion of your bet is added to a jackpot pool. The pool continues to increase as more players place their bets in the slot and only stops when a lucky player hits the jackpot. They take the accumulated jackpot, and the jackpot pool is reset to start the process again.

Jackpot Slots

Most slots nowadays are in this category. A jackpot slot has a prize that you can win when you hit the specified winning lineup of symbols. Unlike a progressive jackpot, the prize for a jackpot slot is usually smaller.

Online Slots

Like the name, online slots are those you play on the internet. They are web-based and similar to land-based casino gambling slot machines. The main difference is that online slots let you enjoy your slot machine game on your desktop browser or mobile device instead of going to the casinos.

Video Slot Machines

Video slots are preferred by many gamblers. They use digital simulations to create animated reels that add more spice to slot machine games. Video slots may also include scenes from a TV show, movies, or any other effects as designed by the manufacturer.

5-Reel Slots

Though five-reel slots are a type of video slot, both terms are sometimes used interchangeably. They have more reels than the classic three-reel slot machines. As a result, five-reel slots also have more paylines and winning combinations.

Mega Spin Slots

Mega spin slots are special slot types that feature several different games in one. Mega spin slots can have up to four, five, or six slots that you can play all at once. You only have to click the spin button once, and all games begin to spin.


Multipliers are symbols on a slot machine that increase your chances of winning by multiplying your bets.

Multiplier symbols may double or triple your bet

Multi-Payline Slots

Paylines are crucial in understanding all about slot machines. There are single payline and multi-payline slots. The latter are the opposite of single payline slots and are easier to find in casinos everywhere.

Multi-payline slots have more than one payline and can be up to 50 or more.

Unlike single paylines, which are usually straight across patterns, multi-payline slots can let you win with diagonal patterns or even zig-zag lineups.

3D Graphics

These are a subcategory of video slots with special graphic features that make them look more real and more attractive to play.

Branded Slots

These slot machines are designed after third parties like movies, other games, or TV series. Branded slots are also usually named after these parties; for example, The Walking dead slot machine is themed after the famous “The Walking Dead” TV series.

Example of a branded slot machine
The Walking Dead slot

How to Choose Gambling Machine Games

Taking your time before choosing a slot is essential, especially if you’re looking to win real money. While choosing your games does not change your odds, it gives you a better gaming experience and may even affect how much time you get to spend enjoying the game. Here are some things you should look out for when choosing a gambling title:

  • Bet limit. Most slots have a minimum and maximum bet that you can place. Your bankroll will influence your choice of bet type. If you want to play for longer but have a minimal bankroll, it is logical to choose a slot machine with a minimum bet allowance. There are penny slots, nickel slots, dollar slots, and high roller slots depending on your bankroll.
  • Theme. Needless to say, if you’re playing for fun, the slot’s theme is an important feature that may influence your decision. You can go for slots that feature your favorite movie or celebrity, whatever suits you.
  • Jackpots. If you’re looking to win big, it’s best to go for progressive jackpot slots. Though the chances of winning here are slim, the prize money is life-changing, and if you’re lucky, you get to win and cart home the big fish.

Software Providers

We probably wouldn’t be talking about slot machines in casinos if there were no software providers. The brains behind the creation of slot machine games are the software providers. These companies design slot machines that you find in land-based or online casinos. Some of the most popular slot machine software providers are Microgaming, Betsoft, and NetEnt.

Online Slots vs. Land-Based Slot Machines

While many players still enjoy visiting physical casinos, a lot of gamblers now favor online casinos and would rather choose on-the-go gaming. We’re about to define slots in the USA in the table below. It highlights the significant differences between online slots and land-based slots.

Online Slot Machines DefinitionLand-Based Slot Machines Definition
They are cheaper to play; though you may pay the same to play the slot machine, you get to save on travel costs, food etc.More expensive; besides the money you spend on bets, you also have to pay for travel and other costs
You can enjoy playing without any distractionThere is less privacy and more distraction since you won’t be the only one within the casino
Free versions of slot games are very commonIt’s almost impossible to find a free slots in a land-based casino
Games are readily available to playYou may have to wait to play your favorite game if someone else is already using it
You’re free to wear whatever you wantSome casinos have strict dress codes
Can be boring if you are one who enjoys socializing while playing gamesGreat for outgoing players who love to socialize
No free drinks on the houseSome land-based casinos offer free drinks to players

Comparison of Free & Real Money Slots

Free slots meaning for casinos is important: you can play slot machines without using any money. On the other hand, real money slots require making deposits with real money before you can spin. Here are the differences between the two.

Free Money SlotsReal Money Slots
Play for freePlay with real money
It’s mainly for entertainment or practice; there are no chances of winning real moneyYou can play for entertainment while enjoying the chance to win real money
Commonly found in online casinosFound in both online and land-based casinos
No risks involvedThere is the risk of losing money

Strategies for Winning at Slots

You may have heard about slots being a game of chance. That is true. Winning on a slot machine is dependent on luck. But while there are no strategies to guarantee a win, some tips can help you prevent massive losses and have a more enjoyable time at the slots:

  • Practice. This is very important, especially if you’re a newbie. Many online casinos have free versions of slot machine games that you can play without making any payments. This is a good way to get familiar with the game’s symbols and paytables before you play for real.
  • Choose Games with High RTP. Games with higher Return to Players give you a better chance of winning more cash than those with lower RTPs. You should look out for this kind of slot game when playing.
  • Have a Bankroll. This may be the most crucial strategy you will ever need at the slot machine. Playing within your bankroll means you only bet the amount you can afford to lose and leave when you reach your bankroll limit. This way, you stay in control and avoid getting stuck on a losing spree with the hope that you’ll win in the long run.

Look for an online casino that you like, register, and make a deposit. Then, choose your favorite slot game and begin to play. If you want to play for free, you do not need to deposit. Some online casinos will even let you play slot machine games for free without signing up on their platform. However, note that free versions of slot games will not pay you real money even if you win.

Deciding the best slot machine games to play is based on your preference and what you want to achieve by playing. For instance, if you are seeking entertainment, then the best slot machines may be the ones with themes you love. However, slot machines with high RTPs are the best options if you're looking to win real money.

No. Neither a casino nor you can adjust the RNG.

They are 10 * 10 * 10 = 1,000. Therefore, the winning odds on a three-reel slot with ten symbols are 1 in 1,000.

There is no guarantee that playing longer on a slot machine will bring you a win. The result of each spin is random, regardless of how long you play.

Publication Author
Donald Peterson
Author of articles
Donald Peterson is an avid gambler from Edmonton, Alberta, who also writes about his experience with casinos. He’s been in the business for over 10 years, following the ever-changing industry landscape. His articles are aimed at helping beginners with choosing casinos, suitable games, and strategies.
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