Slots are a category of popular casino games where, traditionally, a set of reels spin to unveil different symbols and possible prizes. Slot cabinets, fruit machines, pokies, and more – today, the games are known by many names and come in hundreds of different shapes and sizes, both online and offline.
Especially at online casinos, it is typical to find hundreds of different slot games that can be played, and we even have an abundance of slots that can be played absolutely for free on this website. But how do these games actually work? In this slots guide, we will give you an introduction to everything you need to know about the popular slot games.
History of slots
Slots have a long history that stretches all the way back to the 1800s. It started with so-called poker machines where drums were spun to reveal poker hands. These games became popular in bars but didn't come with an automatic payout mechanism.
There are several precursors to the modern slots, with possibly the most famous being The Liberty Bell – known as the first slot machine. This was a small gambling machine developed by the American Charles Fey from San Francisco. Charles devised an automatic mechanism where three reels with five symbols each spun to reveal wins. By having three reels and five symbols instead of five drums and 50 cards, it became much easier to read wins and therefore wins could be paid out automatically.
After the Liberty Bell was invented and introduced, it quickly became very popular. So popular, in fact, that other slot machine manufacturers copied its mechanism. The first Liberty Bell machine was developed in the late 1880s or 1890s and in the early 1900s, new "bell machines" kept being released.
Over the next 100 years, the machines kept being improved with new developments and designs. More symbols and reels were added and in 1963, the first fully electromechanical slot machine was developed (called Money Honey). This release led to an increasing predominance of electronic games with buttons instead of a lever to start spinning. In 1976, the first video slot machine was developed and in the late 90s and early 2000s, the first online casinos started opening up and offering online slots.
How slots work
While a lot has happened when it comes to the design, features, and themes of slots, today's variants are still based on the first machines developed more than 100 years ago. So how do these games actually work?
Traditionally, slot games come with a set of reels that spin to reveal various symbols. It can for example be five reels showing three symbols each (5x3) or larger grids of six reels with six symbols each (6x6) or more. The symbols shown were traditionally different card-related symbols and fruits, but today the symbols can be anything and everything depending on the theme of the slot.
If the same symbols appear on an active winline, this can result in a payout. But which combinations pay out and which don't can vary a lot from one slot to the next. Some slots pay if the same symbols appear adjacent from left to right only, while others pay for combinations from the right to the left too. Some slots require three of the same symbol on a straight line, while others require more or less, or pay across the reels in other combinations.
And with online slots especially, new mechanics keep getting released – such as clusters of symbols instead of lines or symbols exploding and falling in instead of spinning reels.
In addition to the standard reels and symbols, modern slot games normally come with bonus features and special symbols that make the gameplay more exciting and potential wins bigger. Common bonus features and symbols include:
- Wild symbol: This is a joker that can normally substitute for all other symbols (excluding other bonus symbols) to create winning combinations
- Scatter symbol: This is another special symbol that can trigger bonus features such as free spins or pay out the highest prizes regardless of where it lands.
- Free spins: Many games have free spins as an in-game perk. These are spins that can be spun for free while still having the possibility to trigger real wins. They can often be won by landing certain symbols or completing specific actions.
- Multiplier: Some slots offer a feature where wins can be multiplied (for example doubled, tripled, or more). These can often be gained by landing certain symbols or completing specific actions.
- Bonus game: Many slots also offer games within the game where players might get the chance to gamble their wins, get extra prizes/multipliers/free spins, etc. Again there is normally a special symbol combination or action needed to be completed to trigger the bonus game.
- Jackpot: The jackpot of a slot is the highest possible prize for players. Some slots only offer a fixed, static maximum prize, but others come with a progressive jackpot. This is a jackpot that keeps increasing in size for each bet placed (locally in the casino or a network of casinos offering the game) until a lucky winner lands it.
- Buy feature: Normally, players have to take their chances and wait for lady luck to reveal different bonus symbols and features. But in some newer slots, it is possible to "skip to the bonus" by buying it. Players can then spend part of their playing funds to access a specific bonus game or similar.
The mathematics of slots
Slot machines are a game category purely based on luck. With the exception of some bonus features, such as the possibility to buy direct access to a bonus game, it is 100% up to chance what will happen. The games are therefore largely based on mathematics, with percentages, probabilities, and so on. When playing slots, some statistics-related terms to know about include:
- Return to player (RTP): The RTP of a slot is the theoretical payout percentage over time. A slot can for example list that the RTP is 96%. This means that out of €100 bet, on average, €96 is paid back. Players can use the RTP to get an idea of how much is paid back of bets placed. This is not a guarantee though, as it is an average based on millions of game rounds where some players lose, while others win.
- House edge: The opposite of the RTP is the house edge. If players on average get 96% paid back, it means that on average, 4% go to the casino. The house edge of slots is normally between 3-10% (97-90% RTP).
- Variance: Another term to note is variance (and volatility). Slots are sometimes listed as having a high, medium, or low variance. This tells something about how often wins hit as well as the size of those wins.
- High variance slots don't pay out wins that frequently, but when they do, they tend to be bigger (high risk - high reward).
- Medium variance slots pay out wins at an average pace and size (medium risk - medium reward).
- Low variance slots pay out wins quite frequently, but they are quite small (low risk - low reward).
How to play online slots
Slot machines started out as physical machines – and these can still be found at land-based casinos and other brick and mortar establishments to this day. But additionally, slots can be found and played in thousands of different versions online. The setup and gameplay will work similar to the physical machines, but as mentioned, there might be additional features such as bonuses or unique ways of rewarding wins.
When playing online, there is no lever to pull or physical button to push to spin the wheels. Instead, you will see the game grid and all buttons and settings on your screen. At the bottom of the screen, in the middle, there is normally a button you can click to spin the wheels. This will spin them one round and once they stop, you can see the symbols they landed on.
If the combinations create any wins, these will be counted and added automatically. Changing the size of how much you want to bet or other settings such as turning sounds on or off can be done with a simple click of a button. And most online slots are developed to work well on mobile devices as well as desktops.
Since slots are purely based on luck and don't require the use of any strategies, they are quite easy to get started with. But in order to familiarize yourself with how the game goes and which games you like the most, we recommend starting out with some free slots. Luckily you can do so right here at Temple of Games, by browsing our selection of free slots and choosing the games you would like to play. If you later want to try to play some of the games for real money, you can do so by signing up at a legit and fair casino from our casino recommendations.