Slot Features And How They Work

Slot features are part of what differentiates slot games and make them fun and exciting.

But features are more than variations on a theme or only about entertainment. Features can increase your chances of winning, which is something everyone wants. To maximize the opportunity to increase your winnings, you must know what features are available, how they work, and how to choose the right ones.

What are slot features?

Slot features are added to slots to make the game more exciting and increase your wins. The idea is that the more exciting the game and the more you win, the more you will play.

Some slot features look intimidating if you are new to slots or don’t know the features or how they work.

Don’t be intimidated! Slot features are designed to be fun, not frightening. The slot game designers want you to play and have fun playing. The key is learning what these features are and how to use them.

Reels, paylines, and symbols

All slot games have reels, paylines, and symbols.

  • The reels are the vertical spinning parts.
  • The paylines are imaginary lines across the reels.
  • The symbols are the images on the reels.

How to read the paytable on a slot machine

The first step to understanding slot features is knowing how to read the paytable. The paytable shows how much each symbol pays and how to activate the bonus round. Generally, bonus rounds are free spins but can also be a separate game.

The paytable also details the paylines, RTP, hit frequency, volatility, and max win. These are important in determining which slot and feature you want to play to maximize your wins.

  • RTP is the Return To Player, the percentage returned over the long term. If the RTP is 97%, for every $100 you bet over the long term, you can expect a return of $97.
  • Hit frequency is the likelihood of a slot hitting a winning combination of symbols. Most slots have a hit frequency between 20% and 30%. The higher the hit rate, the more likely you are to win.
  • Volatility is how often a slot will win and the size of the wins. High volatility slots pay larger amounts less often. Low volatility slots pay smaller amounts more frequently.
  • Max win is the maximum you can win on the slot. It is usually stated as a multiplier. If the maximum win is 5,000 times the bet (5,000x), the most you can win is 5,000 times your bet. If you bet one dollar, the max win is $5,000.

Whether you lose, win, win big, or hit a max win is determined by the random number generator.

What is a random number generator?

Possibly, the most frequently asked question is whether live and online slot machines are rigged or random. They are random. Every spin is based on a random number generator.

Thousands of random numbers are generated every second, and the moment you press the spin button, the number generated determines which symbols land where.

What are the different types of slot features?

Now that you understand how slots work, it’s time to learn about different types of slot features.

Fixed and variable paylines

When slots were first introduced, winnings were paid when three or five symbols, depending on the number of reels, lined up on the center payline. The center was the only payline. Additional paylines and the number and combination of symbols are much more complex on today’s video slots and a part of many slot features.

Today’s slots come in two versions, fixed and variable paylines:

  • Fixed paylines in which you must bet on every line. On a 20 payline game, each bet will pay on all 20 paylines.
  • Variable paylines in which you choose how many paylines you want to bet on with each spin. On a 20-payline game, you bet on one to 20 paylines. The more paylines you want to bet on, the more money you have to bet.


Autoplay is one of the most common slot features, and it is exactly what it says it is. With the autoplay feature, play is automatic. You do not have to hit the spin button. The computer does it automatically.

This is a nice feature if you are doing another task that requires your hands, like washing the dishes. With autoplay, you need only click the autoplay button once, and play is initiated continuously.

Often, you can set the number of spins the slot will autoplay (10, 50, 100, etc.). You can also have the game stop at a predetermined amount so you don’t lose too much or if you win big and want to walk away with the winnings. Autoplay stops for bonus rounds.


Wilds are a standard feature on almost every slot. A wild symbol can represent any symbol in the game to make a winning combination.


Scatters are basic features of most slot games. Scatters are symbols that trigger bonus games such as free spins or mini-games. They may also trigger multipliers or wilds. It usually takes three or more scatters to trigger the bonus, multiplier, or wild.

Progressive jackpots

Progressive jackpots are the ultimate slot payout. They differ from standard pay table winnings because the winning amount is determined by how much is bet over time.

Progressive jackpots begin with money from the casino, and then, as people play the slot, a small percentage of each bet is added to the jackpot. The more that is bet, the larger the jackpot.

For example, Megabucks is a Las Vegas progressive jackpot. It starts with $10 million and grows from that point. To win Megabucks, a maximum bet is required, and the Megabucks symbols must line up.

Gamble feature

The gamble feature is common on many, but not all, slots. It kicks in after you win.

Once you’ve won, you can risk the payout in a simple 50/50 game of chance, such as a red or black, high or low game. When you win the gamble feature, you double your winnings. But if you lose, you lose everything.

A variation of the gamble feature is a choice of how much of your winnings you want to use so you don’t end up risking all of your winnings.

Adjacent Ways

Adjacent ways slots have no paylines. Wins are determined by matching symbols anywhere on the reels.

For example, on a one-line payline slot, a winning symbol must line up starting on the first reel and be on the center line to win. With an adjacent ways game, the symbols can be anywhere on each of the reels, and if the slot has more than three reels, the winning symbol does not have to start on the first reel. The winning symbols need only be adjacent to each other.

There are two variations of adjacent ways slots.

  • Adjacent ways pay – Starting on the first (left) reel and working toward the right side on any line. This is the most common adjacent ways feature in slot machines.
  • All ways pay – The matching symbols can be anywhere on the reels, but they don’t have to start with the first (left) reel.

Both variations increase your chances of winning.

Cascading Reels

Cascading reels go by several different names depending on the slot developer:

  • Collapsing reels
  • Tumbles or tumbling reels
  • Avalanches
  • Rolling reels
  • Symbol drops
  • Chain reactions

Regardless of the name, cascading reels trigger when you hit a winning combination. You collect the win, and the winning symbols disappear, leaving open spaces in the reels. The symbols above the open spots drop down and fill the empty spaces. The rest of the open areas receive new symbol replacements, possibly leading to another win.

The Cascading Reels feature usually triggers itself. And as long as you are winning, the cascade continues.

A variation of this feature is a multiplier on each consecutive cascade win, significantly increasing your winnings.

Cluster Pays

Cluster Pays is more than a feature; it is a different way of playing slots. Cluster Pays replace paylines and adjacent ways with groupings of the same symbol.

The game is played on a grid formation from four to 20 symbols. Paytables are more extensive on Cluster Pays slots, and winnings are paid based on the size of the cluster. For example, a four-symbol cluster may pay two times the bet, while a ten cluster might pay 100 times the bet.

Clusters do not have to be in a square formation, such as 2X2 or 3X3. They can be an ‘L’ or ‘T’ shape, any formation as long as two or more symbols are clustered together.

Mystery Symbols

If you like surprises, you’ll enjoy the mystery symbols feature. Mystery symbols are specific images appearing in the reels, like a question mark or a closed door.

Before a win is paid or before the next spin, if you did not win, the mystery symbols flip to reveal the symbol behind them. This can increase your winnings or chances if you have not already won.

In a variation of mystery symbols, more than one symbol is hidden under the mystery symbols, increasing your chances of winning.

Win Both Ways

In a regular slot game, if you don’t see a winning symbol on the first reel, you already know you’ve lost while the remaining reels complete their spin. This is no fun.

But with Win Both Ways, as the name suggests, you win if the symbols line up both ways, left to right or right to left. So even if the first reels are duds, you could still win if the last three reels match with winning symbols.

243 Ways to Win

On most slot games, there are five reels and three rows. This equals 15 total places for symbols, 3 x 5 = 15.

With 243 Ways to Win, instead of paylines, this slot feature pays when adjacent matching symbols start on the first reel on the left and run toward the right side. Therefore, any combination of three or more matching symbols is a win if they start on the first reel and don’t skip a reel.

For example, if you have a cherry anywhere on the first, second, and third reels, you’ve got an instant three-of-a-kind. The more cherries you add, the more payouts you receive.

The 243 in the name comes from multiplying the number of symbols needed for a win, three times each the of five reels, 3 x 3 x 3 x 3 x 3 = 243.

720 Ways to Win

The 720 Ways to Win features has a slightly different reel configuration. Most slot games have five reels, and each reel has three symbols. With this standard setup, the reels are shaped like a rectangle.

In 720 Ways To Win, the first reel has three symbols, the second reel has four symbols, the third reel has five symbols, the fourth reel has four symbols, and the fifth reel has three symbols. In this setup, the reels are in the shape of a diamond.

If you multiply each reel by the number of symbols in each reel you can see where the 720 in the name comes from, 3 x 4 x 5 x 4 x 3 = 720.

Like 243 Ways To Win, a winning combination must start on the first line. Because the first reel in 720 Ways To Win has only three symbols, it limits your chances of a win, which leads us to 1,024 Ways to Win.

1,024 Ways to Win

1,024 Ways to Win is an extension of 243 and 720. This feature has five reels with four symbols each. And you probably know by now that four symbols on five reels equals 1,024.


If you like 1,024 ways to win, you will love Megways with 117,649 ways to win!

Wins are calculated the same way as 243, 720, and 1024 Ways To Win features, but the reels in the Megaways feature have different-sized symbols. This means the number of symbols each reel has can change with each spin.

The most symbols a reel can hold is seven, and there are six reels. Thus,  7 x 7 x 7 x 7 x 7 x 7 = 117,649.

Expanding Reels

Expanding Reels looks like a standard slot game with five or six reels and three or four rows of symbols. But the reels expand to allow for more rows and symbols.

Some games have expanding reels only in the bonus round, and other games expand with winning combinations.

Expanding Wilds

Expanding Wilds is precisely what the name implies. When a wild lands, it expands to fill the entire reel. This feature usually happens when a single wild is on a reel that could make a payout difference.

Expanding Symbols

Expanding Symbols is one of the best online slot bonus features. Usually, a designated symbol is chosen randomly before a free spins round starts. When that symbol hits it expands to cover the reel.

With Expanding Symbols in the bonus round, three symbols on any three reels guarantee multiple three-of-a-kind wins.

Sticky Wilds or Locked Wilds

Sticky Wilds are used in the main or bonus round. When you hit a wild, it stays in its position for a while. As more wilds show up and are locked in place, your bonus win grows nicely.

Transferring Wilds

When wilds come up on the first two reels, they are copied, usually in the same position, to the other three reels.

Walking Wilds or Shifting Wilds

The Walking Wilds feature is in the bonus as part of the respin. When a wild appears on a reel, it moves from reel to reel, right to left, with each spin until it ‘falls off’ after the first reel.

Random Wilds

The difference between Random Wilds and regular wilds is that Random Wilds don’t spin into the reels like the other symbols. Instead, they randomly pop into the reels, taking the place of the symbol that was there.

Stacked Wilds

A Stacked Wild is a single wild symbol covering two or more places on a reel. A Stacked Wild may cover the entire reel.

Colossal Reels

Colossal Reels are usually in the bonus round and have two reels on the same screen. The first is a small set of reels, such as five reels by three rows. The second set is much larger, maybe five reels by 12 rows. This results in a large number of paylines and a lot more chances to win.

Synced Reels

Synced Reels happen while the reels are spinning. One reel syncs with another reel when the symbols match. All the reels can sync for a big win.


The Respin feature is quite common. It is simply a free spin. But it’s not always a new spin. For example, if you have a wild symbol and a Respin comes, the wild may stay while the other symbols spin again.


The Re-trigger feature results in another bonus while playing a bonus. The Re-trigger feature retriggers the bonus.

Nudges or Nudging Reels

Nudges push the reels up or down by one or more symbol places to get a winning set of symbols.

For example, if you have two winning symbols inline on reels 1 and 2 and a third winning symbol just below or above on reel 3, then the winning symbols on reel 3 would be ‘nudged’ into the pay line with reels 1 and 2 for a win.

Horizontal Reels

Rather than spinning vertically from the top of the reel to the bottom, Horizontal Reels spin horizontally from left to right.

Split Symbols

The basic idea is to add symbols to the reels. Split Symbols double up as two symbols on one reel space. This gives you the chance to increase your wins.

Symbol Transformations

As the name says, some symbols transform from low-value into high-value symbols or change from one image into another to increase your chances of winning.

Buy a Bonus

This feature allows you to buy a bonus rather than wait for one to appear on a spin randomly.  But it can be costly, 50 to 150 times your bet. Variations include paying more for better odd or more free spins.

Fruit Machine Hold

The hold feature makes a fruit machine different from a regular slot. Fruit machines are different because they include an element of skill. The skill is in the ‘hold’ strategy.

You can hold one or more reels in place to increase your chances of winning while the other reels spin. The number of reels you can hold depends on your number of holds. You get a certain number of holds that must be used in a limited time. This is where the strategy comes into play.

Exploding Wilds

With the Exploding Wilds feature, there is a countdown meter on the screen. It starts at ten and goes to zero with each spin.

As you spin, a special symbol may appear, which will ‘explode’ when the countdown reaches zero. The exploding symbols become wilds on the reel and line they appeared. After you collect your winnings, the countdown meter starts again.

Double Stacks

When a reel stops spinning and contains a double stack symbol, every symbol on that reel counts as two symbols. On free spins, wilds are also doubled.

This list of 34 slot features is not exhaustive. Developers are always coming up with new features to differentiate their slots and ways to make slots entertaining and fun.

How to choose the best slots with features

With so many features and feature combinations, how do you choose the ones best for you? It’s not easy. Follow this list to narrow it down so you won’t be overwhelmed.

  • Read the Paytable: This is where you will find the rules, what the symbols mean and pay, special features, and how to activate those features. You will also find the betting range, max payout, and RTP.
  • Play in Demo Mode: This is the best way to experience the game risk-free and decide if it’s a game for you.
  • Read Slot Reviews: Slot reviews are a great way to get honest opinions of the slots from real players. They often provide information you might not get elsewhere or by playing the demo mode.
  • Favorite Developer: Software companies primarily develop slot games. These companies have unique styles of graphics, features, and mechanics. As you play different games, note who the developer is; you may discover specific developers as your favorites.
About the Author

Walter Yuhl

Walter (Way) Yuhl is a freelance writer and business professor. Way has written for the Arizona Daily Sun, Flagstaff Business News, Bangkok University, and Shandong University of Science and Technology as well as edited content for the U.N., Thailand International airports, and other organizations. He has worked with Cantena Media since 2019.