Playing a slot machine can bring hours of entertainment and excitement, but like many games, these popular devices have their distinct terminology. Beginners may be a bit overwhelmed when playing at a live casino or on an online gaming platform.

From jackpots and payout percentages to bonus games and progressive games, numerous terms exist to learn and consider when jumping into the action. While not a complete grasp of all the ins and outs of a slot isn't required, having a basic knowledge can be understandable.

With that in mind, here's a look at some of the terminology that goes along with playing a slot at your local casino or simply on your mobile phone. This article offers readers everything they might need to know about slot terminology and some of the key concepts synonymous with slot machines.

Slot Payout and Money-Related Terminology

These terms involve a player's money and credits on a machine. You'll find these terms helpful in adding credits to a machine, determining how much to play for, and what to expect when cashing out.

Balance – This is the amount of money you have in the machine. Once you deposit your money, you should see this on-screen in the form of credits for that machine. For example, if you slide $100 into a 25-cent machine, the balance should be 400 credits. This amount goes up and down depending on winning and losing spins.

Cash-out – This simply means taking your funds out of the machine. There is usually a "cash out" icon on the screen or a real button on the machine itself. Once a player has cashed out, he or she will receive a voucher. This can be used in other slots instead of cash or can be taken to the cashier to exchange for cash as well. Online slot players can also cash out their winnings and go to a different game.

Coin-in – This is an industry term for the amount of money input into a machine. Slot machines pay a certain percentage of coin-in back to players.

Credits (also known as units) – This is the amount of a coin-in you have inserted into a machine. A single credit is the lowest denomination allowed on a machine. For example, a player on a penny machine may put in $20. That would mean the player would have a balance of 2,000 credits to begin the session.

Minimum bet – As the name implies, this is the minimum credit that can be bet on a certain slot game online or in a live casino.

Payline –  These are the lines on a machine or online slot where the game's symbols must line up to determine a winner. The paylines can be horizontal but also vertical, diagonal, and run in other directions, especially on video slots. On more traditional-type slots, these can be found right on the exterior of the machine in front of the reels. However, on video slots, the paylines can be determined in many ways and the machine will visually display the multiple ways a player has won using paylines. Also, players have the option to play numerous paylines on modern video slots as well. This system can also be found on online free slots.

Active payline – These are all the paylines in play during a certain spin of the reels. A player with the max paylines will have all paylines active on each spin.

Payout Percentages (also known as RTP, meaning a return to player) – This is the amount of coin-in paid back to players at a particular casino. These numbers are usually available online, and finding properties with better payout percentages may offer a better chance for players to win. Players may want to look for rates above 90 percent. Occasionally, some of these get higher than 95 percent.

Pay Tables – This is a chart (or table) found on the machine itself or the screen of a video slot. This details the combinations that will win and how much they return depending on the slot machine symbols that appear on the machine. The table features several rows to show higher levels of combinations and also columns that show various payouts depending on the number of credits paid per spin.

Progressive Slots – Progressive jackpots are slot games that are linked to a certain region or jurisdiction. A certain amount of each player's spin is siphoned into a much larger prize pool. With so many players linked together, those player pools can grow extremely large. Online slot players can also benefit from playing these types of games as well. Some of these mega jackpots regularly pay out seven figures; historically, some have even reached eight figures. Click here to learn how to play progressive slots.

Ticket or voucher – The paper coupon printed by a slot machine when a player cashes out. This functions as cash at a slot machine and can be input at another slot to continue playing. You can also exchange these for real cash at the casino cashier or kiosks throughout the property.

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Slot Gameplay Terminology

Auto-play/Auto-spin – This is a setting on a slot where the reels spin automatically and a player doesn't have to keep hitting the "spin" button. Auto-play spins the reels automatically for a certain amount of time, with atop-spin keeps the reels spinning for a certain number of spins.

Basic slot – This is a traditional-style slot with only one payline and fixed payouts.

Bonus game – This is an extra game aside from the normal spinning of reels on a game. Players can activate these bonus features depending on a combination of symbols that show up on the machine. These games may have players making certain selections or competing in other forms. Bonus games offer players a chance at more significant wins and can help create a winning session.

Second screen bonus – A bonus game that shifts the action to another screen, often found above the main screen. These usually offer players options and other secondary games to determine further winnings and possibly a jackpot.

Cascading reels (also known as tumbling reels) – This is another fun twist seen on some modern slots where certain symbols disappear, with others sliding in to take their place.

Free play – These are free spins often given to players who join a casino's slot club (also known as a players club or a rewards club). Many casinos offer a certain amount of free play just for signing up for the club. You may also earn free play as you accumulate reward points for playing.

Free spins – This is a type of bonus that certain symbol combinations in a game can also trigger. The game often begins spinning the reels automatically and counts down from the free spins. Players can accumulate wins and credits without having to dip into their balance. This offers an opportunity for players to accumulate extra wins toward a nice session.

Hit frequency – This is the term used for the number of times a slot may be expected to pay out.

Hopper – This type of machine features an option where players can keep certain lines on one spin and then "hop" them into another. This gives players an extra shot at landing highly-sought combinations that might result in larger wins.

Jackpot – This is a larger than the typical payout on a slot machine. Players will usually find that games in a live casino and online have several jackpot tiers, from a small jackpot to even much larger payouts. These are often mini, major, minor, and mega jackpots. That range offers players multiple ways to win more than the average amount that can be found on an average spin of the reels. Players on online slots also have a shot at these jackpots.

Loose slots – These slots are deemed to have a high payout percentage, meaning that a higher-than-normal amount of coin-in is paid back out to players. These offer players a higher chance at a winning session.

Max bet – A player is betting the maximum amount of credits per spin allowed on a machine. There is often a "max bet" button on the machine itself or as an icon on the screen. Max bets pay the most for win on the pay table. Players usually have from one to five credits allowed to be played per spin.

Mobile slots – Games that can be played on a mobile phone or tablet device. This is a fast-growing segment of real-money casino gaming, but this can also refer to free-to-play games. In addition, social gaming in the form of fun and free slot games has also seen significant growth in the gaming industry.

Multiplier – This symbol or image allows players to see their point total multiplied by a certain amount if activated.

Nudge slot – This is a popular feature on many modern slots in which machine may "nudge" the reels up or down into a winning position. What may have looked like a losing spin may turn into a winner once the nudge function repositions the symbols on the reels.

Reels – vertical cylinders spin within a traditional slot machine that display various symbols to help determine a player's win or loss. Originally, these were mechanical devices, and where they stopped was totally determined by the mechanics of the machine. In modern slots, however, the random number generator (RNG) determines a winning spin. Many games that look like traditional machines may still have reels, but the RNG still determines where they stop and with what symbols are displayed. Video slots, including digital online and social gaming slots, also feature "reels". Still, these are simply graphical, but mimic a slot's traditional look and feel but with modern gameplay twists.

Three-Reel Slot – As the name implies, these are simply games featuring three vertical reels as found in traditional slots

Five-Reel Slot – This is just simply a game with five spinning reels. There were three reels when slots were invented, but games have expanded through the years to offer more reels and ways to win.

3-D slots - 3-D slots are modern video slots often found online that feature three-dimensional images and graphics.

RNG – This stands for "random number generator" and is the key to how the results turn out on a modern slot game. No longer do machines make use of mechanical reels to determine if a player wins. Instead sophisticated software and casino algorithms are used as part of the machine's random number generator to determine completely random winners.

Slot tournaments – These are multi-player contests in which players spin the reels of a slot machine in competition. Casinos often run these as promotions for loyal players. Slot tournaments are often large payouts and other prizes from the casino for winners.

Symbols (also known as icons) – These are the graphical images used on the front of reels as well as on video and online slots that visually display a slot result. If the RNG determines a win then these will align in a certain pattern or combination. Traditional and historic symbols include fruits, bars, 7s, playing cards and suits, and much more. Video slots now use numerous symbols, video, and other graphical elements.

Wild multiplier – A wild symbol that can activate a multiplier when triggered, giving a player more winnings than might otherwise have been awarded. Those winnings are multiplied by a certain amount.

Other slot terms

Here are some other terms players may want to know as they begin playing slot games.

Free play – This is free slot play usually given to players as a reward for a certain accomplishment. Many casinos offer free play for those who join the casino's rewards program. Regular players in a players club may also earn free play as they accumulate rewards points.

Hold percentage – This is a casino's amount of all money played into a slot machine. This is the house edge and the money a casino collects from all players' coin-in.

Hot and cold slots – Generic terms for a machine that has been paying out a lot (hot) and one that hasn't been paying out (cold). However, these notions are mostly a myth with modern slot machines, as the RNG determines random winners.

Lever – This is a remnant of early slots in which a player pulled a lever on the side of the machine to spin the reels. Modern technology has made this part of a slot machine obsolete. However, some machines still offer a lever as a throwback to those classic machines. You can pull the lever to activate the reels, but the lever doesn;t actually have a mechanical function. The machine's computer activates the reels with the lever functioning like the "spin" button.

Licensed slots – This refers to a game using a popular character, TV show, movie, or other brands in pop culture. This has become a trend in modern slot games, with more manufacturers offering players a bit of pop culture or nostalgia.

Mechanical slots – This refers to older, classic mechanical slot machines that feature real mechanical mechanisms inside the machine. Modern slots no longer need mechanical parts or a lever crank to get the reels spinning.

Mobile slots – These are just online slots that can be played on a cell phone or tablet device.

Multi-line slots – These are games that feature numerous paylines beyond just the traditional horizontal paylines found on older machines.

Players club (also known as a loyalty or rewards club) is the casino's program to reward loyal players. Those who play often at the casino can earn free play., hotel stays, food comps, and other prizes. It pays to join the rewards club. Players will receive a player card to insert every time they play a slot game. This helps track your play so that you accumulate points based on your play. Online casinos may also have rewards programs that offer prizes and bonuses.

Volatility – Refers to a game's payout frequency. Those with a "high volatility" pay out high amounts but with fewer payouts overall. "Low volatility" slots pay out more often but in smaller amounts overall.


These are some basic terms a player may want to be familiar with when heading to play some slots. However, don't get overburdened with jargon. Instead, learn the basics, know what you're getting into, and have fun!

Frequently Asked Questions

What is the meaning of the term "balance"?
The balance is the amount of money a player has in a machine in the form of credits.

What is the meaning of the term "payline"?
Paylines are the lines on a slot machine or online slot where the game's symbols must line up to determine a winner.

What is the meaning of the term "progressive slots"?
Progressive slots are slot games that are linked over a certain region or jurisdiction. A certain amount of each player's spin is siphoned into a much larger prize pool.

What is the meaning of the term "pay table"?
The pay table is a chart or table found on the machine itself or the screen of a video slot. This details the combinations that will win and how much they return depending on the slot machine symbols that appear on the machine.

What is the meaning of the term "wild multiplier"?
A wild multiplier is a wild symbol that can activate a multiplier when triggered, giving a player more winnings than might otherwise have been awarded.

What is the meaning of the term "players club"?
A players club, also known as a loyalty or rewards club, is the casino's program to reward loyal players. Those who play often at the casino can earn free play, hotel stays, food comps, and other prizes.

Sean Chaffin
Sean Chaffin

Sean Chaffin is a longtime freelance writer, editor, and former high school journalism teacher. He has covered the poker and gaming industry for many years.