Slots Terminology: Your Plain-English Glossary of Slot Machine Terms
Slots terminology covers the words you see on a slot’s game screen, paytable, and information panel – from reels and paylines to RTP, wilds, bonus features, and jackpots.
This plain-English glossary is for new players learning the basics and experienced players who need to check an unfamiliar term.
Everything is grouped by theme, so you can scan directly to the section you need and follow the links where a topic deserves a deeper explanation.
The Basics – Reels, Rows, and Symbols
The Game Screen
Reel: One of the vertical columns that displays symbols. When you press spin, the game produces a result and the reels animate to show it. Many online slots use five reels, but layouts vary.
Row: A horizontal line of symbol positions across the reels. The reels and rows combine to create the game grid.
Symbol: An icon that appears on the reels. Regular symbols can form winning combinations, while special symbols may substitute for others, trigger bonus features, or change how the game works.
Spin: One complete round of play. Your stake is deducted, the game generates an outcome, and any winning combination is evaluated according to the paytable.
Bets, Balance, and Game Rules
Stake or bet: The amount wagered on one spin.
Coin denomination: The value assigned to each virtual coin or betting unit in games that use a coin-based control. Changing the denomination usually changes the total stake without changing the underlying rules.
Bet size: The total amount wagered on one spin. Depending on the game, it may be calculated from the coin value, number of coins, number of active lines, or a simple total-bet control.
Max bet: The highest stake the game allows for one spin. A Max Bet button may select the highest available amount, so check the total before using it. Some jackpots have a qualifying-bet condition, but this is game-specific and should be confirmed in the paytable.
Balance: The amount currently available in your account or game session. Stakes reduce it, while payouts add to it.
Bankroll: The budget you set aside for playing. It does not change a slot’s odds; it helps you control how much you are prepared to spend.
Paytable: The game’s rules and payout guide. It explains symbol values, winning combinations, special features, RTP or volatility where published, and any conditions attached to jackpots or maximum wins. Look for an info icon, question mark, help menu, or rules button inside the slot window.
Our guide to how to read a slot paytable explains what to check before you spin.
With the game screen covered, the next step is understanding how those symbols form a win.
Ways to Win – Paylines, Payways, and Clusters
Paylines and Active Lines
Payline: A fixed path across the reels on which matching symbols must land to create a win. The required direction, number of matching symbols, and payout are set by the paytable.
Active payline or active bet line: A payline included in your wager. Some traditional slots let you choose how many lines to activate, while many modern line-based games keep all paylines active.
Payways and Clusters
Payways or ways to win: A system that replaces fixed paylines. Matching symbols usually need to land on adjacent reels from left to right, but they can appear in different rows.
A standard five-reel, three-row layout can produce 243 ways to win because every position on consecutive reels can contribute according to the game rules.
Paylines and payways are not the same: paylines follow preset paths, while payways count combinations across reel positions. See our guide to payways vs. paylines for a fuller comparison.
Cluster pays: A win system that rewards groups of matching symbols touching horizontally or vertically instead of following lines. The number of symbols needed varies by game.
Learn more about cluster pays slots.
Wins and Frequency
Winning combination: A group of symbols that meets the game’s rules for a payout. It may appear on an active payline, across adjacent reels, or in a cluster.
Payout or win: The amount credited when a result matches a winning combination or feature award. The amount depends on the paytable, the symbols or feature involved, and the stake.
Hit frequency: The theoretical percentage of spins that return any win, including wins smaller than the stake. It describes how often wins occur, not how large they will be.
Our guide to paylines and hit frequency explains how the two ideas connect.
Once you know how wins are counted, the special symbols and bonus mechanics are easier to follow.
Special Symbols and Bonus Features
Wilds
Wild symbol: A symbol that substitutes for specified regular symbols to help complete a winning combination. Wilds do not usually replace scatters or bonus symbols unless the paytable says otherwise.
Stacked wild: A wild that occupies two or more consecutive positions on the same reel. Not every stacked wild fills the entire reel.
Expanding wild: A wild that grows after landing, often filling its entire reel or a defined part of the grid.
Read more about stacked vs. expanding wilds.
Sticky wild: A wild that remains in place for more than one spin or for part of a feature while the other positions continue to change.
Walking wild: A wild that shifts to another position or reel on consecutive spins, usually until it leaves the grid.
See how these mechanics differ in our guide to sticky and walking wilds.
Scatters and Free Spins
Scatter symbol: A special symbol that may pay or trigger a feature without following a standard payline. Its exact role, required quantity, and eligible reel positions are defined in the paytable.
Free spins: Spins awarded within a game feature without an additional stake being deducted for each spin. They may include multipliers, special wilds, or retriggers. Promotional free spins offered by a casino can have separate terms.
Bonus Rounds and Feature Mechanics
Bonus round or bonus game: An extra game feature outside the standard base-game spin. It may use free spins, respins, prize picks, wheels, or a separate grid.
Pick-me feature: A bonus game in which you choose from several hidden items to reveal prizes or modifiers. The choices and awards are determined by the game rules.
Multiplier: A feature that multiplies a payout by a stated amount. A 5x win multiplier turns a $10 win into $50. A bonus multiplier applies during a bonus round, while a wild multiplier applies when that wild contributes to a win.
Hold and Win: A respin feature in which specified symbols lock in place while the remaining positions respin. New qualifying symbols commonly reset the respin counter, and the feature may include fixed jackpot tiers.
Read our guide to the Hold and Win mechanic.
Bonus Buy or Feature Buy: An option that lets you pay a stated multiple of your stake to enter a bonus feature directly instead of triggering it through base-game play. Availability, cost, and game settings vary, so check the paytable.
Learn more about bonus buy slots.
Reel and Grid Mechanics
Cascading or tumbling reels: After a win, the winning symbols disappear and new symbols fall into the empty positions. This can create another result from the same paid spin.
See our guide to cascading reels.
Pays Anywhere: A mechanic that awards qualifying combinations when symbols land in permitted positions anywhere on the grid rather than on fixed paylines. The exact matching rules vary by game.
Infinity Reels: A branded expanding-reel mechanic in which qualifying wins can add reels and continue the sequence. It is not simply another name for Pays Anywhere.
Our guide to Infinity Reels and Pays Anywhere explains both systems.
Features explain what can happen on the reels. The next group of terms explains the math behind how often and how much a slot is designed to pay over time.
The Math – RTP, Volatility, and House Edge
RTP and House Edge
RTP or Return to Player: The theoretical percentage of total stakes a slot is designed to return over a very large number of plays. A 96% RTP does not mean you will receive $96 back from a $100 session; short-term results can vary widely.
House edge: The casino’s theoretical mathematical advantage over the long run. For a slot with a 96% RTP, the corresponding theoretical house edge is 4%.
Volatility and Hit Frequency
Volatility or variance: A description of a slot’s payout pattern. Low-volatility slots tend to produce smaller wins more frequently, while high-volatility slots tend to produce wins less often with the potential for larger payouts. Medium-volatility games sit between the two.
Volatility and hit frequency are related but different. Hit frequency describes how often a win occurs; volatility also considers how the game distributes payout size.
Read more about what volatility is and how slot volatility is measured.
RNG and Independent Spins
RNG or Random Number Generator: The system used to generate random game outcomes. In an online slot, the result is mapped to reel positions and then displayed as symbols on screen.
Each spin is independent. A previous win, loss, bonus, or jackpot does not make a particular result more or less likely on the next spin.
Testing standards evaluate the RNG, game mathematics, rules, and implementation together. The presence of an RNG alone should not be treated as a guarantee that every part of a game has been implemented correctly.
Learn more about why slots use random number generators.
Hot and Cold Slots
Hot slot and cold slot: Informal player terms for a game that has recently appeared to pay frequently or infrequently. They describe a past streak, not a future state.
Because spins are independent, a ‘cold’ slot is not due to pay and a ‘hot’ slot is not guaranteed to keep paying.
The math describes a game’s long-term design, but jackpots use a few additional terms of their own.
Jackpots and Big-Win Terms
Fixed and Progressive Jackpots
Jackpot: A top prize or one of the highest prize tiers available in a slot. The trigger and value are defined by the game rules.
Fixed jackpot: A jackpot with a set value or bet-based multiplier that does not grow through progressive contributions. Its displayed cash value may still change with the stake if the paytable defines it as a multiplier.
Progressive jackpot: A jackpot that increases according to the game’s rules as qualifying play occurs or as time passes. After it is won, it normally resets to a starting amount.
See the different types of jackpots or read our full guide to progressive jackpots.
Local, Networked, and Must-Drop Jackpots
Local progressive: A progressive jackpot shared within one game or a limited group of games on a single casino or site.
Networked progressive: A progressive jackpot shared across multiple connected games, machines, or casinos.
Must-drop or Hot Drop jackpot: A jackpot designed to be awarded before a stated value is reached or before a countdown expires. The exact trigger and deadline are set by the jackpot rules.
Maximum-Win Terms
Max win: The highest payout a slot can award under its rules, often shown as a multiple of the stake. It is a possible game outcome, not a prediction for a session.
Multiplier ceiling: The highest multiplier a feature or meter can reach. It is not necessarily the same as the game’s overall maximum payout.
For a deeper look at multiplier mechanics, visit our guide to multiplier slots.
Speak the Language, Then Spin
You now have the slot machine terms needed to read a paytable, compare win systems, understand bonus features, and interpret figures such as RTP and volatility.
The most important habit is still to check the rules for the specific game. Familiar terms can work differently from one slot to another, and the paytable is the best source for the exact conditions.
When you are ready to see these terms in action, explore the real-money slots at SlotsLV Casino.
More About Slots Terminology
What are the basic slot machine terms?
The basic slot machine terms are reel, row, symbol, spin, stake, payline, and paytable. Together, they explain the game layout, the amount wagered, how wins are formed, and where the rules are shown.
What are the parts of a slot machine called?
The main visible parts are the reels, rows, symbols, balance display, bet controls, spin button, and paytable or information screen. Their exact layout varies by game and provider.
What is RTP in slots?
RTP is the theoretical percentage of total stakes a slot is designed to return over a very large number of plays. It does not predict the result of one spin or one session.
What does volatility mean in slots?
Volatility describes how a slot distributes its payouts. Low-volatility slots tend to pay smaller amounts more frequently, while high-volatility slots tend to pay less often with the potential for larger wins.
What is the difference between a wild and a scatter?
A wild substitutes for specified regular symbols to help form winning combinations. A scatter usually pays or triggers a feature without needing to follow a standard payline.
What is the difference between a fixed and a progressive jackpot?
A fixed jackpot has a set value or multiplier under the paytable, while a progressive jackpot grows according to the game’s rules until it is won and reset.