Slots 101: Glossary of Key Slots Terms

Online Slots Glossary in Alphabetical Order

While slots may look simple on the surface, there's a lot more to them than meets the eye.

With lots of complex jargon and slot terminology being thrown around, you feel like you might need an Oxford dictionary to understand – especially if you're a new player. 

But as always, we're here to make things easier, separating your RTP from RNG, and explaining everything there is to know, so you can play with confidence.

Think of this as your slot's survival guide, ordered from A-Z and packed full of vital information you need to know in order to navigate this ever-changing industry.

We'll be updating this guide regularly to add any terms we might have missed, so bookmark this page and feel free refer back to it! (Don't worry, we won't be doing any pop quizzes to test your memory).

Full A-Z Glossary of Slots Terms

0-9

• 3-Reel: An online slot game with three reels, usually inspired by classic fruit machines in land-based casinos.
• 5-Reel: This is the standard for most online slots in 2026.

A

• Auto Play: Users can set a certain number of automatic spins according to their preferences. You can also set up win and loss limits. 
• Ante Bet: Typically increases your chances of landing special bonus symbols, i.e., scatters, for a cost.

B

• Base Game: This is the standard game, where you line up winning combinations (usually three or more symbols) and try to trigger bonus features.
• Bonus Buy: Similar to the ante bet, Bonus Buys lets you purchase direct access to bonus features. This feature is banned in Great Britain by the UKGC.  

C

• Cascades: Like the Avalanche feature, all winning symbols in a combination are removed from the grid, with new symbols ‘cascading' in to replace them. This continues until no more new wins are possible.
• Coins: Your balance may show up as coins rather than an actual monetary value.
• Coin Value: This is the value of each coin – this is more common in older slots like Book of Dead. 
• Cluster Pays: In these types of slots, any cluster of five or more matching symbols that are adjacent will award a winning combination.

D

• Demo: A free-to-play version of the real-money counterpart, so you can try the game without risk.
• Dream Drop: Relax Gaming‘s flagship progressive jackpot product, with five tiers: Rapid, Midi, Maxi, Major, and Mega.
• Drops & Wins: A promotional feature from Pragmatic Play that offers additional prizes when you bet real money on them. 

E

• Enhancers: Usually seen in Nolimit City games, Enhancers trigger bonus features or modifiers when filled with the relevant symbol.
• Expanding Wilds: These are usually wild symbols that expand to cover a whole reel, as seen in Starburst by NetEnt.

F

• Feature Buy: Similar to the Ante Bet and Bonus Buy features – letting you buy into a bonus for a set fee.
• Fixed Jackpot: A pre-determined jackpot amount you can win from a slot.
• Free Spins
  • Can be triggered in-game by landing three or more scatter symbols
  • Can also be claimed via casino promotions, as part of welcome bonuses.
• Fruit Machines: Another term for slots usually used in the UK, based on how classic slots were mainly made up of fruit symbols like cherries.

G

• GigaBlox: A signature mechanic from Yggdrasil Gaming that sees super-sized symbols form on the grid.
• Giant Symbols: Sometimes referred to as colossal symbols, these offer bigger payouts when used in combinations, similar to GigaBlox.

H

• Hammer: To “hammer” a slot is to play the same game repeatedly.
• Hit Frequency: The average number of winning combinations that occur. 
• Hold & Spin: Winning symbols are held in place with other positions respinning, continuing until no more wins are possible. 
• Hot Slots: A specific game that's paid out a lot, with a higher probability of paying out. The idea that slots can ‘run hot or cold' is a common superstition, though.

I

• Instant Win: Offering an immediate payout or fixed reward. 

J

• Jackpot: Offering a reward that is fixed or a progressive one that increases in value. 

K

N/A

L

• Lines: Another term for paylines, which dictate how winning combinations are formed. 

M

• Max Win: The maximum amount a slot game can pay out. 
• Megaways: A mechanic pioneered by Big Time Gaming, sometimes awarding up to 117,649 ways to win, thanks to dynamically-changing reels.
• Modifiers: Basically the same as a bonus feature, enhancing winning potential by adding multipliers, free spins, or wilds to gameplay.
• Multiplier: A feature that multiplies your winnings by a specific factor, sometimes increasing. 
• Mystery Symbols: These symbols transform into other symbols in the game once certain conditions are met, adding an element of intrigue. 

N

• Nudge: This modifier moves a reel or symbol a position either left or right to form winning combinations. 

O

• One-Arm Bandit: Another way of describing physical slot machines (ones with levers).

P

• Paylines: Decides the specific configuration of symbols needed to award a winning combination. 
• Paytable: The paytable displays the payouts, game rules, and information on how the bonus features work. 
• Pokies: A slang term used in New Zealand and Australia to describe slots, coming from poker.
• Progressive Jackpot: These types of jackpot slots have their total pooled across multiple slot sites, growing bigger every time a player wagers on them. 

Q

N/A

R

• Reels: The vertical columns in a slot game.
• Respins: Allows for an extra spin to trigger a bonus feature or land a winning combination.
• RNG: Stands for Random Number Generator, which randomly decides the result of a slot using a computer algorithm.  
• Rows: The horizontal lines in a slot game.
• Royal Symbol: Another way of describing the card suites used as paying symbols – you'll usually see A, K, Q, J, and 10.
• RTP: Short for Return to Player. This determines the theoretical payback percentage of a given slot. For example, if a slot has an 95.10% RTP, you can expect to win £95.10 when you stake £100, on average. 

S

• Scatters: These symbols usually trigger free spins or activate bonus features when you land a certain number of them (usually three or more).
• Stacked Symbols: These appear multiple times on a reel. 
• Sticky Wilds: These wilds remain in play during free spins rounds – often coming with multipliers.
• Symbols: These are just the icons you see on the slot, usually themed around the slot's overall theme. For example, Wild West slots usually have cowboy hats and guns. 

T

• Theme: This is what the slot is inspired by. There are lots of slot themes out there in 2026, from ancient Egypt to food and animals. 
• Turbo Mode: Offers ultra-fast gameplay and skips animations. It's banned in the UK. 

U

• UKGC: Short for the UK Gambling Commission, the governing body that oversees all gambling activity in the region. All sites recommended on Hideous Slots are licensed and regulated by them. 

V

• Video Slot: These games use animated reels rather than static ones.
• Volatility: Sometimes also known as variance, this determines how a slot game pays out over time.
  • Low Volatility: Offers small, more consistent payouts.
  • Medium Volatility: The best of both worlds, offering a medium level of frequency for wins with opportunities for bigger payouts.
  • High Volatility: Infrequent payouts, but the rewards are bigger when they do land. 
  • Extreme Volatility: Mostly from NLC, these slots are harder to bonus but have massive win potentials. 

W

• Wagering Requirements: These dictate how many times you need to stake your bonus funds or free spins before you can withdraw – typically attached to a casino's welcome bonus and other promotions. 
• Wilds: These symbols typically substitute for and replace all other symbols (except scatters) to complete winning combinations. You'll find many types of wilds, like sticky wilds, expanding wilds, stacked wilds, walking wilds, and many more!
• Win Both Ways: Slots traditionally pay from left-to-right as a set rule, but Win Both Ways also offers right-to-left wins, as seen in Starburst. 

X

• xMechanics: These are Nolimit City's trademark mechanics. We've broken down the most common ones below. 
  • xBet: NLC's version of a Bonus Bet or Ante Bet.
  • xBomb: Any wild xBomb in view will explode, blowing up all adjacent symbols except scatters, allowing new symbols to drop in.
  • xHole: Basically a black hole on the reels, xHole symbols suck in symbols, spit them out, and rearrange them into random clusters, first appearing in Kenneth Must Die.
  • xNudge: Seen in Deadwood RIP, if a wild is not centred on the reels, it will either nudge up or down, increasing the multiplier by x1 for each nudge. 
  • xRIP: In games like Tombstone RIP, if your spin doesn't pay out at least your initial bet, the win is reduced to zero. 
  • xSplit: Any xSplit symbol in view will split all symbols to the left of it in two, increasing the ways to win.
  • xWays: Increases the number of winning lines in an unlimited way, increasing the overall win potential. It's a major feature in games like Punk Rocker and San Quentin. 

Y

N/A

Z

N/A