Slot glossary A–Z
Every term you meet on a slot screen or in a bonus's terms, defined in plain English with examples and links to fuller guides.
By the Best Slots UK team. Last checked .
Slot glossary A–Z: every term explained with numbers
The slot glossary defines the words you meet on a game's info screen, in a casino's bonus terms and in UK gambling rules. Each entry opens with a one-sentence definition, then shows how the term works with a pound example, where you will see it, and which related terms are worth reading next.
Slot jargon matters because it hides money. A phrase like "96% RTP" or "10x wagering" sounds technical, yet it decides how much a session is likely to cost or how much you must stake before a bonus becomes withdrawable. Knowing what RTP and the house edge really measure is the quickest way to read any game or offer with a clear head.
Definitions here are written for the UK. Where a term means something slightly different abroad, or describes a feature that British players cannot use, the entry says so. Figures in the examples are illustrations chosen to make the arithmetic easy to follow; for a specific game, the numbers in its own help screen always take priority, because many slots exist in more than one RTP version and the casino decides which one it runs.
Glossary terms grouped by where you meet them
The cards are listed alphabetically, but most terms fall into one of six families. Starting with the right family makes the rest easier to follow.
| Family | Example terms | Where you see them |
|---|---|---|
| Game maths | RTP, variance, hit frequency, house edge | The game's help or info screen |
| Reel mechanics | Paylines, ways to win, Megaways, cluster pays | Paytable and game rules |
| Symbols and features | Wild, scatter, multiplier, retrigger | Paytable and feature description |
| Jackpots | Progressive, must-drop, fixed jackpot | Jackpot meters and game rules |
| Bonus terms | Wagering requirement, spin value, max bet rule, no wagering | A casino's promotion terms |
| UK rules and safer gambling | Stake limit, spin speed, reality check, GAMSTOP | Account settings and UK regulation |
Terms A–Z
Terms that change what a slot session costs
A handful of terms do most of the work in deciding your results. RTP and house edge are two sides of the same number: a slot with a 96% return to player has a 4% house edge. Play 300 spins at £1 and you have staked £300, so the theoretical cost is £12. That figure is an average over millions of spins, which is why variance matters too. A high-variance game can leave you £60 down or £200 up over those same 300 spins, while a low-variance one tends to stay closer to the average.
Hit frequency adds another layer. If a game shows a hit rate of 25%, roughly one spin in four returns something, but many of those wins are smaller than the stake. A 20p return on a 50p spin is a loss of 30p, and UK rules stop the game celebrating it as a win. The glossary entry on losses disguised as wins explains why that rule exists.
Bonus terms follow the same logic. Under the 10x wagering cap that applies from 19 January 2026, a £20 bonus needs at most £200 of qualifying bets before it can be withdrawn. The wagering requirement entry works through examples with different game weightings and expiry periods.
UK rule terms you will see on every slot
Several glossary entries describe things that are banned or limited for players in Great Britain. They are included because overseas videos, streams and reviews still mention them, and it helps to know why a UK version of the same game behaves differently.
- Autoplay, turbo spin and slam stop have been switched off on UK slots since 31 October 2021.
- Spin speed must be at least 2.5 seconds per spin.
- Stake limit means £5 per spin at 25 and over, £2 per spin for players aged 18 to 24.
- Net position display shows how much you are up or down in the current session at all times.
- Bonus buy is not offered to players in Great Britain.
- Demo mode is only available once the casino has verified your age.
These rules exist to slow play down and keep the real cost visible. Removing autoplay means every spin is a separate decision, and the net position display stops a run of small returns from hiding a steady loss.
How to use the glossary alongside a slot review
The glossary works best next to a real game. Try this the next time you look at a slot:
- Open the game's info screen, or the facts box at the top of its review on our slot reviews pages.
- Note the RTP, volatility, layout and max win.
- Look up any term you are unsure of in the cards below.
- Read the related terms linked at the end of each entry to see how they fit together.
- Compare two games on the same figures before choosing a stake.
Frequently asked questions
What is the difference between RTP and house edge?
They describe the same thing from opposite sides. RTP, or return to player, is the share of all money staked on a slot that the game is designed to pay back over a very long period. The house edge is what is left for the casino. A 96% RTP slot therefore has a 4% house edge, meaning a theoretical cost of £4 for every £100 staked. Neither figure predicts a single session, because results swing widely in the short term. The house edge entry shows how the gap adds up across different stake sizes.
Is volatility the same as variance?
Yes, in slot terms the two words are used interchangeably. Both describe how a game's returns are spread out. A low-volatility slot pays smaller amounts more often, so a balance tends to move gently. A high-volatility slot pays less often but can produce larger wins, so balances swing harder and long dry spells are normal. Developers usually show volatility as a label or a scale on the info screen rather than a precise number. The variance entry explains how to match it to your budget and session length.
Why does the glossary include terms that are banned in the UK?
Because players still meet them. Videos, streams and reviews written for other countries talk about autoplay, turbo spins and bonus buys as if they were normal, and some slots offer them outside Great Britain. Knowing what they are helps you understand why the UK version of a game behaves differently, and why a feature you saw online is missing from your casino. Each entry states the British rule and the date it came in. The guide to UK slot rules brings all of them together with a timeline.
What does max win mean on a slot?
Max win is the largest amount a single spin or bonus round can pay, usually shown as a multiple of your stake. A 5,000x max win on a 20p spin is £1,000. Once a feature reaches that figure, most games end the round and pay the capped amount, even if more spins remain. Very few sessions come anywhere near the top prize, which is often a once-in-millions outcome. The max win entry explains how to read the figure, and why a large cap usually signals high volatility rather than better odds.
How is the glossary different from the slot guides?
The glossary defines one term per page, briefly and with a single worked example, so you can check a word quickly while reading a review or a promotion. The guides go further on a whole topic, such as how bonuses work or how to set a session budget, and use several terms together. Most glossary entries link to the guide that covers the same ground in more depth. If you are new to slots, reading the slot guides first and dipping into the glossary when a term is unclear is a sensible order.
Are the bonus terms in the glossary the same at every casino?
The definitions are the same, but the numbers vary by casino and offer. Wagering requirements, spin values, expiry periods and maximum bet rules are all set in each promotion's own terms. What is fixed is the legal ceiling: from 19 January 2026, wagering on any bonus is capped at 10x, and promotions that mix gambling products, such as betting on sport to unlock casino spins, are banned. Always read the specific terms before opting in. The no wagering entry explains the simplest type of offer.
Where do the safer gambling terms fit in?
They have their own family in the glossary and carry no promotion of any kind. Entries such as deposit limit, time-out, reality check and self-exclusion explain what each tool does, how long it lasts and where to find it in a casino account. GAMSTOP covers national online self-exclusion, which blocks every UKGC-licensed site at once for six months, one year or five years. If you are worried about your gambling, the free National Gambling Helpline on 0808 8020 133 is open 24 hours a day.