Key takeaways
- 20 terms, A to Z.
- Notes on what is not available in Britain.
- Links to fuller guides.
A to Z
- Autoplay
- Automatic spins. Not permitted in Britain.
- Base game
- Ordinary spins outside features.
- Bonus buy
- Paying to start a feature. Not offered in Britain.
- Bonus spins
- Spins given by a casino as an offer.
- Feature spins
- Free spins triggered inside a slot.
- House edge
- 100% minus RTP.
- Max win
- Largest win on one spin, as a multiple of stake.
- Multiplier
- A value that multiplies a win.
- Payline
- A path on which matching symbols pay.
- Pays anywhere
- Wins from enough matching symbols anywhere.
- Paytable
- The in-game list of symbol values and rules.
- RNG
- Random number generator.
- RTP
- Return to player.
- Scatter
- A symbol that triggers from any position.
- Spin value
- The stake of one spin.
- Stake
- The amount bet on a spin.
- Tumble
- Winners removed and replaced.
- Volatility
- How a slot spreads its payouts.
- Wagering
- Stakes needed before a bonus becomes cash; 10x at most.
- Wild
- A substitute symbol.
Five to learn first
RTP, volatility, max win, stake and spin value. See RTP, volatility and spin value.
More guides: How online slots work, Slot RTP explained and Slot volatility explained.
Slot figures are developers' published defaults, each confirmed against two sources; your casino may run a lower RTP. Offer terms dated 5 October 2026. How we check. 18+. Free help: 0808 8020 133 or safer gambling.
Frequently asked questions
What does RTP mean?
Return to player.
What are bonus spins?
Spins given by a casino.
What is a tumble?
Winners removed and replaced.
What is spin value?
The stake of one spin.