← mobile-casino-uk-guide.topUpdated 2026-08-11

Slot & Casino Glossary

The terms our reviews use, defined without marketing spin. Every definition describes how the mechanic actually behaves, including where it can work against you.

RTP (Return to Player)

The percentage of all wagered money a slot is designed to pay back over millions of spins. A 96% RTP means £96 returned per £100 staked across the long run — not per session. RTP is a theoretical average, never a promise about your next hour of play.

Volatility (Variance)

How a game distributes its payouts. Low volatility pays small amounts often; high volatility pays rarely but larger. Two slots can share an RTP and feel completely different because of it. Match volatility to your bankroll and session length, not to a jackpot fantasy.

Reels

The vertical columns that spin and stop to form a result. Most modern slots use five reels; classic machines use three. The reel count sets how many symbol combinations the maths engine can produce.

Paylines

The patterns across the reels on which matching symbols pay. Fixed-payline games stake all lines on every spin; "ways to win" games pay for any matching symbols on adjacent reels regardless of position.

Wild Symbol

A symbol that substitutes for others to complete a winning combination. Variants include expanding wilds (fill a whole reel), sticky wilds (hold across respins) and walking wilds (shift one reel per spin.)

Scatter Symbol

Pays or triggers a feature regardless of payline position — usually three or more anywhere on screen start free spins or a bonus round.

Multiplier

Multiplies the value of a win. Multipliers appear on symbols, on wilds, or as a progressive value that climbs during a feature. A 3x multiplier on a £10 win pays £30.

Free Spins

Spins awarded without deducting from your balance, either by a scatter trigger in-game or as a promotional bonus. Promotional free spins carry wagering requirements and often a maximum win cap — read those terms before opting in.

Bonus Round

A separate game mode with its own mechanics — pick-and-click prizes, wheels, hold-and-win respins — usually triggered by scatters. Bonus rounds carry most of a high-volatility slot’s win potential.

Megaways

A licensed mechanic where the number of symbols per reel changes each spin, producing a variable number of ways to win (commonly up to 117,649). Megaways titles typically run high volatility.

Max Win

The capped ceiling on what a single round can pay, expressed as a multiple of your stake (e.g. 5,000x). The cap matters: a game can advertise a huge multiplier that only the rarest feature outcome can reach.

Bet Range

The minimum and maximum stake per spin. A wide range lets the same game suit a £0.10 session and a £100 one; your stake should be a small fraction of the bankroll you set aside before playing.

Put the theory to work — 550% up to £7,000 + 450 Free Spins
Play at SpinPin

18+ · Advertising disclosure: we earn a commission from this operator · UKGC licensed · BeGambleAware.org · Terms apply

18+ only. Gambling should be entertainment, never income. Free help: BeGambleAware.org · GamCare · National Gambling Helpline 0808 8020 133 · GAMSTOP
Responsible Gambling · Privacy · Terms