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On this page
Slot guides on this page cover six of the best-known online slots in the UK, using figures from each game provider’s own website rather than third-party sites. For every game we give the published RTP and volatility (or say “not published”), explain how the features work, state the provider’s max win where it gives one, and list any verified casino offer that gives spins on it. UK stake limits apply to all of them: £5 per spin for 25+ and £2 for 18–24-year-olds.
Casino offers we list
- 1
Midnite New customers Editor's pick
Deposit & play £20, get 100 Free Spins on Big Bass Splash
New customers. Code BETGETCASINO. Deposit £20+ and stake £20 on eligible games within 14 days of sign-up. 100 Free Spins at 10p on Big Bass Splash, expire 7 days after crediting. Free stake not returned. Restart the game to activate spins.
Promo code:
BETGETCASINO· Spins have a fixed 10p value and a clear 7-day window.Full T&Cs
New Midnite customers 18+. Sign up with code BETGETCASINO, deposit at least £20 and wager £20 or more on eligible games (Cops 'N' Robbers Grand Chance, Big Bass Splash, Big Bass Secrets of the Golden Lake, KKC Even Bigger Bananas, Fishing Frenzy Big Catch) within 14 days. Reward: 100 Free Spins on Big Bass Splash at 10p per spin (£10 total value); non-withdrawable, expire 7 days after crediting; free stake not returned with winnings. Restart the game to activate spins. Once per person/household/device/payment account; not with other promotions. Midnite Terms of Service and General Promotion T&Cs apply. Wagering on spin winnings is not stated on the offer page.
- 2
Unibet New customers
Stake £30 on slots, get 300 Free Spins on Big Bass Splash (10x wagering)
New GB customers. Opt in at registration. Deposit £30+ by debit card or instant bank transfer and stake £30 on slots within 7 days. 300 x 10p spins on Big Bass Splash; use within 48 hours. Winnings wagered 10x within 30 days. Credit card, Apple Pay, PayPal, Paysafecard, Skrill and Neteller excluded. Game contributions vary.
Wagering on spin winnings is within the 10x cap.
Full T&Cs
New customers 18+ located in Great Britain. Opt in at registration. Deposit £30+ via debit card or instant bank transfer only and stake £30 on slots within 7 days of registration. 300 Free Spins at £0.10 on Big Bass Splash, credited after qualifying (up to 72 hours). Spins must be used within 48 hours. Winnings must be wagered 10x on slots within 30 days before becoming withdrawable; slots contribute 100%, table games 10%, some games blocked; jackpot contributions do not count. Withdrawing cash before completing wagering cancels bonus funds. Not eligible with credit cards, Apple Pay, PayPal, Paysafecard, Skrill or Neteller. Unibet Promotional and Standard Terms apply.
- Debit card
- Instant bank transfer
New customers. Choose bonus at sign-up and deposit within 7 days. 100% up to £25 Casino Bonus. Wager bonus 10x on slots within 3 days. Max bonus winnings £1,000; bonus itself not withdrawable. Excluded games apply. Skrill and Neteller deposits excluded.
Wagering is at the 10x legal cap.
Full T&Cs
Choose the Casino Welcome Bonus at sign-up and deposit within 7 days for a 100% bonus up to £25 in your Casino Bonus balance. Wager the bonus 10x on slots within 3 days to convert to withdrawable cash. Max bonus winnings £1,000; bonus amount non-redeemable. Some games excluded. Withdrawal before completing wagering forfeits bonus and winnings. Cash used before bonus. Skrill or Neteller deposits not eligible. Not with other promotions. 10bet general T&Cs and Promotion Terms apply.
New customers only unless stated. 18+. Offers can change or be withdrawn by the operator at any time; read the full terms on the casino’s own site before you deposit.
Our slot guides
| Slot | Provider | Published RTP | Volatility | Max win (provider) | Verified spins offer |
|---|---|---|---|---|---|
| Big Bass Splash | Pragmatic Play | 96.71% | Not published | Not published | Midnite, Unibet |
| Gates of Olympus | Pragmatic Play | 96.50% | Not published | Not published | None verified |
| Sweet Bonanza | Pragmatic Play | 96.48% | Not published | Not published | None verified |
| Starburst | NetEnt | 96.08% | Not published as a category | 800 x bet | None verified |
| Book of Dead | Play’n GO | Not published | Not published | Not published | None verified |
| Fishin’ Frenzy | Blueprint Gaming | 90%–96.12% (several versions) | 5/5 on Blueprint’s scale | Not published | None verified |
Figures from provider game pages, last checked 21 October 2026. Casinos can run different RTP versions; the in-game help screen shows the one that applies.
What each guide covers
- Big Bass Splash: a fishing-themed game where wilds collect cash values in free spins, with retrigger multipliers of 2x, 3x and 10x.
- Gates of Olympus: a Greek mythology theme, symbols that pay anywhere, tumbling reels and multiplier symbols up to 500x.
- Sweet Bonanza: a fruit-and-confectionery theme with pay-anywhere tumbles and 2x–100x multipliers in free spins.
- Starburst: a 10-line gems game where expanding wilds trigger respins; NetEnt states an 800 x bet max payout.
- Book of Dead: an Ancient Egypt adventure with a randomly chosen expanding symbol in free spins.
- Fishin’ Frenzy: a 10-line fishing game whose free games use a fisherman symbol to collect fish values. Blueprint lists RTP versions from 90% to 96.12%.
How we check slot figures
We only use the game provider’s own page. If a provider doesn’t publish a figure there, we write “not published” rather than copy a number from a review or aggregator site. That’s why some cells above are blank on purpose. “Up to” figures, such as the top value of a multiplier symbol, aren’t the same as a game’s maximum win, and we don’t present them as if they were.
RTP, volatility and what they mean for you
RTP (return to player) is the long-run average share of stakes a game pays back across a very large number of spins. A 96% RTP means a theoretical cost of about £4 for every £100 staked, but a single session can end anywhere. Volatility describes how wins are spread: high-volatility games pay less often but in bigger amounts; low-volatility games pay smaller amounts more often. Neither figure makes a win more likely on your next spin. Our best paying slots page lists more provider-published RTPs, and the slots guide explains slot basics.
Free spins on these slots
Of the casino offers we’ve verified, only Big Bass Splash has spins attached: Midnite gives 100 spins at 10p after you deposit and wager £20 (code BETGETCASINO), and Unibet gives 300 spins at 10p after you deposit and stake £30 on slots, with winnings wagered 10x. 10bet’s deposit bonus (100% up to £25, 10x on slots within 3 days) can be used on eligible slots; check its excluded-games list. See free spins offers and no wagering bonuses.
UK rules that apply
- Slot stake limits. The most you can stake per online slot spin is £5 if you’re 25 or over and £2 if you’re 18–24 (Gambling Commission). These limits apply to online slots, not table games.
- 10x wagering cap. Since 19 January 2026, operators must not apply a wagering requirement of more than 10 times to bonus funds (LCCP SR Code 5.1.1). See UK wagering cap rules.
- No credit cards. Since 14 April 2020, licensed operators can’t accept credit card payments for gambling, including through e-wallets funded by a credit card.
Staying in control
Slots are fast and continuous, which makes it easy to spend more than you meant to. Set a deposit limit before you play, decide in advance what you can afford to lose, and use reality checks and time-outs. Never chase losses. If you want a break from all UK-licensed gambling sites at once, GamStop is free and lets you self-exclude for 6 months, 1 year or 5 years. The National Gambling Helpline (0808 8020 133) is free, confidential and open 24 hours. More help: responsible gambling.
Frequently asked questions
Where do your slot RTPs come from? Only from the game provider’s own website, last checked 21 October 2026.
Which of these slots has the highest RTP? Of the published figures, Big Bass Splash at 96.71% (Pragmatic Play). The differences are small next to normal session swings.
Why does Book of Dead say “not published”? Play’n GO’s game page doesn’t list RTP, volatility or max win, so we don’t quote third-party figures.
What’s the most I can stake on a slot in the UK? £5 per spin if you’re 25 or over, £2 if you’re 18–24.
Which slots have free spins offers? Among our verified offers, only Big Bass Splash (Midnite and Unibet).
Sources checked
Last checked 21 October 2026. Where we couldn’t confirm a fact on an official source, we’ve said so rather than guess.
- Pragmatic Play – Big Bass Splash
- Pragmatic Play – Gates of Olympus
- Pragmatic Play – Sweet Bonanza
- NetEnt – Starburst
- Play’n GO – Book of Dead
- Blueprint Gaming – Fishin’ Frenzy
- Midnite – UK casino welcome offer
- Unibet – Free spins welcome offer
- Gambling Commission – Online slots stake limit guidance
More from our casino section
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18+ only. Please gamble responsibly. For free, confidential support visit BeGambleAware.org or call the National Gambling Helpline on 0808 8020 133.