| Provider | Playtech |
|---|---|
| RTP | 96.20% - Compare RTPs |
| Volatility | Medium |
| Reels | 5 |
| Paylines | 25 |
| Bet Range | £0.01 - £50.00 |
| Max Win | 10,000x |
| Features | Wilds, Scatters, Bonus Rounds |
Great Blue is a Playtech slot with an underwater theme built around whales, sharks, turtles and ocean scenery. Released in the mid-2000s, it became one of the most widely recognised Playtech titles and remains on many casino game menus today. It runs on 5 reels with 25 paylines, a high-volatility profile, and an RTP of 96.03%. The main draw is the free spins feature with shell picks that can lift both the spin count and the multiplier well above the entry-level values.
Great Blue RTP, Volatility and Game Info
| Developer | Playtech |
|---|---|
| Reels | 5 |
| Paylines | 25 |
| RTP | 96.03% |
| Volatility | High |
| Min Bet | £0.01 |
| Max Bet | £1,250 |
| Max Win | 10,000x line bet |
The 96.03% RTP is above average for a slot of this era. High volatility means the gap between wins can stretch across many spins, with the larger returns concentrated in the free spins round rather than distributed evenly through base game play. Great Blue suits players comfortable with session-level swings in exchange for bigger hits when the feature lands.
Paylines and Symbols
Great Blue uses 25 fixed paylines running left to right across the 5 reels. The high-value symbols are ocean creatures - a blue whale, shark, turtle, and stingray. Lower-value symbols use standard playing card icons (A, K, Q, J, 10, 9) rendered in the game's blue-and-green ocean palette.
Winning combinations pay when three or more matching symbols land on an active payline starting from reel 1. The killer whale is the highest-paying base game symbol. Five whale symbols on a line pays 2,500x the line bet at maximum multiplier, and five wild symbols pay 10,000x.
Wild Symbol - The Killer Whale
The killer whale functions as both a regular paying symbol and a wild. As a wild, it substitutes for all symbols except the scatter. The whale can appear stacked on any reel, meaning a full column of wilds is possible. When a wild completes or extends a winning combination, it doubles the payout for that line.
Stacked wilds across multiple reels simultaneously is where the largest base game wins come from. A spin with stacked wilds on reels 2, 3 and 4 covering most of the paylines produces a substantially different result from a standard base game spin, and the doubling multiplier applies to each line the wild covers.
Scatter Symbol and Feature Trigger
The oyster shell is the scatter. Three or more scatter symbols anywhere on the reels trigger the free spins feature, regardless of payline position. Scatter combinations also pay a multiplier of the total bet: 2 scatters pay 2x, 3 pay 5x, 4 pay 20x, and 5 pay 500x the total bet.
These scatter pays are added to any line wins on the same spin, so a scatter trigger spin that also has a strong payline result can produce a meaningful combined payout before the free spins even begin.
Free Spins Feature and Shell Picks
Triggering the feature grants 8 free spins with a 2x multiplier applied to all wins. Before the spins begin, five oyster shells are displayed and you pick two. Each shell reveals either additional free spins or an increased multiplier. The picks determine your final free spins total and your final multiplier for the entire round.
The range of outcomes from the picks is wide. The minimum outcome is 8 spins at 2x. The maximum available through the picks is 33 free spins with a 15x multiplier. The probability of landing the highest combinations is low, but the shell pick mechanic means every trigger carries at least the possibility of a significantly enhanced round.
During free spins, the wild doubling mechanic remains active. A win covered by a stacked wild pays double under the wild rule, then the result is multiplied again by the round multiplier. At 15x with a doubled wild win, the effective multiplier on that specific line is 30x. Free spins can be retriggered - landing 3 or more scatters during the round awards a further 15 free spins at the same multiplier you are already playing with.
Base Game Rhythm
High volatility in Great Blue means the base game frequently produces sub-stake returns or nothing at all across many consecutive spins. The design does not soften this with frequent small wins or near-miss mechanics. Sequences of 30 or 40 spins with minimal returns before a single larger hit are within normal range for the game's variance profile.
The scatter pays provide some relief during dry base game stretches - two scatters appearing on a losing spin still pay 2x the total bet, which partially offsets the cost of that spin. Three or more scatters on a losing payline combination still deliver the feature trigger plus the scatter multiplier.
Theme and Design
Great Blue uses a classic underwater setting with deep ocean blues and greens throughout. The background depicts open water with light filtering down from the surface. The symbol art is clean and immediately readable on both desktop and smaller screens - an important quality given the game's age, as some older slots do not scale as well to mobile.
The ocean creatures are depicted without cartoonish exaggeration - the whale, shark, turtle, and stingray symbols are stylised but recognisable. The sound design uses ambient underwater tones with more prominent audio during wins and the feature round. Nothing about the presentation feels dated in a way that interferes with play, though the visual style is clearly from an earlier era of slot design.
Mobile
Great Blue runs in HTML5 and loads in a mobile browser without any additional software. The 5x3 grid scales well to portrait and landscape orientations. The payline structure and feature picks remain navigable on a phone screen, with the shell selection screen rendering clearly at smaller sizes. Performance on mobile is consistent with the desktop version.
Pros and Cons
Pros:
- 96.03% RTP is above average
- Shell picks give you agency over the free spins outcome range
- Up to 33 free spins with a 15x multiplier available
- Stacked wilds with doubling mechanic can produce strong base game hits
- Free spins retrigger available
- 5 scatters in base game pays 500x total bet
Cons:
- High volatility - long dry stretches are common
- No bonus buy option
- Visual design shows its age compared to modern releases
- Some casinos offer a reduced RTP variant - check the game info panel
Is Great Blue Worth Playing?
Great Blue has stayed on casino platforms for a long time for clear reasons. The shell pick mechanic adds a decision point that most contemporaries lacked, the stacked wilds create genuine base game volatility rather than just slow attrition, and the free spins ceiling at 33 spins with 15x means the feature can deliver a standout result rather than a predictable mid-range return.
The high variance profile is the main factor to weigh before playing. If you want frequent wins of modest size, Great Blue is not that game. If you are comfortable with a higher-variance session in exchange for larger potential outcomes from the feature, the mechanics hold up well for a game of its age. For more Playtech titles, see our Playtech slots page.
Who makes Great Blue?
Great Blue is made by Playtech, one of the largest slot developers in the industry. It is one of their most enduring ocean-themed titles.
What is the RTP of Great Blue?
Great Blue has an RTP of 96.03%. Some operators may offer a reduced RTP variant, so it is worth checking the game information panel at your casino to confirm which version you are playing.
How do you trigger the free spins in Great Blue?
Land three or more oyster shell scatter symbols anywhere on the reels to trigger the free spins feature. You start with 8 free spins at a 2x multiplier, then pick two shells from five to reveal additional spins or a higher multiplier - up to 33 spins with a 15x multiplier.
Can the free spins retrigger in Great Blue?
Yes. Landing three or more scatter symbols during the free spins round awards an additional 15 free spins at the same multiplier you are already playing with. The retrigger can occur multiple times.
What does the wild symbol do in Great Blue?
The killer whale is the wild symbol. It substitutes for all symbols except the scatter, can appear stacked on any reel, and doubles the payout for any winning combination it completes or extends.
Is Great Blue a high or low volatility slot?
Great Blue is a high-volatility slot. This means wins can be infrequent during the base game, with the larger returns typically concentrated in the free spins feature rather than spread evenly through regular play.
Where to Play Great Blue
These online casinos carry Playtech games including Great Blue. Read our Donbet review or browse all casino reviews.
Great Blue RTP and Variance
Great Blue has an RTP of 96.20%, which is above average. See our highest RTP slots for the best returning games. Medium volatility offers a balanced mix of win frequency and payout size.
At the minimum bet of £0.01 per spin, a £10 deposit gives you 1,000 spins with a statistical expected return of £9.62. Read our slot betting strategy guide for tips on managing your bankroll.
More Playtech Slots
If you enjoy Great Blue, try these other Playtech games available at the same casinos.
