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  1. Home/
  2. Rules/
  3. Great Blue

Online Casino Game Rules

Great Blue

5-Reel, 25-Line SlotLook For 5 Whales on Your Reels!

The goal of playing Great Blue online slot is to get a winning combination of symbols on the paylines. The slot also offers you the chance to win Free Games in the Seashell Bonus. The Win Multipliers in Free Games make Great Blue a popular choice for all types of casino player, including fans of online roulette and blackjack.

How to play:

  • Open the Click To Change menu to select a coin value for the Line Bet.
  • Click the Bet Per Line button to add coins to the Line Bet. Each click will increase the bet by another coin. A maximum of 10 coins can be bet on each payline. If you wish to bet more, go back and increase the coin value.
  • Set the number of paylines for the spin by actively clicking the Lines button. You can also choose paylines by clicking on the numbers 1-25 on the sides of the reels. Please be aware that clicking a number will also activate paylines below it (numerically).

Note: The Total Bet = Number of Paylines x Line Bet.

  • Press Spin to start the game when you have selected your bets and paylines. You can also spin the reels by pressing the Bet Max button. This will play the slot with 25 active paylines and 10 coins placed on the Line Bet.
  • Use the +/- buttons above Auto Start if you wish to set a number of spins to be played automatically. Click Auto Start when you have made your selections. Press Stop (replaces Auto Start) if you wish to revert back to manual play.

Note: Winning combinations will be highlighted on screen when the reels have come to rest. The total win amount will be shown in the Win Field. Winning Spins will also activate the Gamble Feature, which will be explained in greater detail in a later section.

Note: Payouts for all winning combinations are listed on the Paytable, which can be accessed by clicking the Info button.

Info Pages:

Click the Info button to launch the Info Pages, which includes the Paytable and information on special features. Use the arrows to flip through the pages. Press Back to exit and go back to the reels. Descriptions of the Info Pages are provided below:

Paytable – lists all the payouts for winning combinations. Press the Show Paylines button to load a graphic showing the positions of all 25 paylines as they appear on the reels.

Bonus – provides information on the rules and awarding of the Free Games Bonus.

Gamble – gives information on the rules of the Gamble Feature. Also displays the maximum double up limit for the game.


The objective of the main game is to land matching symbols on active paylines. These must work in chains (at least two or three symbols) from left to right starting on Reel 1. Only active paylines will pay out as Line Wins.

Please be aware that the Line Bet and Total Bet are different. The Line Bet is the amount bet on each active payline and is used to calculate a Line Win. The Total Bet is the total of all Line Bets (added up) and is used to calculate Scatter Wins.

About Payouts:

A full list of payouts for Great Blue is displayed on the Paytable Info Page. The payout figures are multiplied by the Line Bet (Line Win) or Total Bet (Scatter Win).

Only the combination with the highest value payout is awarded on each payline. Payouts from combinations on different paylines are added up (along with Scatter Wins) and paid as a total.

Wild Symbol:

Wild Symbols can stand in for any other symbol (except Bonus Scatter) to make the best possible Line Win on a payline.

Wild Symbols appear ‘stacked’ on the reels, meaning they can cover 1-3 positions on a reel.

A group of Wild Symbols will also award a unique payout if they form their own Line Win.

Scatter Symbol:

Scatter Symbols will pay out regardless of their position on the reels. Two or more Scatter Symbols in any position will award a payout (x Total Bet). Three or more Scatter Symbols will award a payout and the Free Games Bonus.

Free Games Bonus:

Press Click To Start when the Bonus has been awarded. A new screen will appear, prompting you to pick two of five Seashells. You are initially awarded 8 Free Games with a x2 Multiplier. Clicking the Seashells will reveal extra Free Games and/or an increase to the Multiplier.

  • You can win a maximum of 33 Free Games.
  • Your Win Multiplier can reach a maximum of x15.

The Free Games will begin playing automatically once the two Seashells have been opened. All payouts will be multiplied by the Win Multiplier achieved in the Seashell Bonus. Your total win for Free Games is displayed on the top right of the screen.  The remaining number of Free Games and Win Multiplier are shown on the top left of the screen.

Landing three or more Bonus Symbols on the reels during Free Games will award and extra 15 Free Games. The Multiplier will remain the same. This can be repeated infinitely.

Please note:

  • Free Games are played with the same bet specifications as the triggering spin.
  • The Gamble Feature is not available during Free Games.

When all Free Games have been played, the results will be shown on a summary screen. Press Continue to return to the main game.

Gamble Feature:

Any winning spin in the main game will activate the Gamble Feature. Press the Gamble button if you wish to enter the feature.

A new screen is launched, showing a deck of cards in the centre of the screen. You will be given the following options:

  • Red = bet that the next drawn card will be red (Hearts/Diamonds).
  • Black = bet that the next drawn card will be black (Spades/Clubs).
  • Collect = bank your winnings and exit the Gamble Feature.

Correctly guessing Red or Black will double your winnings. You will be able to Collect or try to double up your winnings again.

You can continue to double up (if successful) until the maximum double limit has been reached. This information is displayed on the Gamble Info Page.

An incorrect guess will forfeit all winnings and exit the Gamble Feature.

Please note:

  • The Gamble Feature is disabled during Auto Play and Free Games.

Return to Player:

The theoretical return to player (RTP) for Great Blue online slot is 96.03%.


The slot is played using the buttons described below:

Click To Change – opens a menu offering a range of coin values for the Line Bet.

+/- Auto Start – sets the number of Auto Spins. Press Auto Start to begin and Stop to exit.

Lines – activates another payline. You can play up to 25 paylines on each spin.

Bet Per Line – adds another coin to the Line Bet. You can bet up to 10 coins on each payline.

Bet Max – spins the reels with the maximum number of paylines and maximum Line Bet for your coin value.

Gamble – launches the Gamble Feature after a winning spin.

Spin – spins the reels with your chosen bet selections.

Casino Toolbar:

The upper and lower edges of the game screen hold general tools and displays. Descriptions are provided below:

Game Balance – shows a current display of your casino account balance.

Cashier – press to access banking options for your account. You can use the Cashier to make a withdrawal or deposit funds. It also provides options for checking transaction history.

Play for Real Money – click to play Great Blue slot for real money at William Hill Casino. This action will only be applicable if you are playing in Fun Mode.

Menu – select the tools icon to open a menu with the following options:

  • History = see the outcome of recent spins.
  • Options = adjust settings, including graphics and sounds.
  • Help = open this rules guide.
  • Online Support = contact William Hill Casino customer support online.

Close – press to end the current game session and return to the casino lobby page.

Quick Deposit – deposit funds into your account without opening the main banking menu. A selection of your preferred deposit methods can appear in a pop up window if your balance runs low.

Gadget Bar – open a gadget (if at least one is enabled) from the menu on the right of the screen. They can include mini casino games, which can be played alongside Great Blue. You may also find information on online casino bonus offers currently available from William Hill.

Note on Disconnections:

If you lose internet connection when playing a spin in the main game, the spin will be automatically completed. You can see the result by using the History Tool when you reconnect to the internet and load the game again. Only the next spin is completed if the game is being played using Auto Start. In all cases, winnings will be paid into your balance.

If you lose internet connection after being awarded the Free Games Bonus, you will be redirected back to Great Blue slot when you log into the casino again. Win Multipliers etc. will be restored and you can complete the Bonus from where you left off.

If you lose internet connection when playing the Gamble Feature, your winnings will be automatically banked and paid into your balance.

Note on Malfunctions:

All bets are voided in the event of a game malfunction. Your stake will be returned to you.

How to Play Online Casino Games at William Hill

We pride ourselves on offering a wide range of casino games online to cater to even the most demanding of online casino players. Our search function and simple menu tabs make it easy to find the exact type of casino games you are looking for at any time.

For fans of dealer games, we have an array of video poker, online blackjack titles and other casino card games. If you’re looking for the next big thing from the best game developers around right now then check our frequently updated new releases section. Or if you want to interact with professional casino game dealers in real-time at William Hill Ireland then take a look at our live casino lobby for a wide range of interactive table games.

Each casino game has its own set of rules which dictates how it will function and play. Understanding the rules of each game will help you have a better overall casino gaming experience. We’ve highlighted the rules of different casino game types below to help you understand more about how each one behaves.

Play the Best Video Slot Games

Slot games are one of the most popular types of online casino game and make up the largest selection of games here at William Hill. From classic fruit slots to the latest 3D slots, we work with all the best games providers to offer a large catalogue of high-quality slot titles for all our players to enjoy.

You can choose to keep things as simple or complex as you like with the huge range of slot games available to you. Also by using the demo mode, you can play some free casino games and try them out before you play for real money.

Understanding Video Slot Rules

Each slot game has its own unique set of rules because they often work in slightly different ways. It’s a good idea to click the info tab in any slot game to view the paytable and game notes. This will show you what each symbol is worth and how you go about landing a win on the reels. Some games might have expanding reels, wilds or different payline mechanics which means they change as you play them. You’ll also find some useful information on the bonus features of that specific game and how to trigger them.

Progressive Jackpots

If you want to go big or go home then our range of progressive jackpots will be just what you are looking for. All the current jackpot game totals are displayed for each game in the jackpot lobby. You can see the jackpot totals building up in real-time to help you decide which one to play next.

Progressive Jackpot Rules

It’s important to know what you need to do to trigger the jackpot feature in this type of slot for a shot at landing the big prize total. Checking the paytable info will tell you all you need to know about each individual progressive jackpot game. It should display the symbol combinations required to unlock the bonus rounds for the potential of larger wins.

Live Casino Games Online

For players who want to feel the thrill of playing table games, just like you would at a land-based casino, the live casino lobby is the place to go. Streamed live and direct onto your screen from our casino studios, you can interact with our professional game dealers in real-time. You’ll also be able to chat with other casino players, view the most recent game rounds and even choose your preferred camera angle.

Live Casino Game Rules

Live casino games online can be a bit more complex to play than other types of casino games. It’s a good idea to make sure you are familiar with the basics of how to play any of the table games before you pull up a virtual chair and join in.

As there are many variants for each live casino game, such as online roulette, blackjack and poker, each will have their own set of specific game rules.

If something seems unclear to you then send a message to the professional dealer who can clarify the aspects of that table game. Just remember that they can’t help you with any gaming tactics or strategies, that’s for you to research and plan beforehand.


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Play the Best Online Casino Games at William Hill

It’s easy to join in the fun at William Hill Ireland right now and start enjoying any of the exciting casino games mentioned above. Just follow our simple 2-step sign up form and enter your details when prompted to become our newest online casino player.

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