In Diamond Charge Extra, you can play for cash payouts of up to 5,000x your bet across the base game and bonus features. This game is based on classic slot machines and was released by Iron Dog Studio in March 2026. It includes a Hold & Win round with a Collect feature that gathers values from across the reels. To find out more about this slot, read our Diamond Charge Extra review below.



Diamond Charge Extra uses a basic 5x3 layout with just 5 fixed paylines. As you spin the reels, you need to match three, four, or five symbols on any payline to win. Bets range from £0.10 to £5.00 per spin.
The maximum win available is fairly average but still decent at 5,000x your bet, though the medium-high volatility can make good payouts infrequent.
Unfortunately, the theoretical RTP is only 91.44%. As the average RTP for slots is 96%, Diamond Charge Extra’s RTP is significantly lower than you might expect it to be.
You can play this slot at some of the leading UK online casinos. To help you choose where to try first, here is our list of the best slot sites:
Diamond Charge Extra features a more dazzling background than you’ll see in many other classic-themed slots.
Gems of different colours constantly zoom towards the screen, and multicoloured lights emanate from the centre. A large diamond floats above the reels, which looks exactly the same as the highest-paying symbol on the paytable.
Along with its vibrant visuals, this game also has an electronic soundtrack with an atmospheric, low-key feel.
On each spin, you’ll watch 15 symbols land across the reels. The standard symbols include royals, a sapphire, an emerald, a ruby, and a diamond. The diamond is the highest-paying standard symbol, worth 50x your bet for 5 on a payline.
But the Mega symbol is the top symbol overall: it awards 1,000x your bet. However, this prize is only available with help from Special Collector symbols.

Jack
3: 1x bet / 4: 3x bet / 5: 10x bet

Queen
3: 1x bet / 4: 3x bet / 5: 10x bet

King
3: 1x bet / 4: 3x bet / 5: 10x bet

Ace
3: 1x bet / 4: 3x bet / 5: 10x bet

Ruby
3: 2.50x bet / 4: 7.50x bet / 5: 25x bet

Sapphire
3: 2.50x bet / 4: 7.50x bet / 5: 25x bet

Emerald
3: 4x bet / 4: 10x bet / 5: 50x bet

Diamond
3: 4x bet / 4: 10x bet / 5: 50x bet

Wild
3: 4x bet / 4: 10x bet / 5: 75x bet
This slot game has been designed to run on desktop and mobile devices with the same high-quality performance. The visuals look as colourful and smooth on a phone or tablet as they do on a computer. Crucially, the game’s user-friendly controls make it easy to play on a mobile too.



Unlike some of the more basic classic-themed slots on the market, Diamond Charge Extra includes a variety of bonus features. Granted, they’re not the most original or diverse bonuses, but they still add depth.
Wild SymbolThe Wild symbol substitutes for all standard paying symbols but not the special symbols. It can appear on all reels.
If you land one Special Collector symbol and one Cash symbol on the reels at the same time, you’ll trigger the Collect feature. The Special Collector symbol will collect the total value of all Cash symbols on display.
Cash symbols include Special Bonus, Mini, Minor, Major, and Mega Prize symbols. Special Bonus symbols carry cash values of 1x - 10x your bet.
If a Special Collector symbol collects four or more Cash symbols, you’ll unlock the Hold & Win feature. At the start of the bonus round, you’ll win three respins, and paylines will be disabled.
During the Hold & Win feature, standard symbols won’t appear on the reels. Instead, expect to see just Cash, Special Collector, and Blank symbols.
Special Collector symbols are sticky and stay on the reels for the whole round. These symbols will collect all Cash symbol values that are currently visible.
Whenever a non-Blank symbol lands, the number of remaining respins will reset to three. The feature will end when you run out of respins or your total collected value hits 5,000x your bet.
If one or more Hold & Win symbols land on a spin, there is a random chance that more of them will be added to the reels. The Coin Shower feature will always add enough symbols to activate the Hold & Win feature.
This is a well-designed slot game with an eye-catching visual style and bonuses that can help you win some of the bigger payouts available. The Collect feature may instantly gather prize symbols from across the reels for you, and the Hold & Win round offers multiple respins.
However, the average theoretical RTP for Diamond Charge Extra is incredibly low at 91.44%. Slots generally only have an RTP so far below the industry average when they offer progressive jackpots. But the max possible win here is 5,000x your bet, which is decent yet certainly not unique.
Despite this issue, this game is still entertaining and a good effort overall.
Rating: 6.5
In this section, you’ll find answers to some of the most popular questions about Diamond Charge Extra.