Gentry Games’ 666 Bonanza is a classic-themed slot set in a cartoony version of the underworld. Line up devils, skulls, pitchforks, and BAR symbols to form winning combinations and grab up to 10,000x your bet. If you trigger the Wheel feature, you’ll get a chance to claim a guaranteed payout of at least 100x your stake, too. Keep reading our 666 Bonanza review to learn about the volatility, RTP, and more.


666 Bonanza features a classic layout based on traditional slot machines: a set of three reels with one payline. The goal on each spin is to line up three matching symbols and win a prize shown on the paytable. The paytable is shown next to the reels at all times, so you’ll always know the prize available for any combination.
At UK online casinos, you can bet from £0.10 to £5.00 per spin on this slot game. That’s in line with the latest Gambling Commission regulations. But players outside the UK may bet up to £100 instead.
666 Bonanza’s theoretical RTP is 96.37%, higher than the 96% average. As its volatility is in the medium-high range, the game can pay out on a regular basis.
This slot also can also award solid prizes: the maximum win available is 10,000x your bet. This top prize is higher than I expected it to be, as max wins are often lower in slots with such a simple design.
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As you might guess from the title, 666 Bonanza has an infernal theme. The background is filled with fire, and some of the symbols have a hellish influence. But it’s not scary or grotesque, the game has a fun and cartoony visual style.
The charming visuals make the fiery underworld look bright and colourful, even with a few ghoulish symbols on the paytable. The lively audio is a fantastic fit for the theme, too.
A key part of 666 Bonanza’s design is its old-school simplicity. The reels take up the right half of the screen, and the paytable is on the left. You can check the value of each winning combination whenever you like without needing to use the menu.
Some of the symbols are slot classics: you’ll see a ‘7’ and three types of BAR symbols. Any three BAR symbols together award the lowest prize of 10x your bet. The devil symbol pays the highest, 10,000x your bet.
You’ll see no Wild symbols in this game, but a ‘6’ may land on any reel at any time. This could help you unlock the Wheel feature, which I’ll explain later.
666 Bonanza has just two bonus features. Its main bonus is the Wheel feature, which gives you the chance to land a wide range of cash prizes. The Power bet is also available, which can help you unlock the Wheel feature.
To trigger the Wheel feature, you need to land a ‘6’ symbol on each reel at the same time. With a 666 in place on the payline, the Wheel feature will begin.
The wheel features 12 segments, each with a specific bet multiplier: prizes range from 100x to 10,000x your bet. You’re guaranteed to win a prize when the wheel stops spinning.
Power Bet is an optional bonus wager that increases your likelihood of triggering the Wheel feature. To do this, it adds more ‘6’ symbols to the reels and removes all non-BAR symbols.
However, Power Bet increases your stake by 50x. It also reduces the maximum possible win to 5,000x your bet — half the usual amount. Consider a bonus bet like this with care before you use it, and remember to play responsibly.
666 Bonanza puts an infernal spin on the classic slot design. With its simple setup, you should find the game easy to play even if it’s your first slot.
For me, the top prize of 10,000x the bet is 666 Bonanza’s major highlight. I assumed such a simple slot would have a low max win, and was surprised to see that wasn’t the case. This generous payout may help broaden the game’s appeal.
The Wheel feature is a decent addition and offers an extra chance to claim the biggest payout. It also guarantees a win, even if only a small one, which makes it more valuable.
However, some players may find the game’s simplicity off-putting. If you prefer slots with a large set of reels and lots of features, 666 Bonanza might not be for you.
Rating: 7.0
Here are a few of the most common questions about this slot: