Champion of the Underworld

Champion of the Underworld Slot Review

Slot Provider: Yggdrasil Gaming

RTP: 96% | Variance: High | Maximum Win: 10,000x

Our Score: 8.0

Play at Casumo Casino

WHY YOU CAN TRUST THIS REVIEW: The information and opinions on this page are the result of an comprehensive process of information gathering and live game testing by the gambling experts who work at Find out more here.

About Champion of the Underworld

Reviewed by:

Published Date: 13th October 2022

How We Review Slot Games

We test and rate all slot games across 5 criteria, assigning a score out of 10 for each and an overall score that is an average of the 5. To build an accurate assessment of each game we gather information from the supplier and play in real play or demo mode. Find out more.

Part of Yggdrasil’s ‘Underworld’ series, Champion of the Underworld, is a 4,096 payline slot with super-sized Gigablox symbols and a Wild Fight feature where Hades takes on monsters on the reels in a fight for supremacy and to lay down extra wilds. This is a super-volatile game that was unrelenting in testing but can no doubt unleash some spectacular wins where free spins, wilds and multipliers combine to dramatic affect.

Champion of the Underworld Game Information

  • Release Date: October 2022
  • RTP: 96.0%, 94.0%, 90.5%, 86.0%
  • Variance: High
  • Maximum Win: 10,000x
  • Progressive Jackpot: No
  • Reels: 6
  • Rows: 4
  • Paylines: 4,096
  • Minimum Stake: £0.20
  • Theme: Fantasy
  • Features: Wilds, Progressive Multipliers, Gigablox, Free Spins, Wild Fights

What We Liked

  • Epic atmosphere and great artwork
  • Gigablox on every spin
  • Top win of 10,000x
  • Chance for big multipliers in free spins

What We Didn't like

  • Very high variance and tough to break
  • Few features to keep you engaged

Champion of the Underworld Review Scores

  • Theme and Design 9
  • RTP and Variance 8
  • Maximum Win 7
  • Symbols and Paytable 8
  • Features and Gameplay 8

What Our Reviewer Says ...

"A fantastical battle slot with Gigablox, wilds and multipliers. Great atmosphere but a super-tough variance to break!"

Overall Score: 8.0

Theme & Design

Our Score 9

Champion of the Underworld is big on atmosphere. The game is set in a great arena in the underworld, with towering columns, fires burning and a crowd of ghostly souls watching on. They all cheer and clap, presumably rooting for their favourite monsters. It’s not a scary slot as such, but more cartoon horror with a dash of humour. In the background a pacey metal / hip hop soundtrack kicks in as soon as you spin the reels, which themselves roll on thunderously.

The general vibe is of sci fi films like Mad Max mixed with dark and supernatural horror. It comes together nicely into a coherent game.

RTP and Variance

Our Score 8

What is RTP?

RTP (Return to Player) refers to the amount a game will pay out in cash prizes expressed as a percentage of all the money wagered on that game. For example, a 96% RTP means a game will pay out £96 for every £100 wagered. This is an average number and will vary from one session to the next.  Read more here.

What is Variance?

Variance refers to how far a game will deviate from its RTP over time. High variance games deviate a lot and produce uneven win distributions and unexpected windfalls. Low variance games provide a more stable and even distribution of wins. Read more here.

Champion of the Underworld has four available RTP settings – 96.0%, 94.0%,  90.5% or 86.0%. You will find most UK slot sites run at the 96% or 94% setting. We checked three UK slot sites and this is what we found:

On this basis we recommend you play at either Casumo or Duelz Casino. The 96% optimum RTP level is average for an online slot. But it isn’t the highest paying Yggdrasil game – you can get a better return on Jokerizer at 98%, Beauty and the Beast at 97.1% and 9k Yeti and 97%.

What is for sure is that this is a volatile game – according to their own website Yggdrasil have it as ‘Super High’ volatility. So expect no mercy – you will be teased and tested for long periods but with its mix of multipliers and wilds it could also kick into a payout frenzy at any time!

Maximum Win

Our Score 7

What Is Maximum Win?

Maximum win refers to the maximum amount a player can win from one spin. It is expressed as a multiple of the stake. For example, where the maximum win is 100,000x, from a £1 stake, the maximum win would be £100,000.  

The maximum win in Champion of the Underworld is 10,000x. This is OK, but not fantastic. For better potential you could try Vikings Go Bezerk Reloaded at 25,000x or Hyper Burst at 12,800x. Check the table below for more comparible slots.

Explore Games With Similar RTP, Variance and Maximum Win

Like the numbers? Here are some more games you might want to try.

Slot SiteSupplierRTPVarianceTop Payout
Gladiator LegendsHacksaw Gaming96.31%High10,000xPlay Here
Hand of AnubisHacksaw Gaming96.24%High10,000xPlay Here
Gates of ValhallaPragmatic Play96.46%High10,000xPlay Here
Vikings Go Berzerk ReloadedYggdrasil Gaming96%High25,000xPlay Here
Vikings Go BerzerkYggdrasil Gaming96.1%Medium4,000xPlay Here

Symbols and Paytable

Our Score 8

Champion of the Underworld has an interesting pay table that includes super-sized symbols, or Gigablox, that can increase the win potential on each spin.

Let’s start with the basics though and this is a 6-reel game with 4 rows. To score wins you need to land three or more identical symbols on adjacent reels from left to right, starting with the left most reel. It doesn’t matter which row the symbols are on, just that they appear on adjacent reels.  This creates a classic 4,096 payline slot like Raging Rhino from WMS or Pink Elephants from Thunderkick.

But there is more to it because this is a Gigablox game. That means reels may merge on a spin and symbols may size-up to 2×2 or 4×4. If they do, and a Gigablock forms part of a win, it counts as 4 or 16 symbols.

Gigablox in Champion of the Underworld
Gigablox on Adjacent Reels

There are 4 low paying symbols made up of the card suits, diamonds, hearts, spades and clubs. The highest pay out here is 1.5x for six on a line. There are 4 premium monsters. These are in blue, green, purple and red. They pay out a max of 2x for 6 on a line. You will notice that symbol values are low but remember, they can be easily enhanced by the Gigablox feature and the many multipliers that come into play.

There are also Skull wilds that sub in for other symbols to complete winlines.

Features and Gameplay

Our Score 8

When you start spinning the first thing you’ll notice is that the reels merge on EVERY spin – so you always get Gigablox. Mostly 2×2 in size. The merging reels are surrounded in a kind of vaporous blue smoke which looks super cool and adds to the drama.  Every once in a while, two more reels will merge to give you 2 sets of Gigablox on one spin, or better still, four reels will merge to create 4×4 Gigablox which can set up some nice wins.

And when monsters form part of a win then they have a little animation that is cool to watch too.

You’ll soon settle into the rhythm of Champion of the Underworld. It’s not a hugely complex game. You spin the reels, you watch them merge, you wait for them to stop and on occasion a win is triggered … but rarely!

Aside from the basic pay mechanism, the other feature you are looking out for in the base game are the Wild Fights. Hades himself rises up in front of the reels in a fun animation and fights all the visible pay symbols. Each one he defeats is turned into a wild, even the Gigablox, to increase the odds of a win.

This Wild Fights feature, whilst good on paper, only appeared four times during our sessions, and only once did it result in a win and a small one at that.

Champion of the Underworld Wild Fight
A Rare Wild Fight Unlocked

But this is all part of the famed super high volatility Yggdrasil assign to this game. Perseverance is the key, right? And the really big wins are surely saved back for the free spins round.  That is true, but you need to land FIVE scatters for this – yes, that is FIVE. Not easy as we discovered, hitting 2, 3 or even 4 on many occasions, but always falling short. Five scatters gets you five spins, six gets you six and so on.

When you get there you have the option to gamble for more spins by picking a sword from a collection of 10. If you win, you earn more spins. If you lose, its back to the main game. Now, my advice would be not to gamble. Having spent hours trying to unlock free spins, better to enjoy it while you can … but it’s your choice!

The best part of free spins is – Hades shows up for a fight on every spin and he is not just earning you wilds now, he’s also adding multipliers and more spins to your total. You need to see 9 Wild Fight Wins to earn a 2x multiplier plus 2 more free spins. Then the totals go up like this:

  • 11 wins gets you a 3x multiplier plus 2 more free spins
  • 13 wins gets you a 5x multiplier plus 2 more free spins
  • 15 wins gets you a 10x multiplier plus 2 more free spins
  • 17 wins gets you a 25x multiplier plus 2 more free spins

It will take an extremely lucky streak to get here but if you are lucky enough to land yourself in free spins wonderland, the wins could suddenly come thick and fast.

The Final Verdict

When Yggdrasil tell you a game is super volatile they aren’t kidding. After 100s of spins on this slot we have still yet to unlock the free spins round and it remains just out of reach. All indications are that this is a classic high variance game and sooner or later it will break open to unleash an epic payout. Champion of the Underworld has great atmosphere which is good because it is needed to keep you engaged through all those uneventful spins. The artwork and animations are excellent. In my opinion it does fall a little short on features but high variance fans might not mind as they get their heads down and keep spinning in the quest to unlock that elusive free spins round.

Who Made Champion of the Underworld?

  • Name: Yggdrasil Gaming
  • Established: 2013
  • UK License: Remote 044137-R-322934-012
  • Total Games: 120 +
  • Known For: Vikings Go ... series, Gigablox series, wide range of themes and styles
  • Popular Slots: Vikings Go Bezerk, Jokerizer, 9k Yeti, Nitro Circus, Tuts Twister
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