Mental Slot Review

Based on our expert’s review. Reviewed by
Nolimit City Slots
Review by
Chris Taylor
Updated: 30/11/2023
Review by
Chris Taylor
Updated: 30/11/2023

Feeling brave? You’ll need to be. A supremely creepy asylum is the setting for the decidedly chilly Mental slot, a 5 reel game from Nolimit City. Like most slots from this developer, expect immersive sound and visuals and plenty of complex gameplay. You’ll find plenty in the way of extras here including split symbols, multipliers of up to 9,999x, transforming symbols and 3 different free spins features. As you might imagine given its theme, it is volatile in the extreme. Maximum payouts clock in at an enormous 66,666 x stake. Find out more in our detailed Mental review.

Max Win
66,666 x bet
T&Cs Apply

18+. New customers. Opt-in required. 20 Bonus Spins on “Sahara Riches Cash Collect” at 10p per spin and 100% Deposit Bonus up to £100 on first deposit (payment method and play restrictions apply). Min. deposit £10. 30x wagering for Bonus Spins and Deposit Bonus (game weighting applies). Max. £5/spin or £0.50/line. 30 days expiry. Please gamble responsibly • #ad

Nolimit City
Type of Slot
Video Slot
Mental Asylum
108-1 billion+
Stakes Range
20p to £70
Bonus Features
Yes (8)
Free Spins/Multiplier
Max Win
66,666 x
Very High (Extreme)

Mental Demo

18plus uk-gambling-commission online-slot-co-uk-logo agechecked-verification-provider
T&Cs Apply 18+. New customers. Opt-in required. 20 Bonus Spins on “Sahara Riches Cash Collect” at 10p per spin and 100% Deposit Bonus up to £100 on first deposit (payment method and play restrictions apply). Min. deposit £10. 30x wagering for Bonus Spins and Deposit Bonus (game weighting applies). Max. £5/spin or £0.50/line. 30 days expiry. Please gamble responsibly • #ad
18plus uk-gambling-commission online-slot-co-uk-logo agechecked-verification-provider
T&Cs Apply 18+. New customers. Opt-in required. 20 Bonus Spins on “Sahara Riches Cash Collect” at 10p per spin and 100% Deposit Bonus up to £100 on first deposit (payment method and play restrictions apply). Min. deposit £10. 30x wagering for Bonus Spins and Deposit Bonus (game weighting applies). Max. £5/spin or £0.50/line. 30 days expiry. Please gamble responsibly • #ad

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Mental Slot RTP, Details and Wager Limits

Reels/Paylines: 5 reels + 1 billion+ ways to win

Stakes Range: 20p to £70 per spin

RTP: 96.08%

Max Win: 66,666 x stake per spin

The Mental slot is played using 5 reels and 108 ways to win. With the reel format being 2x3x3x3x2, it’s the same as Nolimit City’s popular Tombstone game. With the various mechanics in play, over 1 billion ways to win are possible.

Create winning combinations by landing 3, 4 or 5 matching symbols wilds on adjacent reels from left to right, starting from the leftmost reel.

Bet levels range from 20p to £70 per spin. Click on the $ icon below the reels to see all available stakes. Paytable amounts are displayed in cash, relative to your total stake. In some countries, you’ll find a Turbo Mode for faster spin speed and an Autoplay facility which allows up to 1,000 auto spins.

The Mental RTP is 96.08% which is about average. Watch out as there is a 94.2% RTP version which may be on offer at some top UK slot sites. The 34.19% hit frequency rate means that on average, you’ll land a winning combination every 2.92 spins on average.

Nolimit City describes the Mental volatility as extreme so strap yourself in. This is proper 10 out of 10 stuff on the variance scale. The potential maximum win here is an enormous 66,666 x your total stake per spin.  This is known as ‘This is mental’. The max win lands once every 18 million spins on average.

Theme – enter a sinister asylum in search of an epiphany

Theme: Mental Asylum

High Value Symbol: Patient 1

Compatibility: Mobile, Tablet, Desktop


Many horror-themed slot games play things for laughs when it comes to design. The sound and visuals in the Mental slot really are quite disturbing. The setting is an insane asylum with flickering lights and sepia-tinged walls.

Think The Silence of the Lambs film. The soundtrack is a real chiller too. This is a slot that full of dark atmosphere. Nolimit City caused controversy and intrigue with their San Quentin slot (about the notorious prison) but Mental is even crazier and bound to split opinion.

On the reels, you’ll find 5 lower value symbols featuring skeleton hands, lungs, brains, hearts and eyes. They’re joined by 5 patient symbols (numbered 1, 2, 3, 4 and 5). The most lucrative is patient 1 in the Hannibal Lecter-style mask (patient 1) which pays 5 x your total stake if you land 5 in combination.

The skull symbol is the wild and substitutes for all symbols except the scorpion and spider scatters as well as the Dead Patient. Here’s a list of symbols and their payouts:

Symbol Payouts/Info
mental-slot-skeleton-hand-symbolSkeleton Hand 3, 4 or 5 = 0.1, 0.5 or 1 x stake
mental-slot-lungs-symbolLungs 3, 4 or 5 = 0.15, 0.55 or 1.05 x stake
mental-slot-heart-symbolHeart 3, 4 or 5 = 0.2, 0.6 or 1.1 x stake
mental-slot-brain-symbolBrain 3, 4 or 5 = 0.25, 0.65 or 1.15 x stake
mental-slot-eye-symbolEye 3, 4 or 5 = 0.3, 0.75 or 1.25 x stake
mental-slot-patient-5-symbolPatient 5 3, 4 or 5 = 0.4, 0.9 or 1.5 x stake
mental-slot-patient-4-symbolPatient 4 3, 4 or 5 = 0.45, 1 or 2 x stake
mental-slot-patient-3-symbolPatient 3 3, 4 or 5 = 0.5, 1.1 or 2.5 x stake
mental-slot-patient-2-symbolPatient 2 3, 4 or 5 = 0.6, 1.25 or 3.75 x stake
mental-slot-patient-1-symbolPatient 1 3, 4 or 5 = 0.75, 1.5 or 5 x stake
mental-slot-skull-wild-symbolSkull Wild Substitutes for all symbols above
mental-slot-scorpion-scatter-symbolScorpion Scatter 3 triggers Autopsy Free Spins
mental-slot-spider-scatter-symbolSpider Scatter 1/2 (+ 3 Scorpions) trigger Lobotomy/Mental Free Spins
mental-slot-dead-patient-symbolDead Patient 2 trigger Dead Patient feature

Mental Mobile mental-mobile-slot

Mental has been fully optimised for play on all devices including desktops, tablets and smartphones. Even though it comes with high definition graphics and animations, the most chilling experience will come on bigger screens in my opinion.

Mental Bonus Features

Few developers offer gameplay quite as complex as Nolimit City and the Mental slot is a case in point. This is a game that’s packed full of bonus features including transforming symbols, split symbols, multipliers and a trio of free spin features.

Fire Frames feature

On each spin between 1 and 13 reel positions can be randomly edged in flames. These positions will split and display 2 symbols instead of 1 and in turn, boost your chances of landing a big winning combination. This is known as the Fire Frames feature.

Dead Patient feature

9,999x Multipliers

You can trigger the Dead Patient feature by landing 2 Dead Patient symbols. Simply, 1 of the Patients will reveal a multiplier. Multipliers can be up to 9,999x (5x, 10x, 15x, 30x, 50x, 100x, 200x, 500x, 1,000x or 9,999x).

Enhancer Cells feature


Situated at the bottom of reels 2 and 4 are special symbol positions known as Enhancer Cells. Enhancer Cells become active if you land 4 or 6 Fire Frames respectively. Each Enhancer Cell will then reveal 1 of the following:

  • 1 of the 5 Patient symbols
  • Dead Patient symbol
  • Regular Wild
  • xWays symbol (reveals 3 of the same matching symbol apart from scorpion, spider or dead patients)
  • xSplit symbol (splits a symbol on each reel into 2 before turning into wilds)
  • xNudge Wild (shifts until it fills the reel. Each nudge increases a multiplier by 1x. Land more than one xNudge Wild and their values are added together)

Mental Transform feature


Trigger the Mental Transform feature by landing the spider symbol on reels 2 or 4. The Spider symbol then transforms into 1 of the following symbols:

  • xWays
  • xSplit
  • Dead Patient
  • Wild
  • Patient

Autopsy Free Spins feature

Land 3 Scorpion symbols on the same spin and you’ll trigger the Autopsy Free Spins feature with 8 free spins. Each scorpion in a Fire Frame adds 1 more free spin to that haul.

During this feature, up to 5 Fire Frames are added on each free spin. Once activated, they remain live for the rest of the round. You can upgrade the Autopsy Free Spins to the Lobotomy or Mental Free Spins features.

Lobotomy Free Spins feature

The Lobotomy Free Spins feature triggers by landing 3 Scorpions and a Spider on the same spin. Your reward is 9 free spins with 1 extra awarded for any Fire Frame triggers.

The Autonomy Free Spins extras are active in this round too. Spider symbols trigger the Mental Transform feature for each free spin and turn sticky.

Also boosting your chances here is the Dead Multiplier. Multipliers from Dead Symbols are collected in a count. These multipliers are added and then applied to the respective Patient symbols when they appear and the count reduced by 1.

Mental Free Spins feature


The top extra is the Mental Free Spins feature. This is triggered by landing 3 Scorpions and 2 Spiders on the same spin. You’ll then go on to play 10 free spins. As usual, Fire Frame scatters add to the free spins tally.

The Lobotomy Free Spins extras are active as well as a few new arrivals. Both Spider symbols are sticky and trigger the Mental Transform extras. Dead Multipliers do not decrease when they transfer to a Patient either. It can keep rising as new Dead Patient symbols are revealed.

Nolimit Bonus feature

Players in some territories will have the opportunity to buy a free spins feature. Known as the Nolimit Bonus feature, it’s not available to UK players. Anyway, each option will set you back between 80 and 1,000 x your total stake depending on which feature you plump for. Here are your options:

Feature Number of Free Spins Cost
Autopsy 8-11 80 x stake
Lobotomy 9-13 230 x stake
Mental 10-15 1,000 x stake
Lucky Dip (1 of the 3 above) 8-15 232 x stake

Mental Review Summary – as the name suggests, it’s truly mental

Based on our expert’s review. Reviewed by
Mental Slot

Mental is visually disturbing but pushes the boundaries of their xWays, xNudge and xSplit mechanics to a whole different level.

  • 66,666 x stake max wins
  • Unique theme + concept
  • Brilliant bonus features
  • Can feel complicated - try demo mode

The Mental slot really is an unusual game. The subject matter certainly won’t be to all tastes. The design is impressively done but it is genuinely disturbing. That’s no surprise considering it has features called Lobotomy and Autopsy Free Spins.

As mentioned above, Nolimit City will divide opinion with the mental asylum theme. When it comes to the gameplay, Mental is quite complicated. I recommend playing the demo above to get your head around the various bonus features.

That said, Mental is about the 3 free spins features. The best of them is the Mental Free Spins feature as Dead Multipliers can reach 9,999x and will not decrease when transferring to a Patient either.

As you’ll expect given the source material, it’s an extremely highly volatile slot. Nolimit City has pushed the boundaries of their xWays, xNudge and xSplit mechanics once again. The question is whether you’ll dare to visit this mental institute in search of 66,666 x stake max wins.

I think Mental delivers on many fronts. It’s truly disturbing, well designed and combines Nolimit City’s mechanics with new extras to offer something unique and appealing. If you want to play some of their other slots, the mining-themed Fire in the Hole and nuclear apocalypse-inspired xWays Hoarder xSplit would be my suggestions.

Want another terrifying adventure? Nolimit City’s Serial slot isn’t for the faint-hearted. Based on the Bodycam Butcher, a serial killer, offers lots of bonus features and 74,800 x bet max wins.

Mental FAQs

What is the Mental RTP?

The Mental RTP rate is 96.08%. The hit frequency rate delivers winning spins on around one third of spins on average. The variance is extreme (10/10).

What is the Mental max win?

The most you can potentially win from a Mental slot spin is 66,666 x your total stake. Your chances of winning big come from the Dead Multipliers which can reach up to 9,999x.

Are there any Mental free spins?

Yes, there are 3 free spins features which offer different modifiers and extras. The best is the Mental Free Spins feature which gives you Mental Transformations on each free spin and Dead Multipliers that don’t decrease.

Is there a Mental slot demo?

Yes, you can play the Mental free play version here at It’s available for a test drive on desktop, mobile and tablet devices too.

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