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The Io slot machine from ELK Studios is a space-age game that packs plenty of lucrative features aimed at offering you an interstellar experience. It’s a 6 by 4 hitter that boasts of incredible winning potentials with a top prize of up to 5000x your stake thanks to a range of mouthwatering features such as bonus symbols, wild symbols, wild multiplier symbols, charged wilds, among other cool, unique features. Let’s take a closer look at the title Io casino slot machines features in our first-hand review.

Software Provider ELK Studios
Release Date June 2, 2020
Slot Variety Video Slot
Paylines/Winning Ways 4,096 to 262,144
Reels 6
Rows 4 to 8
Progressive Jackpot No
Jackpot Amount 5,000x your bet
Return to Player (RTP) 96.00%
Volatility High
Minimum/Maximum Bet 0.20/100

IO Info

RTP 96%
Software ELK Studios
Min Bet / Max Bet 0.2-100
Paylines 262144
Reels 6
Risk game No
Multiplier Yes
Bonus rounds Yes
Scatter symbol Yes
Wild symbol Yes
Free spins Yes

Io Slot Theme and Design

In case you didn’t know, ELK Studios’ Io slot game is named after Io, the innermost and third largest moon of Jupiter, the largest planet in our solar system. The title’s color pallet is composed of neon colors that give you a feel-good emotion as soon as you launch the title. There’s a gigantic purple planet in the background which resembles Jupiter, to give you an impression of a view that you’d have in a space station or space ship.

For the in-game symbols, however, the developer decided to mix things up with a couple of classic slot icons such as lucky 7s, diamonds, and clovers, on top of the theme-based blue stars and a bonus planet as the higher paying icons. The standard card game royals, on the other hand, make up for the low-value icons in the Io free slots game.

Io Slot: Rules and Rewards

The betting range here starts from a minimum of $0.20 and has 12 different bet levels going to a maximum of up to $100. With such a wide range of betting levels, a baseline and thousands of winning ways, there’s a potential of bagging up to 5,000x your initial bet, meaning that you can earn up to $500,000 cash.

IO slot wins

Coming with a high variance and a 96% RTP, you have a pretty good chance of breaking even and profiting from your gaming sessions. However, you have to brace yourself for a couple of dry spell rounds even when you play free Io slots.

Io Slot: Symbols, Features & Tips

Moving on to in-game symbols, the Io casino slot machines paytable is made up of 8 regulars split into high paying and low paying symbols. Every symbol in the game comes in a circular enclosure that makes them look like talismans. There are classic fruit machine icons such as lucky 7s, diamonds, clovers, and stars, for the higher paying icons, while J-A royals make up for the low paying icons.

The lucky sevens are the highest paying symbol here, while all the royal symbols reward the same. You’ll have to hit 3 to 6 matching symbols on a payline to win. The paytable is changeable, meaning that the symbol values change according to the bet amount. Below is a free Io slot highlight of the paytable (at a minimum stake):

  • Royal Symbols- every symbol pays 0.3x for six of a kind
  • The Blue star pays 0.9x for six of a kind
  • 4-leaf clover pays 1.2x for six of a kind
  • Pick diamond pays 2.4 for six of a kind
  • Luck 7 pays 10 x for six of a kind

To help cobble combinations together, Io online slot provides three wilds: Standard Wild, Forge Wild and the Charged Wild. Even though all of them have different roles, they can stand in for any regular pay symbol in the game. Let’s dig a little dipper.

Io Game Mechanic

In Io free slot machine, the gravity engine works actively on nearly all spins. You’ll see winning icons burst out, creating room for the residual symbols to tumble anywhere gravity takes them. Thus, rather than the usual spinning reels mechanic, when you play Io slot online, the title uses the avalanche mechanic.

Whenever you land a winning combination, the icons that formed the combination will vanish, and new symbols will drop from the top to fill the reels, with an extra row emerging on top of the standing ones. As long as you continue being a winner, the avalanche doesn’t stop, and in that case, the number of ways to win will increase from 4,096 up to 262,144 ways maximum, whereas the rows can double up to reach a maximum height of 8. Below is a breakdown of how the rows and winning ways it works:

  • 4 rows = 4,096 win lines
  • 5 rows = 15,625 win lines
  • 6 rows = 46,656 win lines
  • 7 rows = 117,649 win lines
  • 8 rows = 262,144 win lines

The Charge Wild Symbol

One of the Io special wild symbols is the Charged Wild, which has 4 lives. It can form four winning combinations before the icon vanishes. In essence, it loses a life for every winning cycle.

The Wild Forge Symbol

In the Io slot game, whenever the Forge Wild emerges, it will refill a space beneath it with a multiplier Wild symbol. The progressive value of the multiplier rises every time the Wild Forge feature is used (2x-20x). Just in case the Wild Forge drops to the bottom of the reels, it turns into a regular multiplier Wild symbol.

Laser Symbol

Be on the lookout for beams from 2 intersecting laser symbols. If this happens, the lasers and the regular symbols lying along the beam path will turn to the Wild. On the other hand, one laser beam will get rid of any symbol in its way to give you a fresh avalanche.

Bonus Game Feature

The Bonus Game feature is the main attraction of the title as it allows you to play free Io slot rounds without spending extra cash. The feature is triggered when you land three Bonus Scatter symbols anywhere on the same spin. On top of that, you’ll be awarded 7 free spins on a completely expanded set of reels having 8 rows and 262,144 ways to win. You can also retrigger the feature to get 14 free spins in total.

Bear in mind that all Wild Forge and Charged Wild symbols will drop left or right, but stay active for the next drop. This boosts your winning odds and gaining from multipliers.

Where to Play Io Casino Slot Machines?

Since ELK is already a popular casino software provider, we’ve already added this new title to our collection of free slots no download no registration. Given that the game doesn’t use the cookie-cutter spinning reels mechanic in favor of the innovative gravity mechanic, you’ll be better off if you play Io slot online for free first, before risking your cash. In that case, you can have a taste of the Io slot demo mode right here, on this page for free. No download, no registration, or filling of forms will be required whether you play on mobile or a desktop device.


Io is a breath of fresh air in the online slots gaming world particularly thanks to ELK Studio’s innovative gravity engine that allows for continuous symbol tumbles after each winning combo. Why don’t you play free Io slots on our site to enjoy some cutting-edge action?


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