Video Slots Features and Bonus Rounds

Video slots are perhaps the easiest online casino games to learn and play. All you need to do is select the size of your bet per spin, hit the ‘start’ button’ and away you go – the slot does the rest of the hard work for you.

The RNG kicks into play, the animations come alive, and the slot technology that governs the bonus rounds, combination wins, and slot features automatically display and pay winning multipliers. Yet despite the slots doing all the hard work for you, not knowing what, where, when, and why the slot is paying out is not enough for some players, and rightly so.

To truly understand which online slots to choose, recognising the technology used will help you become a more educated player. And it just so happens to be exactly the reason we created this guide. Below we will cover some of the most confusing slot tech being used today by the big guns such as BTG, Yggdrasil, Pragmatic Play, Microgaming, and co, so when you choose a video slot, you know exactly which mechanics are in play!

Ways-to-Win – (Adjacent Reels No Paylines)

Probably the most misunderstood iGaming tech is video slots with no pay lines. The first software provider recorded to divert away from using pay lines is Microgaming. It was the now defunct Lord of the Rings Jackpot slot that would employ the brand-new 243-ways-to-win no pay line features. These slots kept the 5x3 reel format but used a concept called ‘adjacent reels’ to determine a combination win, and it is actually very easy to understand.

  • For a combination to count as win, the first symbol must be on reel 1
  • Each subsequent symbol must line up on consecutive adjacent reels
  • 2-symbol win must have alike symbols on reels 1-2.
  • 3-symbol combination wins must have alike symbols on reels 1-2-3
  • The same flow applies to 4-, 5-, and 6-symbol combination wins
  • It doesn't matter where the symbol is on its respective reel (top-middle-bottom

From the no-pay-line 243-ways-to-win slots we now have…

  • 1024-ways-to-win: Once the 243-ways-to-win slot concept became popular, developers soon adopted the 1024-ways-to-win concept which uses 5x4 reels to fit in more ways to win.
  • 4096-ways-to-win: By adding a 6th reel and using a 6x4 reel grid developers could create 2000 ways-to-win including the infamous 4,096 ways-to-win slots, for example, Playtech’s Buffalo Blitz virtual and live slots.
  • 117,649-ways to win: Megaways slots use the same no pay line tech with the ‘adjacent reels’ rules to churn out combinations wins but with a little twist…


Even though BTG patented ‘Megaways’, the developer did not invent the no pay lines concept – we still owe that honour to Microgaming. However, what BTG did do is move the goalposts for the ‘ways-to-win’ concept using ‘Shape-Shifting Reels’. You will see some Megaways articles refer to these slots as using a 6x7 grid system but that isn’t strictly true, and here is why…

  • On any given spin an individual reel can produce 2, 3, 4, 5, 6, or 7 symbols
  • A spin could produce 2-4-7-6-4-6 symbols in 6 reels or 7-7-7-7-7-7 symbols
  • The number of Megaways changes each spin depending on the number of symbols in view
  • For 117,649-ways to win, all 6 reels must show 7 symbols on each i.e., 7-7-7-7-7-7

Now you know why Megaways slots can produce such a large number of ways-to-win, and why this type of slot earns itself the ‘shape-shifting reels’ nickname. It is also worth noting that you will also come across different types of Megaways slots like Tiki Infinity Reels X Megaways which shape-shifts between 2 and 5 symbols, but has unlimited Megaways and here is why…

Infinity Reels

At the time of this writing, the ‘Infinity Reels’ feature was still in its infancy with only a handful titles, and we expect to see many more over the coming years. As the name suggests, the slot can produce an infinite number of reels. For example, let’s take Tiki Infinity Reels X Megaways starts with 3 reels.

  • If the 1st spin produces a 3-symbol win, the slot adds a new 4th reel
  • Only the newly added reel will spin
  • If the 3-symbol win extends to a 4-symbol win, the slot adds a new 5th reel
  • Only the newly added reel will spin
  • If the 4-symbol win extends to a 5-symbol win, the slot adds a new 6th reel

You get the picture! This process can continue forever creating ‘Infinite Reels’, which also means there is no limit to the number of Megaways.

Cluster Wins a.k.a. Cluster Pays

‘Cluster Pays’ or ‘Cluster Wins’ slots are incredibly fun. Gemix 2 is one of them. These slots park the bus with ‘Pay Lines’ and the ‘Adjacent Reels’ concepts, and instead use a ‘Tetris’ style way to form combinations wins. Except rather than using the term combination, the phrase ‘clusters’ is used.

  • To form a cluster symbols, need to be on adjacent positions (not reels)
  • Symbols must be above, below, left, right, or diagonally
  • Clusters can create squares, rectangles, and other shapes
  • Clusters usually need a minimum of 5 symbols
  • Some clusters can group together 25 symbols
  • Clusters can form anywhere on the face of slot

Rolling Reels or Cascading Reels

Most Megaways slots, almost all cluster pays, and some pay line as well as ways-to-win slots use the cascading reels feature also known as rolling reels on Microgaming slots.

  • The slot removes Symbols in a winning combination off the reels
  • New symbols drop in to fill the empty positions
  • Now any new combinations created payout
  • New wins are added to your current winnings from the spin
  • Cascading reels continue until there are no more new wins

Win Both Ways

If a slot pays both ways (like Starburst for example), then it can pay from left-to-right or right-to-left. Take, for instance, the ‘adjacent reels’ concept for no pay lines slots which is also used for pay line slots. The same rules apply for wins from right-to-left (the first symbol must start on reel 1) – and conversely, the first symbol must start on reel 5 and run across consecutive reels for the ‘Both Ways’ feature to work.

  • Combination wins pay left-to-right (Reels 1-2-3-4-5)
  • Combination wins pay right-to-left (Reels 5-4-3-2-1)

Rounding Up Slot Tech

In this video slot technology guide, we explained some of the most confusing components used in modern day online and mobile slot gameplay. The concepts explained will give newbie slot players a solid grounding and help you understand the mechanics behind the technological terms used to describe each video slot’s main functionality. For further reading we also suggest checking out:



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