Slot Symbols & Features Part 2: Reels and Respins

Just about every video slot review talks about reels to one degree or another. They have to. After all, mechanical slots were built on spinning reels more than 100 years ago. Today's video slots are merely a digital representation of that older technology. Indeed, if it were not for spinning reels, there would be no slots.

This post is the second in a three-part series explaining the fundamentals of video slot machines. If you haven't read the first post yet, we recommend you do so. It covers a number of different topics including video slot symbols, multipliers, and winning ways. This post will discuss everything you ever wanted to know about reels and re-spins.

How the Reels work

The first mechanical slot machines relied on paper reels powered by spring mechanisms. The reels had a variety of symbols printed on them - usually playing card symbols - to determine whether or not a spin produced a win. Those early paper reels were eventually replaced by plastic. Then came the age of video games. That is when mechanical games started to fade away. The reels on the video screen became digital representations of their mechanical counterparts.

Where the reels would stop on a mechanical game was a matter of chance based on the mechanics of the machine itself. Reels would spin, only to be stopped by a mechanical brake. Video slots are different. Because there are no mechanics involved, slot designers have to use some other mechanism.

The reels in video slots are controlled by random number generators (RNGs). Every symbol in a given game is assigned a number. During a spin, while you are seeing symbols flash by, the software behind the game is randomly choosing a number for each position on every reel. The chosen numbers determine which symbol appears when the reels stop.

Video slot software is also programmed to carry out certain actions depending on the numbers chosen. This is how they calculate line wins, scatter wins, multiplied wins, and so forth. It is also how software knows to trigger bonus play.

Spinning or Falling Symbols

Your average video slot game still relies on the traditional metaphor of spinning reels. Video graphics are programmed to replicate what you would see if you were playing an old, mechanical slot. This metaphor works very well for its intended purpose. However, designers use a different metaphor from time to time. That metaphor is falling symbols.

In a falling symbols scenario, reels do not spin when you click the 'spin' button. Instead, stacks of symbols fall from the top of the screen. This metaphor is known as 'cascading reels' or 'tumbling reels' in some games. Both terms more accurately describe what happens on the screen.

You may hit the 'spin' button to initiate action, but nothing is spinning; symbols are falling down instead. Unfortunately, game developers that choose to implement falling symbols still refer to their activation buttons as the 'spin' button.

Is there any advantage to one metaphor or the other? Mathematically speaking, no. RNGs are unaffected by the graphical representation of chosen numbers. Both metaphors may be advantageous in relation to game presentation.

For example, Realistic Games is known for their video slots that mimic first- and second-generation games of years gone by. The falling symbol metaphor wasn't in use back in the 70s and 80s, so you wouldn't expect to see a Realistic Games title with anything but spinning reels.

Reel configurations

There is one last thing to talk about before moving on to re-spins. That is reel configurations. Back in the days of the one-armed bandit, mechanical slot machines were 3-reel machines with a single pay line. This was known as a 3 x 1-reel configuration. The '3' speaks to the number of reels while the '1'speaks to the number of positions per reel.

Most video slots in this day and age follow the standard 5 x 3-reel configuration. The 5 x 4 configuration is becoming more popular with developers that prefer winning ways instead of standard pay lines. Then there are those games that utilize multiple sets of reels instead of just a single set.

For purposes of deciding on winning combinations, the majority of video slots require that said combinations begin at the far left position. This is to say that the first symbol in a winning combination falls on the very first reel at the left of the screen.

There are those games advertised as 'win in any direction' games. These are games that award wins for winning combinations that start at either the far left or far right positions. It matters not which edge a combination starts on as long as there are three like symbols on consecutive reels, on a single pay line.

The Respins Feature

Additional features that go above and beyond standard play are used as the hook to garner interest in a particular game. Developers look to add features that make a game more enjoyable without requiring casino operators to give away the store. One of those features is the re-spins feature.

Re-spinning is exactly what its name implies. However, taking advantage of this feature does not mean spinning all of the reels a second time. Doing so would amount to a standard spin anyway. Instead, you are choosing just one reel to spin. Why would you do that?

Let us say you have four like symbols on a single pay line. They appear on reels 1, 2, 4, and 5. It is great that you have four like symbols, but because reel 3 has a different symbol, you win nothing. The re-spins feature allows you to re-spin reel 3 in hopes of landing the right symbol and completing the combination.

The thing to understand about the re-spins feature is that it isn't free. You still have to place a wager. Thus, you are risking a bit more money on a spin that would otherwise have been totally lost. You have to gauge risk versus reward in this sort of scenario.

There are two other iterations of this feature you see in some games. These are:

• Nudge - This is a computer simulation of the old mechanical feature that would allow you to physically nudge a single reel in hopes of getting it to move by one position, thus scoring a winning combination.

• Tumbling - In games that use the falling symbol metaphor, there is a feature that automatically eliminates winning combinations after they are paid, causing new symbols to tumble from the top. New winning combinations are paid and the symbols tumble again.

Note that, unlike standard re-spins, games offering the automatic tumbling feature do not require any extra wager for it. The amount you bet on the standard spin is all you bet regardless of the number of times the symbols tumble.

That does it for reels and re-spins. Hopefully you now have a thorough understanding of how they work. Be sure to check out the third and final post in the series. It covers bonus games. It is a very good piece, given how many different types of bonus games are currently on offer.