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Slots Odds

If you thought winning at online slots was about slamming the 'Spin' button, crossing your fingers, and hoping for the best, think again.

It's important to have even a basic understanding of the odds involved in slots if you're going to choose the right game and have a profitable slots life.

Today's video slots are hugely complicated and well-crafted beasts, and while that means they're safer than ever, it also means they're harder to predict.

Random Number Generators

Once upon a time, slot machines were mechanical behemoths powered by mechanisms that fixed the various combinations that the slot landed on.

Today's video slots, however, are powered by microprocessors (and programs in online slots) called Random Number Generators.

RNGs are formulae programmed into the games which generate random numbers (or arrangements of symbols) as the reels fall.

Any good online casino will have its RNGs audited by an independent body like eCOGRA or TST regularly for fairness. Software developers themselves are also audited before they can be given out gaming licences to operate.

Slot Par Sheets

Every new online slots has a 'par sheet', a blueprint for the payouts and permutations that goes into the game.

On a typical par sheet you'll find a list of the symbols featured on each reel and the quantity. The number of symbols on each reel varies wildly from one slot to another, and that's what can affect the payouts.

Where one game has 30 symbols on a reel, for example, another may have over 200; that can result in many more thousands of possible winning (or losing) combinations.

Par sheets will also list jackpot totals and how many spins are typically needed to hit a jackpot. Remember, though, this doesn't mean a slot is fixed; the reels still spin at random and independently of each other.

Payouts and Combinations

While it's not necessary to calculate every odds in a slot, it's a good idea to have a rough idea of how often a three-symbol combination hits.

The chance of you hitting a winner is related to the amount of reels in the slot and the number of icons on each of the reels.

Let's take a classic 3-reel slot. With three reels, and 20 symbols on each reel, the odds of hitting one exact symbol is 20/1, or 1 in 20. If it's 20/1 to hit one symbol, then it's 20x20x20 = 1 in 8,000 to hit a combination of three symbols; or, there are 8,000 possible combos.

Now let's say you're looking to hit a jackpot with special bonus symbols. There's just one of those on each reel, so the chance of hitting the jackpot is 1/8,000. If you have four jackpot symbols on each reel, your chances of hitting a winning combo drastically lower to 4/20 x 4/20 x 4/20 = 12 / 8,000 = 1 in 666.

But most online slots have five reels, which puts the possible combinations into the millions.

Understanding RTP (Return to Player Percentages)

Every slot is designed to pay back a certain percentage of bets to players over the long term. These Return to Player Percentages (RTP%) vary from game to game, and are theoretical. In addition, the RTPs are usually calculated over a very long-term period of betting.

Remember that slots spins are random, but odds are programmed into slots depending on the number and layout of symbols on the reels.

Many online casinos and developers list their RTPs. You'll even find them tucked away in the slot Paytable. Online slots tend to have better RTPs than their land-based cousins (ranging from 85% in a live casino to up to 97% in an online casino), and it's a good idea to get used to which slots offer the best long-term payouts.

Volatility in Slots

You'll sometimes hear slots referred to by their volatility.

Essentially, high-volatility or volatile slots carry a higher risk to your bankroll. You might go a long period without winning a penny, then hit a big jackpot.

On the reverse, low-volatility slots offer plenty of frequent, smaller wins. You might not hit a big jackpot as with a volatile slot, but they're better on your wallet - and your heart!

For action junkies looking for the big win, high-volatility slots offer lots of action but you'll need to weather the variance (swings in bad and good luck).

For an easy way to work out if a slot is volatile, head to the paytable. Every slot has one that lists the various payouts and jackpots. If there seems to be a lot of mega jackpots in the game, it's probably high-volatility.

Volatility is a personal preference at the end of the day. If you can handle the barren periods but want to hit that once-in-a-hundred-spins jackpot, choose a high-volatility slot. If you prefer a small win every couple of spins, a low-volatility game is for you.

Find the Best UK Slots On The Net

Whether you're into 3-reel slots that keep you spinning and spinning until you hit a win, or you love the frequent small wins of a low-volatility slot, we have games for you.

At, we offer UK players hundreds of free-play slots so you can test out the games, check the RTPs and see if that bonus feature really is as random as it seems.

Then, once you're ready, sign up to a real-money casino and put your slots bankroll to the test.

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