The Basics of How Online Slots Work


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Have you ever spun a slot on your phone or laptop and couldn't help but wonder how they work? Well, you are not alone as lots of players also want the nitty-gritty on what’s happening behind those flashing lights. In this guide, we are going to deep dive into how online slots work, breaking it all down and covering:
• the basics of how slots work,
• how you might win a bit of cash
• and what to watch out for.
From the techy bits to the fun stuff, we’ve got you covered. Let’s dive in and figure it out together.
*New UK customers only. Deposit & Stake Min £10. Debit card only (exclusions apply). 150 free spins (£0.10) on selected games. No wagering requerments on Free Spins Winings. Spins expire after 7 days. 18+ BeGambleAware.org. Full Terms apply
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Understanding the Basics of How Do Online Slots Work
At their core, slots are digital games built to dish out wins based on luck. Designers and developers program these slots to feature themes like pirates, jungles, or whatever, along with animations that pop and tunes that keep you tapping your foot. You’ve got reels spinning, symbols landing, and a Random Number Generator (RNG) that decides whether or not you win. That RNG’s the real deal as it constantly spits out random combos so every spin is a fresh roll of the dice as it were. Beyond that, it is about paylines (lines that pay when symbols match), bets you set, and features like free spins or bonuses that spice things up.
Is There Any Difference for UK Players?
Yes, for UK players, it is a bit different and more tightly regulated. The British gambling scene is regulated by the UK Gambling Commission, so online slots here have to play fair. Payouts are checked, RNGs are legit, and casinos must be licensed - unlike some offshore sites with less strict rules. UK slots also cap stakes on some games and push responsible and safe gambling hard, which you won’t always see in some markets.
BetMGM
New customers only. Opt-in required. Deposit £10 or more & wager 30x on casino games (contributions may vary) for 100% deposit match up to £200 extra & 100 Free Spins. Free spins on Big Bass Splash worth 10p each valid for 3 days. 7 days to deposit, wager, claim. One offer per player. 18+. T&Cs apply.
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Leo Vegas
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Bet365
Min. £10 in lifetime deposits required. Offer must be claimed within 30 days of registering a bet365 account. Select prizes of 5, 10, 20 or 50 Free Spins: 10 selections available within 20 days, 24 hours between each selection. Max. prize, game restrictions, time limits and T&Cs apply. Registration Required. #Ad
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What Are the Slot Providers?
Slot providers are the brains behind the games. They program the slots you play, and the UK has some cracking ones on offer. Popular providers in UK include:
Then there is Microgaming, churning out biggies like Mega Moolah, and Big Time Gaming, the providers of Megaways. They are all over UK casinos, bringing different vibes, sharp graphics, mad features, or just solid spins.
How Many Types of Slots Are There?
Slots aren't all the same and there are a few types to pick from:
- Video Slots: These ones feature 5 reels, vibrant themes, and bonus rounds and they are just about the most likely of what you will see online.
- 3-Reel Slots: Old-school, simple stuff with three reels, fewer paylines, a bit like pub fruit machines.
- 5-Reel Slots: They are the standard now featuring more paylines and are usually packed with extras.
- Others: Weird ones like grid slots or progressive jackpots that grow till someone wins big.
Whatever your preference is, there is always something for everyone.

Paddy Power
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Features That You Should Know
Here are some slot features and terminologies that you should know:
- Reels and Rows: Reels spin vertically and rows go across. There are usually 3-5 reels and 3-4 rows. More reels and rows mean more ways to win.
- Return-to-Player (RTP): This is the percentage of cash the slot pays back over time. A 96% RTP means £96 back per £100 bet, long-term. If you want the full rundown, you can check our RTP guide [insert link].
- Volatility: This refers to how risky a slot is. Low volatility slots feature more steady but smaller wins, and high volatility slots have bigger payouts at a greater risk. You can learn more in our RTP guide [insert link].
- Symbols: These are icons that pay. Low ones include (cards like 10, J), high ones are (themed stuff like pirates), wilds swap for others and scatters trigger bonuses.
- Paylines: Lines where matching symbols pay. It could be 10, 20, or even hundreds.
Bonus: Bonuses include free spins, mini-games and extras that keep it lively.
Understanding these features will get you a step ahead in the game.
Mechanics You Need to Know
Some slots feature unique mechanics, here is a list of them:
- Megaways: There are no fixed paylines with up to 117,649 ways to win.
- Grid Slots: This slot offers you a choice to ditch reels for a grid and match clusters.
- Link & Win: Land special symbols, lock them in, and grab a prize if you fill the screen.
- Others: Includes cascading wins (symbols drop away) or jackpots that climb till they pop.
Truths and Lies about online Slots
Let’s bust some myths about slot games.
- Are online slots rigged? Not if they are legitimate. UK slots use RNGs that are audited to be fair.
- Can you always win? No, it’s always based on luck and anyone saying otherwise is flogging you a dream.
- House always wins? Well, sort of. Over time, the RTP (Return to Player) ensures the house has an edge. But that doesn't mean you can't get lucky. For more details, check out our in-depth article on the House Edge in gambling.
3 Essential Tips You Should Know When Playing Online Slots
If you are new to slots, here’s some tips to keep in mind:
- Always set a Budget: Decide your limit, for example £20, and don’t budge, win or lose.
- Test in Demo Mode: Try it for free first to see if it’s your vibe before betting real cash.
- Pick RTP and Volatility: Select slots with higher RTP (96%+) and one with a volatility that suits you. Remember, low for steady, high for big swings.
Just keep it fun without breaking the bank.
The Importance of Responsible Gambling
Slots can be fun until you lose money then they are not, so always know when to tap out. Set limits, take regular breaks, and if it’s getting heavy, there is help. GambleAware, Gamblers Anonymous, or the NHS are solid picks if you need a hand.
How to Choose the Best Online Slot For Me?
Finding the right slot depends on you but make sure to consider the mix of theme, RTP, volatility, and other features. If you like big wins, then high volatility slots are likely to be your preferred option, while low volatility slots are likely to allow for longer gametime. Fancy graphics or simple spins? Pick what clicks. For newbies, you can try these:
18+ New Customers Only. Opt in, deposit and wager £10 on selected slots to get a £25 Slots bonus on selected slots, 30x wagering, max redeem £500, 20-day expiry. Claim offer max x2 in 10 days of sign up to get a max of £50 in Bonuses. Scroll down for T&Cs. GambleAware.org | Please gamble responsibly
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You can start there and see what works best for you.
Tim Mirroman
Author
As a seasoned content writer and copywriter specialising in iGaming, Tim Mirroman brings over 8 years of expertise in crafting high-quality, engaging content that resonates with diverse audiences. With a strong passion for the iGaming industry, he has developed a unique understanding of the sector's nuances and trends. Tim worked with numerous iGaming brands and platforms, creating content that drives player acquisition, retention, and conversion.