UK Slots – What is RTP and How Does it Work?

by Michelle M | Casino & iGaming Writer

22 April 2025 0 275

📖 Short Read (4 mins)

Last Updated on 3 May 2025 by Michelle M

This is a shortened and summarised version of this page — we have included key points and important information.

🎯 RTP = Return to Player (but it’s not a guarantee): A slot with 96% RTP doesn’t mean you’ll get £96 back from every £100 wagered – it’s a long-term average across millions of spins.

🌀 Short-term results vary wildly: RTP doesn’t control how lucky or unlucky you’ll be in a single session – variance (or volatility) is what really affects short-term wins and losses.

⚠️ Watch out for variable RTPs: Many UK slots now have multiple RTP settings – the same game might run at 96%, 94%, 90% or even lower, depending on the casino.

🔍 Always check which version you’re playing: Some sites still advertise the highest RTP, even if the version running is lower – check the info screen, footer, or ask support directly.

📉 Lower RTP = higher house edge: The difference between 96% and 90% might seem small, but it adds up over time – especially if you’re a frequent or high-stakes player.

📜 UKGC demands transparency, not limits: Casinos must clearly show the RTP version in use, but there’s no law stopping them from using the lowest setting.

✅ Casinos etc. recommends choosing higher RTPs where possible: But also weigh up volatility, hit rate, bonus features, and fun factor – RTP is just one part of what makes a slot worth playing.

How RTP Actually Works in UK Slots (and Why It’s Not What You Think)

If you’ve spent any time playing online slots in the UK, you’ve probably asked yourself – what is RTP? It’s short for Return to Player and is usually expressed as a percentage, like 96%, it’s often used by players as a benchmark for whether a slot is “worth playing.”

But here’s the thing: RTP is one of the most misunderstood aspects of slot gaming, and the reality is far more nuanced than many guides make it out to be. In this post, we’ll break down what RTP actually means, how it’s calculated, why it doesn’t guarantee your results, and how variable RTP settings are affecting UK players in 2025.

What is RTP – Table of Contents

What Is RTP?

RTP stands for Return to Player, and it refers to the average percentage of wagered money that a slot is expected to pay back to players over a long period of time. Many of the best online slots offer higher RTP rates.

So if a slot has an RTP of 96%, that means – in theory – for every £100 wagered, the game pays back £96 in winnings. The remaining £4 represents the house edge (the casino’s long-term profit).

Why RTP Doesn’t Mean What Most People Think

Here’s where things get tricky. A lot of players assume that a high RTP means better chances of winning in the short term. But that’s not how it works.

RTP is based on millions or even billions of simulated spins, and the figure represents a long-term statistical average. It’s not a promise, and it doesn’t mean that if you spin £100 today, you’ll definitely walk away with £96.

You could win £500, or you could lose your stake completely. That’s variance – or volatility – in action, and it’s a separate mechanic altogether.

What Determines the RTP?

RTP is built into a slot’s code, based on how symbols are weighted, how often features trigger, how jackpots are structured, and so on. Developers simulate huge datasets to calculate the theoretical return.

In the UK, regulated slots must clearly display the RTP, and operators are required to only offer approved versions under licence. However, since around 2021–2022, variable RTP slots have started becoming more common.

What Are Variable RTP Slots?

A variable RTP slot is one where the game has multiple RTP settings – say 85%, 90%, 94%, and 96% – and it’s up to the casino operator to choose which version to run.

So while the official game info may show 96%, the casino might be offering a lower version, like 92%, and unless they clearly disclose this, you might not even notice.

This has become a major talking point among UK players and affiliates, especially as some operators quietly use lower RTP settings to increase profit margins.

Why Do Casinos Offer Lower RTP Versions?

In theory, a lower RTP version lets casinos make more money. In practice, it often comes down to the platform or provider. Some white-label operators might default to the lowest available version to stay competitive or cover costs.

Unfortunately, this practice puts more pressure on players who are expecting a “fair” experience. The difference between 96% and 90% might not sound huge, but over time, it adds up – especially for higher-stakes or frequent players.

Can You Check Which RTP Version You’re Playing?

Yes – but it takes a bit of effort. Here’s how:

Check the paytable or info screen: Most slots include the RTP figure in the game rules.
Look at the footer or help section: Some casinos mention the RTP version here.
Use comparison sites: Websites like Casinos etc list the actual RTP version offered at each casino.
Ask support: If you’re not sure, customer service should be able to tell you which version is in use.

UK Regulation on RTP

The UK Gambling Commission requires transparency around RTP, but there’s currently no restriction on variable RTPs – as long as the version in use is disclosed.

That said, the Gambling Commission has taken a stricter stance in recent years on misleading information, so failure to show the correct RTP could put a casino at risk of non-compliance.

As a player, this means it’s more important than ever to check the small print before spinning.

So Should You Always Choose the Highest RTP?

In general, yes – if everything else is equal, the higher RTP version will give you better theoretical returns in the long run.

But it’s not the only thing that matters. Volatility, hit frequency, bonus features, and max win potential all affect how a slot feels to play and how it pays out.

In fact, some low-RTP games still attract players because they offer huge jackpot potential or entertaining features. If you’re playing for fun and not expecting consistent wins, you might be fine with a lower RTP – but it’s good to be aware of what you’re walking into.

What is RTP – Final Thoughts

RTP is a useful guide, but it’s not a guarantee. It tells you what the game might return over thousands of spins, not what you will get on your next spin.

With variable RTP slots becoming more common in the UK, it’s essential to check the version you’re playing – and don’t assume the advertised number is what you’re actually getting.

Play smart, choose transparent casinos, and always spin with the understanding that RTP is only one part of a much bigger puzzle.