UK slot game design rules

What the UK slot game design rules are

Every online casino licensed by the Gambling Commission must follow the Remote Gambling and Software Technical Standards (opens in a new tab), usually shortened to the RTS. In February 2021 the Commission published a package of changes to those standards aimed, in its words, at taking proportionate steps to reduce the intensity of online slots. The changes took effect on 31 October 2021 and have applied to every slot offered to players in Great Britain since.

The rules deal with how a slot plays and what it shows, not with how much it pays. A slot's RTP, volatility and paytable are left to the developer, within separate fairness and testing requirements. What changed in 2021 was the speed of play, whether spins can run on their own, how wins are presented and what information stays on screen. Our UK slot machine rules hub groups these with stake limits, bonus rules and land-based machine law.

The rules apply to casino games of a reel-based type, and the Commission's definition includes games with non-traditional reels. Cluster pays grids, Megaways slot machines and online fruit machines are all treated as slots.

The UK slot game design rules, one by one

The Commission's summary of the RTS changes (opens in a new tab) lists each requirement with a reference number. This table puts them in plain English.

A related rule in the same package, RTS 14B, stopped operators offering reverse withdrawals: once you ask to withdraw, you can't be invited to cancel the request and play the money instead. That applies to all remote operators, not only slots.

Each rule has its own explainer: the autoplay ban, the 2.5 second spin rule, the losses disguised as wins rule and the net position display rule.

Why the Gambling Commission brought in slot design rules

The Commission drew on industry and consumer data, research and its advisory groups. It concluded that the voluntary Betting and Gaming Council code, which already limited spin speed and discouraged turbo features, was not enough by itself. The consultation response introduction (opens in a new tab) records 102 written responses, from members of the public, operators, trade bodies, a charity and an academic.

The autoplay ban was the only proposal most respondents opposed, yet the Commission introduced it anyway, pointing to its consumer research. Responses are not votes, and the Commission weighs the evidence rather than counting heads.

The common thread is intensity. Faster spins, uninterrupted play and celebratory effects can all make a session feel shorter and cheaper than it is. The design features involved are explained in why slot machines are so absorbing.

How a UK-compliant online slot looks

If you open a slot at a UK-licensed casino, the design rules are visible in a few seconds. This checklist shows what to look for.

1. Find the spin button: there should be no autoplay, auto-spin or repeat-spin menu next to it.
2. Look for a session clock showing hours, minutes and seconds since you opened the game or started playing.
3. Look for a net position figure, often labelled as profit or loss for the session, in pounds.
4. Press spin and count: the next spin shouldn't be possible until at least 2.5 seconds after the last one started.
5. Hold down the spin button or space bar: holding it should not start a run of spins.
6. Check the settings: there should be no turbo, quick spin or instant-stop option.
7. Watch a small win below your stake: it may show the amount, but without the win jingle or celebration.

What the slot design rules still allow

The rules are narrower than many players assume. Several familiar features remain permitted, as long as they fit the conditions.

• Fast bonus rounds. The turbo and slam-stop ban doesn't apply to bonus or feature games where no additional stake is wagered, so a free spins round may play out without the player pressing spin each time.
• Real win celebrations. Wins above the total stake can still trigger animations, sounds and counters.
• Result cues for small returns. The game may display the amount awarded, highlight winning lines briefly and play a short sound that differs from the win sound.
• Gamble features. An optional hi-lo gamble is not banned by the design rules, though it is part of the same game cycle for stake limit purposes.
• Cascades and respins. A cascade or a triggered respin inside one paid game cycle isn't a new spin started automatically, so it isn't autoplay.

The rules also don't set a minimum or maximum RTP, a maximum win or a cap on volatility. Those are covered by other parts of the regulatory system, such as testing and the requirement to show game information. See our page on slot RTP information rules for what a game must disclose.

How the slot design rules spread to other casino games in 2025

After its summer 2023 consultation, the Commission extended most of the slot rules to other online casino products from 17 January 2025. Table games such as roulette and blackjack, and house-played poker such as three card poker, now follow similar controls.

The Commission's speed of play decision (opens in a new tab) explains the five-second figure, which runs from the start of one game to the start of the next. Whether the turbo and slam-stop ban was also extended beyond slots was not stated in the Commission's summary, so this page doesn't claim it was.

Do the design rules apply to pub and casino slot machines?

No. The RTS cover remote gambling only. Fruit machines in pubs, machines in arcades and bingo halls, and Category B machines in betting shops and casinos follow the separate Gaming Machine Technical Standards. That is why a pub fruit machine can still have hold and nudge buttons and a different pace of play.

That is changing for new machines. The Commission published finalised machine standards on 30 September 2026, with an interim session standard due from 30 March 2027 and the final standards from 30 June 2027. Trade press reports of the decision say that new Category A, B and C machines will not be allowed to celebrate returns at or below the stake or to offer features that speed up the result, and that new Category B machines will need player limit-setting and an on-screen display of time and net position. Existing machines are reported to be exempt. The detail is tracked on the gaming machine technical standards page.

The 2027 machine changes are described here as reported, because the Commission's full decision document was not available to check line by line. Dates come from the Commission's own technical standards page.

How the slot design rules are enforced

Games are checked by independent test houses before release, and the RTS form part of what they test against. That process is covered in how slot machines are tested. Licence holders remain responsible for what they supply, and the Commission can investigate if a game is found to breach the standards after launch.

In June 2026, slot supplier Stakelogic BV agreed to pay £122,835 after its slots ran below the 2.5-second minimum (opens in a new tab). The case shows that the rules apply to game suppliers as well as to casinos, and that the timing requirement is checked in practice rather than treated as a guideline.

Timeline of the UK slot game design rules

What the slot design rules mean for your costs

The design rules don't change what a slot returns per pound staked, but they do cap how many pounds can be staked in an hour. At the 2.5-second minimum, the most spins possible is 1,440 an hour. At 20p a spin that is £288 staked, and at 96% RTP the long-run average cost is £11.52. Most people spin more slowly, but the ceiling is useful when you plan a budget. Our slot cost per hour page shows how to work it out for your own stake.

Combined with the online slot stake limits of £5 and £2, the design rules put an outer boundary on how intense a session can get. The tools you set yourself, such as deposit limits and reality checks, do the rest.

Where to play slots built to UK design rules

Every casino licensed by the Gambling Commission must offer slots that meet these rules, so you will see the same session clock, net position display and lack of autoplay whichever licensed site you use. The two casinos below are both operated by LC International Limited (Entain), so one person may not be able to open new accounts at both; check the terms.

Coral Casino offers new players aged 18+ 100 free spins worth 10p each after a deposit and £10 or more of slot bets; the spins are on selected games, must be accepted within 48 hours and expire after 7 days, and winnings carry no wagering. New Ladbrokes customers aged 18+ can get up to 500 free spins from Ladbrokes Casino, paid as 50 a day for 10 days, once they deposit and spend £10 on slots; each 10p spin must be claimed before 23:59 and lasts 7 days, with no wagering. Some payment methods don't qualify for either offer, and terms apply.

18+. Gambling should be entertainment that costs money, not a way to make it. Decide a budget before you play: plan a slot budget. Free, confidential help: National Gambling Helpline 0808 8020 133.