Classic 3-reel slots are the simplest slot format: three reels, a handful of paylines and old-school symbols such as fruit, bars, bells and sevens. Online, the best-known examples are NetEnt's Mega Joker and Play'n GO's Fire Joker. Here's how the format works, what the odds look like and how the originals began.
The first commercial slot, Charles Fey's Liberty Bell, had three reels and five symbols.
Mega Joker lists up to 99% RTP, but only at the top stake with its Supermeter; other settings return less.
Fire Joker is a 3×3 game with 5 paylines, 96.15% RTP and an 800× maximum win.
Online 3-reel games use a random number generator, so the number of symbols you can see doesn't tell you the odds.
Reels
3
Typical paylines
1 to 5
Highest RTP listed
Up to 99% (Mega Joker, top stake with Supermeter)
Fire Joker max win
800× stake
UK stake cap
£5 a spin (25+), £2 (18–24)
What classic 3-reel slots are
A classic slot copies the layout of the mechanical machines that came before video screens. It has three reels, usually showing three symbols each, and pays on a small number of lines. The symbol set is traditional: cherries, lemons, plums, bars, bells, sevens and sometimes a joker or a star.
The appeal is clarity. There are no cascades, character modes or collection meters to learn, and you can read the whole paytable in seconds. That doesn't make the games low risk, as Mega Joker shows. For other looks, browse the slot themes hub, or see our separate page on fruit slots, which covers the wider fruit-symbol family on five reels.
Classic 3-reel slots compared, plus classic-style five-reelers
Only two games in our checked data are true 3-reel slots. We've added two five-reel games that keep the classic symbols, so you can see how the extra reels change the numbers.
Notice that Sizzling Hot Deluxe keeps the same five paylines as the two 3-reelers but adds two reels and a much higher cap. Twin Spin drops lines altogether for 243 ways.
How 3-reel slot odds work
On a mechanical machine, the odds came straight from counting. Take an illustrative reel with 20 symbol positions. Three such reels give 20 × 20 × 20 = 8,000 possible stops. If each reel holds one jackpot symbol, three in a row comes up 1 time in 8,000 on average.
That simple counting limited how big a top prize could be. The fix came with Inge Telnaes's 1984 US patent for using a random number generator to pick reel stops. With 256 virtual stops per reel, a 3-reel game has 256 × 256 × 256 = 16,777,216 combinations, even though you still only see a few symbols on each strip.
Combinations on a three-reel game
Stops per reel
Calculation
Total combinations
Chance of one set result
10
10 × 10 × 10
1,000
1 in 1,000
20
20 × 20 × 20
8,000
1 in 8,000
22
22 × 22 × 22
10,648
1 in 10,648
256 (virtual)
256 × 256 × 256
16,777,216
1 in 16,777,216
Modern online classics work on the same virtual principle. The game's random number generator picks the outcome, and symbols can be weighted so a seven appears far less often than a cherry. The three reels on screen are a display, not a count of your chances. That's why the published RTP matters more than how 'simple' a game looks.
Mega Joker: why the 99% headline needs care
Mega Joker is the 3-reel game most often quoted for RTP. NetEnt's figure is up to 99%, and the key words are 'up to'. That top figure applies at the top stake with the Supermeter, which adds a second set of reels. At other settings the return is lower, so check the help screen for the figure that applies to how you're playing.
It's also rated high volatility, and the top prize is a random progressive jackpot rather than a fixed multiple. In other words, a very high long-run return sits alongside big swings. On £100 of total stakes, 99% means an average cost of £1, but you could easily lose the full £100 in a session or win more than you staked.
UK stake caps apply here too: the maximum is £5 a spin for players aged 25 and over and £2 for those aged 18 to 24, whatever the game's own top stake setting.
Fire Joker and the modern classic
Fire Joker shows how studios update the format without losing the look. It keeps a 3×3 grid and 5 paylines, with medium volatility, a 96.15% RTP and a maximum win of 800× stake. At a 20p stake, that ceiling is £160; at £1 it's £800.
On a small budget, Fire Joker's medium rating means wins come along more evenly than on a high-volatility game. £20 at 10p gives 200 spins; at 50p, 40. Over £100 of stakes, the average cost at 96.15% is £3.85. Compare more games on our low volatility slots and high RTP slots pages.
From the Liberty Bell to online classic slots
The 3-reel format is as old as the slot machine itself. Charles Fey (opens in a new tab) of San Francisco built the Liberty Bell with three reels and five symbols: horseshoes, diamonds, spades, hearts and a Liberty Bell. Three bells paid ten nickels, or 50 cents. Sources disagree on the date; one gives 1898, another says some time between 1887 and 1895, and a surviving machine from 1899 is held in a Nevada collection.
Timeline of the classic slot
Date
Event
1887–1898 (sources differ)
Charles Fey builds the three-reel Liberty Bell
1907
Herbert Mills produces a version of the Liberty Bell
Date not confirmed
Mills's Operator Bell adds a fruit-gum vending attachment, bringing fruit symbols and, from a gum stick, the bar
1963/64 (sources differ)
Bally's Money Honey, the first fully electromechanical slot, pays up to 500 coins automatically
1976
Fortune Coin develops the first video slot machine
1981
Electrocoin's Bar-X is created; it's in UK arcades by 1983
1984
Inge Telnaes receives the patent behind virtual reels
The game design rules ban autoplay, turbo and slam-stop, require at least 2.5 seconds per spin, and stop games celebrating a return of your stake or less. Since a Gambling Commission warning in January 2020, feature buy-ins are not offered to British players. You'll also need to be age-verified before you can play, demo games included. See slot stake limits for the detail.
Where to play classic 3-reel slots in the UK
None of our partner offers is set on a classic 3-reel game. They are slot welcome deals with fixed or selected games, so look in each casino's lobby for Mega Joker or Fire Joker. All three are for over-18s, and terms apply.
PlayOJO: first deposit of at least £10 from a new UK customer (Northern Ireland excluded) brings 80 free spins on Big Bass Bonanza at 10p each. No wagering applies, so winnings are cash. It can't be combined with other offers and works only through the designated offer link.
Coral: bet £10 on slots, get 100 free spins. New players deposit (some methods excluded) and bet £10 or more on slots between 1 October 2026 and 1 February 2027. The 10p spins are on selected games, must be accepted within 48 hours and last 7 days; there's no wagering on their winnings. Paying in by Neteller, PayPal, Paysafe, Skrill, a prepaid card or certain debit cards rules you out.
Ladbrokes: play £10 on slots, get up to 500 free spins. New customers receive 50 spins a day for 10 days, 10p each on selected games; claim them before 23:59 each day and use them within 7 days. No wagering. Prepaid card, PayPal, Paysafe, Neteller, Skrill and Moneybookers deposits are left out.
Coral and Ladbrokes are run by the same company, LC International Limited, so you may only be able to join one as a new customer. Our PlayOJO slots page covers what that casino publishes about its slot range.
Coral and Ladbrokes are both run by LC International Limited (Entain). If you already hold an account with one Entain brand, you may not be able to open another; check the terms first.
Significant terms: 18+. New UK customers (excluding Northern Ireland). First deposit only. Minimum deposit £10. 80 free spins on Big Bass Bonanza, £0.10 each. No wagering requirements; winnings paid in cash. Cannot be used with any other offer. Only available to players who arrive through the designated offer link. Full T&Cs apply. GamCare.org.uk
Read our PlayOJO reviewLicence: Skill On Net Limited, Gambling Commission account 39326. Offer checked 5 October 2026.
Significant terms: 18+. New players only. Offer runs 01/10/2026 to 01/02/2027. Deposit (certain types excluded) and bet £10+ on slot games to get 100 free spins (selected games, £0.10 each, 48 hrs to accept, valid 7 days). No wagering on free spin winnings. Deposits by Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards do not qualify. Restrictions and T&Cs apply. GamCare.org.uk
Read our Coral reviewLicence: LC International Limited, Gambling Commission account 54743. Offer checked 5 October 2026.
Time limitClaim daily for 10 days; each batch valid 7 days
Worked valueUp to 500 spins at £0.10 (up to £50 in spins)
Significant terms: 18+. New customers only, from 14/11/25 until further notice. Certain deposit methods excluded. Deposit and spend £10+ on slots for 50 free spins a day during the first 10 days after first deposit and registration (max 500, £0.10 each, selected games, claim before 23:59 each day, valid 7 days). No wagering. Prepaid cards, PayPal, Paysafe, Neteller, Skrill and Moneybookers deposits do not qualify. Restrictions and T&Cs apply. GamCare.org.uk
Read our Ladbrokes reviewLicence: LC International Limited, Gambling Commission account 54743. Offer checked 5 October 2026.
18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.
Frequently asked questions
What is a classic 3-reel slot?
It's a slot with three reels, usually three symbols high, that pays on a small number of lines using traditional symbols such as fruit, bars, bells and sevens. The design copies the mechanical machines of the early 20th century. Online examples include Mega Joker and Fire Joker. Our guide to how slots work explains the reels, lines and random number generator behind them.
Do 3-reel slots have better odds than 5-reel slots?
Not automatically. The number of reels on screen doesn't set the odds; the game's maths and RTP do. Mega Joker lists up to 99% at its top setting, while Fire Joker lists 96.15%, which is similar to many five-reel games. Compare published RTPs and volatility instead of counting reels. Our slot RTP page shows how to turn a percentage into an average cost.
What is the RTP of Mega Joker?
NetEnt lists Mega Joker at up to 99%, but that figure applies at the top stake with the Supermeter mode. At other settings it returns less, so read the help screen for the figure that matches how you're playing. It's rated high volatility, with a random progressive jackpot. The Mega Joker review explains the Supermeter and the game's other settings.
What is the maximum win on Fire Joker?
Fire Joker's maximum win is 800× your stake. At a 10p stake that's £80, at 20p it's £160, and at £1 it's £800. It's a medium-volatility 3×3 slot with 5 paylines and a 96.15% RTP, so the ceiling is modest but wins tend to be steadier than on high-volatility games. See the Fire Joker review for the full specification.
Who invented the 3-reel slot machine?
Charles Fey of San Francisco is credited with the Liberty Bell, the three-reel machine with horseshoes, diamonds, spades, hearts and a bell. Sources disagree on the date: one says 1898, another places it between 1887 and 1895, and a machine from 1899 survives. Three bells paid 50 cents. Our answer to who invented the slot machine covers the competing accounts.
Why do classic slots have fruit and bar symbols?
The fruit came from chewing gum. The Mills Operator Bell had an optional vending attachment for fruit-flavoured gum, so cherries, lemons, oranges and plums appeared on the reels. The bar symbol is said to come from a stick of Bell-Fruit Gum pictured on the machine. Read more in our history of slot machines, which follows the story to online games.
Are classic 3-reel slots good for small budgets?
They can be, if you pick a medium-volatility game such as Fire Joker and a low stake. £20 at 10p gives 200 spins. A high-volatility classic like Mega Joker can drain a small budget quickly despite its high RTP at the top setting. Our guide to casino games for small budgets compares slots with other games on cost per hour.
Are online classic slots the same as pub fruit machines?
No. Pub fruit machines are land-based gaming machines with their own stake and prize rules, and they often include holds and nudges. Online classics are remote games under the Gambling Commission's online rules, with RNG outcomes and published RTPs. Our page on why slot RTPs are higher online than in pubs explains one of the biggest differences.
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