Double bar slot machine symbol

What the double bar slot machine symbol means

Think of the double bar as a rank marker. Classic reel games use a short ladder of bar icons, and the number of blocks tells you where each one stands: one block is the cheapest bar, two blocks sit in the middle and three blocks top the family. Below the bars you usually find fruit such as the cherry, and above them the lucky seven or a game’s logo.

Because the design is so plain, the double bar is easy to read at a glance. That was the point on mechanical reels, where a player needed to see a line of matching shapes from a few feet away. The idea carried straight into video and online classic slots, which is why you still see the same stacked rectangles on games built decades later. Our wider slot machine symbols guide shows where the double bar fits among the other traditional icons.

The double bar is not a wild or a scatter unless a particular game’s rules say so. On almost every classic game it is a plain paying symbol that must line up on an active payline.

Where the double bar symbol came from

The story starts with the single bar. According to the published history of slot machines on Wikipedia’s slot machine article (opens in a new tab), the Mills Operator’s Bell had an optional gum-vending attachment, and a picture of a stick of Bell-Fruit Gum appeared on the machine. That rectangle of gum is given as the origin of the BAR. Because the gum was fruit-flavoured, the same machines put lemons, cherries, oranges and plums on the reels, which is where fruit symbols come from.

Our checked history sources do not record who first printed two bars stacked together, or in what year. Rather than repeat an unsourced date, it is fairer to say the double bar grew out of the single BAR as makers needed more paying ranks on the same reel. Stacking extra blocks was a cheap way to create new symbols that players could rank instantly without learning a new picture.

The Mills Novelty Company, and the rival makers that copied its symbol set, helped spread the bar-and-fruit look across the United States. The single BAR symbol page covers that origin in more detail.

Single, double and triple bar: how the ranking works

On a typical classic paytable the three bars form a neat step pattern. The table below is an illustration of the shape you often see, not the paytable of any real game, so use it to understand the logic and then check the real figures in the game you are looking at.

The pattern is not a law. Some games pay doubles and triples the same, some skip the double bar entirely, and some fruit machines use bars as feature symbols rather than straightforward pays. The triple bar page looks at the top of the ladder from its own angle.

Mixed bars and the ‘any bar’ win on a double bar slot machine

Plenty of classic reel games include an ‘any bar’ line: three bar symbols of any kind, such as single, double, triple. It pays less than three matching bars because there are far more ways to land it. For a double bar this matters, because it can contribute to a mixed line as well as to its own three-of-a-kind.

Worked example: counting bar combinations

Imagine a three-reel game where each reel has 64 virtual stops. On each reel, 8 stops are single bars, 6 are double bars and 4 are triple bars, so 18 of 64 stops show some kind of bar. The total number of outcomes is 64 × 64 × 64 = 262,144.

• Three double bars: 6 × 6 × 6 = 216 outcomes, about 1 in 1,214 spins.
• Any three bars: 18 × 18 × 18 = 5,832 outcomes.
• Remove the pure lines (512 single, 216 double, 64 triple = 792) and 5,040 mixed outcomes remain, about 1 in 52 spins.
• If three doubles pay 25× and mixed bars pay 5×, the doubles return about 2.1% of stakes and the mixed line about 9.6%.

So in this made-up game the humble mixed line gives back more than four times as much as three double bars. That is typical of how classic maths spreads the return: frequent small hits keep a game ticking, rare lines carry the bigger multiples. You can read more on how designers balance this in our guide to slot machine maths.

Why the double bar slot machine symbol pays what it does: reel strips and weighting

Every symbol’s prize is tied to how often it appears. On an old mechanical machine that meant counting physical stops on the reel strip. Since microprocessors arrived, makers can map each physical picture to several positions on a much longer virtual reel, so a double bar can appear on the glass as often as any other symbol while being chosen far less often by the random number generator.

This is called weighting, and it is why the double bars you see just above or below the line say nothing about your chances. The random number generator picks the stop positions first; the reels then animate to show that result. Two bars hovering one row away from a payline is a display effect, not a sign that a win is close.

Double bars on UK fruit machines

Bar icons have been part of British fruit machines for decades, alongside cherries, bells and sevens. On a pub machine the double bar can appear in the base game, on a feature reel or as part of a ‘hold’ decision, where the machine offers to keep some reels in place for the next spin. Our guide to nudges explains how those offers work.

The most common pub and arcade machines are Category C, which have a maximum stake of £1 and a maximum prize of £100, and are for players aged 18 and over. The Gambling Commission lists every limit on its gaming machine categories page (opens in a new tab). That prize cap shapes the paytable: a double bar line on a Category C machine pays a modest sum, and the bigger amounts come from features and the jackpot.

Using a hold or nudge sensibly can stop you missing a win the machine has offered, but it does not change the machine’s built-in payout percentage. Many UK machines are also compensated, meaning recent play can influence what comes next, which the machine must state. See compensated fruit machines for how that differs from a random game.

Double bars in online classic slots

Online, the double bar lives on in classic slot machines and fruit slots that copy the three-reel look. The online version follows UK online rules rather than machine categories: since 31 October 2021 there is no autoplay, no turbo or slam-stop, and each spin takes at least 2.5 seconds. Stakes are capped at £5 a spin for players aged 25 and over and £2 for those aged 18 to 24.

The Gambling Commission’s remote technical standard on game rules and the likelihood of winning (opens in a new tab) requires licensed games to show players the rules and how prizes are paid. In practice that means the double bar’s value is printed in the paytable, usually as a multiple of the line stake or as a cash amount that changes with your bet.

How to check what a double bar pays

1. Open the game and set your normal stake before reading any prize values.
2. Tap the ‘i’, menu or paytable button and find the bar section.
3. Note the prize for three double bars and whether an ‘any bar’ line exists.
4. Check whether bars pay on every line or only the centre line.
5. Read the help screen for the RTP figure, which covers the whole game, not just bars.
6. On a pub machine, read the pay card on the glass and the stated return percentage.

Our step-by-step guide to reading a paytable covers the same process for modern video slots.

Double bar slot machine myths

For a fuller look at why near misses mean nothing, see slot machine near misses.

Where to play classic slots with bar symbols

None of our partner offers is tied to a bar-symbol game, so treat the boxes below as general slot offers. Coral’s offer (1 October 2026 to 1 February 2027) gives new players aged 18+ 100 free spins worth 10p each after depositing and betting £10 or more on slots; the spins are on selected games, must be accepted within 48 hours and last 7 days, with no wagering on winnings and some payment methods excluded. Ladbrokes gives up to 500 free spins, 50 a day for 10 days, after a £10 slots spend, again at 10p a spin with no wagering. Read our Coral and Ladbrokes pages for the full terms.

PlayOJO’s 80 no-wagering spins are played on Big Bass Bonanza rather than a classic game. Game libraries change, so search each casino’s lobby for classic or fruit slots. All offers are for over-18s only and terms apply. Treat any stake as the cost of entertainment, and set a deposit limit before you start.

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.