If you notice someone nervously dodging the cracks on pavements or panicking when a black cat crosses their path on a certain date in the calendar, spare a thought for them – they might be suffering from friggatriskaidekaphobia.
The condition is a bit of a mouthful, but to sufferers the issue is very simple – they have a phobia of Friday the 13th.
So why is the day so feared? The most common theory goes that it’s a modern amalgamation of two much older superstitions – that 13 is an unlucky number and Friday is an unlucky day.
Friday is particularly feared in maritime circles and perhaps the most enduring sailing superstition is that it is unlucky to begin a voyage on a Friday.
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Likewise, the number 13 is widely avoided in modern society. High-rise buildings are known to skip the 13th floor, many hospitals have no room 13, aeroplanes have no aisle 13 and some airports omit Gate 13. Italy has even omitted the number 13 from its national lottery.
Whether you take the day at face value or you think it’s all baloney, here are 13 of the oddest rituals that are carried out to keep bad luck at bay.
Touch wood, we’ve got most of them covered:
1. Avoid pavement cracks
As the old nursery rhyme goes: “Don't step on the cracks or you'll break your mother's back.”
2. Knock on wood
This tradition is rooted in western folklore where literally touching or knocking on wood, or merely stating that you are “touching wood”, can avoid “tempting fate” after you’ve perhaps made a favourable observation or a boast.
3. Keep fingers crossed
The common ritual is believed to have originated from the Christian cross. Anything associated with the shape of the cross was thought to bring good luck.
4. Don’t walk under ladders
Before the gallows were invented, murderers were hung from the top of a ladder, and when they died it was said their ghosts remained where they had fallen.
5. Wear something shaped like a four-leaf clover
A four-leaf clover can bring good luck to anyone who comes across one, it is said. According to legend, each leaf represents something: the first is for faith, the second is for hope, the third is for love, and the fourth is for luck.
6. Have a horseshoe in the house
Many believe that hanging up a horseshoe with the ends pointing upwards is good luck as – put simply - it acts as a conductor for any good luck that happens to be floating by.
7. Look out for two magpies
“One for sorrow, two for joy, three for a girl and four for a boy”. The verse comes from an old counting rhyme that still survives today.
8. Don’t get up on the wrong side of the bed
According to Brewer's Dictionary of Phrase and Fable "getting up on the wrong side of the bed" originated from an ancient superstition that getting out of bed with your left leg first was unlucky.
9. Carry an acorn
During the Norman Conquest the English carried dried acorns to protect themselves – it was thought to be an emblem of luck, prosperity, youthfulness and power.
10. Carry a rabbit’s foot
This slightly bizarre superstition originates from China and South America where for centuries it has been thought that carrying a severed rabbit’s foot fends off evil.
11. Don't look at the full moon through a pane of glass
We’ve already checked that there will be no full moon tonight so this superstition need not apply today.
12. Don’t break a mirror
The reflection in the mirror is said to represent the soul and if that mirror was to break, the soul would be damaged. The Romans believed that every person was remade anew every seven years, so by damaging your soul it would take seven years to recover.
13. Avoid black cats
In Western history, black cats have often been looked upon as a symbol of evil omens. Most of western and southern Europe considers the black cat as a symbol of bad luck. If one crosses paths with a person it is believed to be an omen of misfortune and death.
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We also asked our Yahoo! News Facebook and Twitter community to share their personal superstitions with us.
Ultra superstitious Michael Doran told us that he will be spending the day at home... just in case.
Clark Chambers said that if he visits a petrol station today, he will be heading to pump six, even if all the other pumps are empty. He also said: “My brother spits in engine of cars he works on before closing bonnet when finished.”
But for some of our users, the day doesn’t always spell bad luck.
Sammy Shc doesn’t believe in it. She posted on Facebook: “I had a beautiful baby boy on the 13th june so some day it will fall on fri the 13th plus im getting married on a sat the 13th , load of rubbish.”
When Dawn Perry smashed a mirror on Friday 13th, she joked that the day brought bad luck. “Walking under ladders, or opening an umbrella indoors dont bother me. But I accidentelly broke a mirror and within a week I met my (now thankfully ex ) husband. Put up with more than 7 years bad luck with him.”
@Natalie Alice82 tweeted: “@Yahoo!News UK- friday the 13th is one of my fave days. 13 is my fave number, my bday is june 13th & i live on the 13th floor. #Friday13th ☺”
Are you afraid of Friday 13th? Do you practise any superstitions on Friday 13th?