Friday 13th superstition

 

Friday the 13th is widely regarded as an unlucky day in Western superstition and popular culture. This belief combines two separate longstanding associations with misfortune: the number 13 and the day Friday. 

The specific combination of “Friday the 13th” as especially ominous appears to have solidified in the 19th century (with early literary references in France around the 1830s), though its roots draw from much older religious, mythological, and historical ideas.

Here are the main reasons and examples behind why it’s considered unlucky:

The Unlucky Number 13

The number 13 has long been viewed as disruptive or ominous in many cultures, often because 12 symbolises  completeness or perfection (e.g., 12 months in a year, 12 zodiac signs, 12 hours on a clock face, 12 tribes of Israel, 12 labours of Hercules, 12 Olympian gods). Thirteen comes after this “perfect” number, making it feel irregular, excessive, or threatening.

Norse mythology example — In one popular (though somewhat modernised /retold) version of the myth, 12 gods were feasting in Valhalla when the trickster god Loki arrived uninvited as the 13th guest. He tricked the blind god Höðr into killing the beloved god Balder (the god of light and joy) with mistletoe, leading to chaos and suffering. This story is frequently cited as an ancient source for fearing 13 as a bringer of misfortune.

Biblical/Christian example — At the Last Supper, Jesus ate with his 12 apostles, making 13 people total. The 13th (Judas Iscariot) betrayed Jesus that very night, leading to the crucifixion. This reinforced the idea that 13 people at a table (especially a dinner) invites death or betrayal. Many avoided seating 13 at a table for centuries because of this.

Friday as an Unlucky Day

Friday independently carried negative associations in Christian-influenced cultures:

•  Crucifixion of Jesus — Jesus was crucified on a Friday (known as Good Friday), making the day linked to suffering and death.

•  Other biblical misfortunes sometimes tied to Friday include Eve tempting Adam with the forbidden fruit or Cain killing Abel (though these are less consistently dated to Friday in sources).

•  In medieval and later European traditions, Friday was often a day of fasting, penance, or bad omens — people avoided starting major projects, getting married, or sailing on Fridays.

The Combination: Friday + 13

When these two unlucky elements overlap, the superstition becomes especially powerful in popular imagination.

•  Historical event example — On Friday, October 13, 1307, King Philip IV of France ordered the mass arrest of the Knights Templar (a powerful medieval military order). Many were tortured, executed, or disbanded, and the event is often linked (especially in modern retellings) to cementing the date’s bad reputation. (Some historians note this connection may be more legendary than causal, as the full superstition appears later.)

Cultural Reinforcement in Modern Times

The fear was amplified in the 19th–20th centuries through literature, secret societies (like the “Thirteen Club” formed to defy the superstition), and especially horror media:

The Friday the 13th horror film franchise (starting in 1980) with killer Jason Voorhees turned the date into a pop-culture symbol of terror and bad luck.

In reality, statistical studies show no increase in accidents, disasters, or misfortune on Friday the 13th compared to other days — the belief is a classic example of confirmation bias (people notice and remember bad things more on that date). Still, the superstition persists because it taps into deep cultural, religious, and mythological fears of disruption, betrayal, and death.

 Friday the 13th is unlucky because it doubles down on two ancient taboos — the “imperfect” number 13 (betrayal in myths and scripture) and Friday (day of crucifixion and sorrow) — and later events and stories locked the combination into Western folklore. So, what do you mean think? Do you believe it’s unlucky or just superstition? We’d love to hear your thoughts!