Why Is Friday the 13th Unlucky and Where the Fear Began

Next Friday is the 13th of November, and somewhere a person is already moving a flight, putting off signing a lease or quietly deciding not to start anything new that day. Most of them could not tell you where the fear comes from, only that everyone seems to share it.

So why is Friday the 13th unlucky? The short answer is that two older superstitions, one about the number 13 and one about Fridays, were glued together surprisingly recently. The longer answer involves a dinner table, a Norse god, a stockbroker's novel and a lot of film studios. Here is how it all fits together.

Why is Friday the 13th unlucky in the first place

Neither half of the date was trusted on its own for centuries before anyone combined them.

The trouble with the number 13

Twelve has long been treated as a complete number. There are 12 months, 12 signs of the zodiac, 12 hours on a clock face and 12 apostles. Thirteen sits just past that neat whole, which made it feel excessive or out of order to many cultures.

Two dinner stories gave the number its reputation. In Christian tradition, 13 people sat at the Last Supper, and the 13th guest to arrive is often said to be Judas. In Norse mythology, 12 gods were feasting in Valhalla when the trickster Loki turned up uninvited as the 13th guest and arranged the death of Baldr, the beloved god of light. The lesson people took from both was simple: 13 at a table means someone will not be there for long.

That fear stuck. In 1881 a group in New York even formed the Thirteen Club, which met on the 13th of the month, seated 13 members at each table and walked under ladders on the way in, all to mock the superstition. Most people were not so bold. Hosts in London and Paris kept spare guests on call so a dinner party would never seat 13.

Why Friday got a bad name

Friday carried its own weight. In Christian belief it was the day of the crucifixion, and medieval writers also claimed it was the day Eve offered Adam the apple. In Britain, Friday was the traditional day for public hangings, which earned it the nickname "hangman's day." Sailors refused to begin voyages on a Friday, and Geoffrey Chaucer mentioned bad things happening on a Friday as early as the 1390s.

When the two fears finally joined

Here is the surprising part. There is very little written evidence of anyone fearing Friday the 13th as a specific date before the late 19th century. The two superstitions existed side by side for hundreds of years without being combined.

The first clear references appear in the late 1800s in Britain and the United States. Then in 1907 a Boston stockbroker called Thomas W. Lawson published a novel titled Friday, the Thirteenth, about a broker who uses the superstition to cause a panic on the stock market. The book sold well, and the phrase spread through newspapers.

From there, popular culture did the rest. The 1980 horror film Friday the 13th and its long run of sequels fixed the date in the minds of people who had never heard of Loki or Lawson.

The Knights Templar story and why it does not hold up

You will often read that the curse began on Friday 13 October 1307, when King Philip IV of France ordered the mass arrest of the Knights Templar. The arrests were real, and the date really was a Friday the 13th.

But I would push back on the idea that this is the origin. There is no record of people in the 14th, 15th or 16th centuries linking that date to bad luck. The Templar connection was mostly popularised in the 20th century and then given a huge boost by thriller novels around 2003. It is a great story attached after the fact, not the root of the belief. If a superstition seems to have one tidy origin event, that is usually a sign that someone worked backwards.

The same pattern shows up in plenty of other habits. Our look at why people knock on wood found a similar gap between the popular explanation and the written record.

How the fear shows up today

The fear of the number 13 is called triskaidekaphobia. The specific fear of Friday the 13th has an even longer name: paraskevidekatriaphobia, built from the Greek words for Friday and thirteen. Some estimates suggest millions of people in the United States feel at least uneasy about the date.

You can see it in everyday design choices:

• Many tall buildings skip a floor labelled 13 and go straight from 12 to 14.
• Some hospitals and hotels avoid room number 13.
• Several airlines leave out row 13 on their seat maps.
• Some people avoid weddings, house moves or surgery on that date, which can make bookings easier for everyone else.

Does the date actually bring more bad luck? The evidence is mixed and mostly reassuring. A small 1993 British study suggested more hospital visits from road accidents on Friday the 13th, but the sample was tiny. A 2008 report from Dutch insurers found slightly fewer accidents and thefts on those days, possibly because nervous people drive more carefully or stay home.

It is not unlucky everywhere

The date only carries weight in some countries. In Spain, Greece and much of Latin America, the unlucky day is Tuesday the 13th. Tuesday was linked to Ares or Mars, the god of war, and Constantinople fell to the Ottomans on a Tuesday in 1453. In Italy, the dreaded date is Friday the 17th, because the Roman numeral XVII can be rearranged into VIXI, Latin for "I have lived," which suggests death.

Symbols of luck travel and change shape just like this. The meaning behind the evil eye symbol shifts across the Mediterranean in a similar way. For more stories of this kind, browse our culture explainers.

One more fact worth knowing: every calendar year has at least one Friday the 13th and never more than three. 2026 has the maximum, falling in February, March and November.

Frequently asked questions

Where did the Friday the 13th superstition come from?

It combines an old fear of the number 13, linked to the Last Supper and the Norse story of Loki, with an old distrust of Fridays. The two were only joined into one unlucky date in the late 19th century. A 1907 novel and later horror films made it widely known.

How often does Friday the 13th happen?

Every year has between one and three Fridays that fall on the 13th. The pattern depends on which day of the week the year starts and whether it is a leap year. In 2026 there are three, in February, March and November.

Is Friday the 13th unlucky in every country?

No. In Spain, Greece and many Latin American countries, Tuesday the 13th is the unlucky date. In Italy people traditionally worry about Friday the 17th instead. The superstition is strongest in English-speaking countries and parts of Europe.