Fan death, red ink and the missing 4th floor: Korean superstitions, explained

You check into a hotel in Seoul. The lift buttons go 1, 2, 3, F, 5. You assume F is a gym, or a food court. It is not. It is the fourth floor, wearing a disguise.

Later, you write your new Korean friend’s name on a birthday card with the only pen you have, a red one, and she goes quiet in a way you can’t decode. That evening, your host warns you, very seriously, not to sleep with the fan on and the door closed.

Welcome to Korean superstitions, or 미신 (mi-sin). Most young Koreans will tell you they don’t believe any of this. Then they’ll quietly avoid the red pen anyway. “I don’t believe it, but why risk it?” might be the most Korean sentence about superstition ever spoken, and it’s the right frame for this whole article: these are habits more than beliefs, and they reveal a lot about history, language and what people worry about.

Here are the big ones, roughly from “almost everyone does this” to “your grandmother does this”.

The number 4: the floor that isn’t there

In Korean, the number four (사, sa) sounds exactly like the Sino-Korean character for death (死, also sa). The same is true in Chinese and Japanese, which is why the “unlucky four” runs across East Asia.

In Korea, this shows up as:

Elevators labeled F instead of 4. Common in older apartment buildings, hospitals and some hotels. Some buildings skip the number entirely and go straight from 3 to 5.
Hospitals avoiding room 4s, for obvious reasons. Nobody wants to be wheeled into the death room.
Gift sets and money in fours avoided. You won’t usually give four of something as a gift, and wedding and funeral envelopes avoid amounts with a 4, like 40,000 won (see Korean wedding money).

Many newer buildings now just use 4 like normal, and younger Koreans may shrug at it. But “F” in the lift is still a classic tourist discovery.

Never write someone’s name in red

This is the one even skeptical Koreans tend to follow. Writing a living person’s name in red ink is considered deeply unlucky, as if you’re wishing them dead. Teachers use red for corrections, of course, but they won’t usually write a student’s name in red. If you write your own name in red on a document, someone may gently slide a black pen towards you.

Where does it come from? There are several stories, and the National Folk Museum of Korea has looked into them. The custom is often linked to the practice of writing the names of the dead in red, for example on registers or memorial items, and to Chinese traditions in which red was the color of emperors and certain names could not be written in it. Whatever the origin, the effect today is simple: red ink + a living person’s name = a small social shock. Use black or blue for names on cards, forms and whiteboards.

Fan death: Korea’s most famous urban legend

Ask anyone who’s lived in Korea about superstitions, and fan death comes up within thirty seconds.

The belief: if you sleep in a closed room with an electric fan running, you might die. Explanations vary: the fan uses up the oxygen, it chills you to hypothermia, it causes suffocation by moving the air too much. Electric fans sold in Korea have long come with timers that switch them off after a set time, and for years news reports in hot summers carried warnings about fans in closed rooms, which helped the idea spread.

Scientifically, there’s no good evidence that a fan in a closed room can kill a healthy person, and the “eats the oxygen” theory doesn’t hold up at all. Reuters and others have written about how the belief persisted anyway. Today, many younger Koreans treat fan death as a joke and a meme, the way people elsewhere treat “don’t swim for an hour after eating”. But you’ll still meet a parent or grandparent who props a door open “just in case”, and the timer knob stays.

Say / Mean: 선풍기 틀고 자면 죽어! (“If you sleep with the fan on, you’ll die!”) from an older relative usually means “I worry about you”, not “I’ve reviewed the medical literature”. The best answer is a smile, a nod and the timer set to 1 hour.

Exam superstitions: seaweed soup and sticky taffy

Korea’s exam culture is intense, so it’s no surprise the exam superstitions are the most active ones. In the run-up to the national university entrance exam, the 수능 (su-neung), you’ll see them everywhere.

No seaweed soup on exam day. 미역국 (mi-yeok-guk), seaweed soup, is slippery, and the Korean phrase for failing an exam is literally “to slip” (미끄러지다). Eating it before an exam is like inviting yourself to slip. (Which is awkward, because seaweed soup is also the traditional birthday soup. Students born on exam day have a tough choice.)
Sticky taffy and rice cakes for luck. 엿 (yeot), a chewy Korean taffy, and 찹쌀떡 (chap-ssal-tteok), sticky rice cakes, are given to students because they “stick”. The phrase for passing is “to stick” (붙다), as in “to stick to the university”. On exam day, parents and juniors sometimes stick yeot onto school gates. (Warning: 엿 먹어, “eat yeot”, is also a rude insult. Context is everything.)
Forks and mirrors. Some gift sets include a fork, so you “pick” the right answer, or a little mirror, so you “see” the answers well. These are puns more than beliefs, and they make lovely, slightly ridiculous gifts.
No haircuts, no shaving. Some students avoid cutting their hair before a big exam so they don’t “cut” their luck.

Do students really believe? Mostly not. But in a week when a whole country lowers its voice (on exam day, flights are rescheduled during the listening test), nobody wants to be the one who ate the seaweed soup.

Dreams: pigs, poo and lottery tickets

Koreans take some dreams surprisingly seriously.

Pig dreams (돼지꿈) mean money. The pig is a symbol of wealth and luck, because the Chinese character for pig (豚) sounds like the Korean word for money (돈, don). Dream of a pig, and you buy a lottery ticket the next day. Some people even try to buy a good dream from a friend, which is a sentence that makes perfect sense in Korean.
Poop dreams are lucky too. Yes, really. Dreaming about stepping in poop, or being covered in it, is read as a sign of incoming money. Korean dream logic is beautifully strange.
Conception dreams (태몽, tae-mong). Traditionally, a dream that foretells a pregnancy, often featuring a tiger, a dragon, a fruit, a snake or a jewel. The Encyclopedia of Korean Culture describes how people interpreted these dreams to predict a baby’s nature or even sex. Many Korean adults can tell you their own 태몽, as told by their mother. (“Your mother dreamt of a huge peach, that’s why you’re so sweet.”) If a Korean friend says someone dreamt of a dragon, they may be politely announcing a pregnancy.
Teeth falling out in a dream is a bad omen, sometimes linked to bad news in the family.

Small daily superstitions

Don’t shake your leg. Jiggling your leg while sitting is said to shake your luck (or your wealth) away. Grandparents will tap your knee. Mostly, it’s just a manners thing wearing a superstition costume.
Don’t whistle at night. It’s said to call ghosts or snakes. In a quiet Korean apartment, it might also call your downstairs neighbor.
Don’t cut your nails at night. An old folk tale says a mouse could eat the clippings and turn into you. (Science has yet to confirm. The practical origin is likely darkness plus sharp blades in the old days.)
Don’t give shoes to your partner. Shoes as a gift mean they’ll “walk away” from you. Clever couples get around it by having the partner pay a token coin for the shoes, so it becomes a “purchase”, not a gift.
Don’t step on the threshold. Older Koreans say stepping on a door threshold brings bad luck.
Black cats and crows have bad reputations, while magpies are good news: a magpie singing in the morning means a visitor or good news is coming.

Fortune telling: still big business

Superstition’s grown-up cousin in Korea is fortune telling, and it’s very much alive. Koreans visit fortune tellers (점집) or saju cafés to have their 사주 (sa-ju), “four pillars” of birth year, month, day and hour, read, especially before big decisions: a wedding date, a business opening, a move, a new year. Many people also check 궁합 (gung-hap), the compatibility of two people’s birth charts, before marriage. Today there are apps, online saju services and tarot cafés on every university street.

Most people treat it as entertainment with a dash of hope, or as a kind of counseling. But if a Korean friend says “I went to get my saju read and it said this year I should avoid water”, don’t laugh too hard. Maybe just skip the beach trip together.

(Korea’s love of sorting people by blood type and MBTI is a related story. We’ll get to that one.)

Why superstitions stick around in a high-tech country

Korea is one of the most connected, educated societies in the world, so why do these habits last?

Language makes them memorable. Many Korean superstitions are puns: four sounds like death, sticking means passing, slipping means failing, pig sounds like money. Puns are hard to forget.
They’re about care. Most of these are said by parents and grandparents to protect someone they love, especially before exams, weddings and births.
Low cost, possible benefit. Avoiding seaweed soup for one day costs nothing. If it might help, why not?
They’re fun. Pig dreams and lottery tickets, yeot on the school gate, couples paying 100 won for shoes: these are rituals people enjoy sharing.

What visitors should actually do

Use black or blue ink for people’s names. This one matters most.
Don’t give gifts in fours, and avoid 4 in money envelopes.
Skip seaweed soup jokes around students in exam season. Give yeot or chocolate instead.
Treat fan death with a smile. If your host is worried, crack the door open.
Don’t buy your partner shoes without the coin trick.
Have fun with dreams. If you dream of a pig, tell your Korean friends. They may ask to buy the dream.

None of these will offend anyone if you get them wrong once. But knowing them shows you’ve noticed the small, funny, very human logic that runs underneath Korean daily life. And if you find yourself, one day, quietly reaching for a black pen to write a friend’s name, congratulations: you’ve caught it.