Korean Superstitions: Red Ink, Fan Death, and the Missing 4th Floor

Every country keeps a set of small rules that nobody can fully explain, and Korea is no exception.

Don’t write a name in red. Don’t give shoes as a gift.

Don’t eat seaweed soup the morning of a big exam. These beliefs are called 미신 (superstition), and even people who laugh at them tend to follow them anyway — which means the vocabulary around them comes up in ordinary conversation far more often than you would expect.

Red ink and the names of the dead

The most famous rule is also the easiest to break by accident: red ink is reserved for the names of the dead, so writing a living person’s name in red reads as a small curse. Sign a birthday card in red and someone will absolutely say something.

재수 없다 literally means to have no luck, but in casual speech it swings much harder — closer to calling something or someone unpleasant. That double life is typical of superstition vocabulary in Korean: half of it has drifted into everyday slang.

The floor that is not there

Step into an older elevator and you may find F where 4 should be.

The Sino-Korean number four, 사, is a homophone of the character for death, so buildings quietly avoid it.

Hospitals and older apartment blocks are the most likely places to see it.

The same logic reaches beyond elevators. Phone numbers and license plates heavy with fours are less popular, and some hospitals renumber wards to avoid the digit entirely.

Nobody treats it as a serious danger — it is closer to the way a Western hotel quietly labels a floor 12A.

If you want to get comfortable with the underlying counting system that makes the pun work, the Korean numbers guide walks through the Sino-Korean set where 사 lives.

Exam-day rules: soup, sticky snacks, and slipping

Korean exam superstitions are built almost entirely on wordplay. 미역국 is slippery, and the verb for slipping is also the verb for failing a test — so the soup is out on exam morning.

Sticky snacks, meanwhile, are in, because the verb for sticking is the verb for passing.

The polite thing to say to someone before a test is 시험 잘 보세요 (do well on your exam) — never anything involving slipping. Food words like these turn up constantly in daily conversation too, and the Korean food vocabulary list covers the wider set.

Fans, whistles, and gifts you should not give

Two more classics round out the list. The first is the country’s most exported piece of folklore: the idea that sleeping in a closed room with an electric fan running can be dangerous. It is a myth with no medical basis, and these days most people bring it up as a joke rather than a warning.

Whistling at night was said to call snakes or ghosts, and shoes make a bad gift for a romantic partner because the receiver might walk away in them.

Notice the ending in 안 된대요 — the -대요 form reports what other people say, which is exactly how superstitions get passed along in Korean.

You will hear it framed that way almost every time: not “this is true,” but “they say.”

Folklore vocabulary also overlaps heavily with Korea’s summer ghost-story tradition, and Korean summer horror words picks up where this list leaves off. None of these beliefs are things you have to adopt, but knowing them explains a surprising number of small moments — the pen someone swaps out, the elevator button that is missing, the breakfast a friend refuses on the morning of a test.