"The car's been running great, knock on wood." Most of us have said it, often while reaching for the nearest table, door frame, or, in a pinch, our own head. It's one of those little rituals we perform almost automatically, even if we'd never call ourselves superstitious.
Here's the short answer: knocking on wood is an old protective tradition meant to avoid "tempting fate" after saying something hopeful or boastful. Nobody knows exactly where it started. Some point to ancient beliefs about spirits living in trees, some connect it to Christian symbolism, and one folklore researcher thinks the modern habit grew out of a children's game of tag.
Theory One: Trees and Fate
Trees have long been linked to luck and fortune. In the pre-Christian beliefs of the Germanic peoples, three figures called the Norns sent fate out into the universe through a great tree. Languages descended from these peoples have expressions like "knock on wood," "touch wood," and, in German, "three times wood."
The ancient Celts, meanwhile, believed that touching wood called on the spirits or gods of the trees. Either way, wood was seen as something with a connection to the forces that shape our luck.
Theory Two: The Cross
Christians have tied the practice to a different kind of wood: the wooden cross of the crucifixion.
Theory Three: A Game of Tag
Here's the surprising one. Folklore researcher Steve Roud suggests the widespread modern habit actually comes from a form of tag called "Tiggy Touchwood." In that game, players were safe from being tagged as long as they were touching wood. Touching wood meant being safe, and the idea may have carried over into everyday speech.
Knocking Around the World
The custom shows up in many countries, each with its own twist. In England, Scotland, and Ireland, people more often say "touch wood" than "knock on wood." In Brazil and Portugal, three knocks are called for after mentioning something bad that might happen. People there don't necessarily believe it works, but it's a polite way of showing you don't want that bad thing to come true.
In Bulgaria, knocking on wood is reserved for protection against evil, and if no wood is handy, people jokingly knock on their own heads. Some follow it by lightly tugging an earlobe. In the Czech Republic, people may knock on wood, glass, or even their own teeth. In Denmark, people say "seven, nine, thirteen" and knock under the table, since those numbers have long been tied to magic.
In Greece and Cyprus, people say "knock on wood" when they hear someone say something negative, to keep it from happening. In the country of Georgia, people usually knock three times when mentioning a bad possibility or after spotting a bad omen.
In Egypt, people say "hold the wood" when mentioning good luck, hoping it will continue. In Iran, people might knock on wood after praising someone, to keep them from being jinxed by the evil eye. And in parts of Indonesia, Malaysia, and Thailand, listeners knock on wood or their foreheads when someone says something unlucky.
So whether it began with tree spirits, a sacred cross, or kids racing around a schoolyard, the habit has clearly stuck. It costs nothing, takes a second, and makes us feel a little better. Here's hoping your luck holds, knock on wood.
