They say a little superstition never hurt anyone, especially when it comes to avoiding jinxing a stroke of good luck. The phrase “knock on wood” is like the trusty umbrella of superstitions—no one really wants to get caught in a downpour of bad fortune.
This quirky tradition has people rapping their knuckles on the nearest wooden object, believing it will ward off misfortune or ensure a positive outcome continues.
But here’s the plot twist that would make any folklore detective do a double-take: despite all the ancient stories you might have heard about tree spirits and Celtic druids, the actual documented history of “knock on wood” is surprisingly recent—and possibly much more mundane than you’d expect.
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Knock on Wood Origins
The Oxford English Dictionary’s first record of the phrase “knock on wood”—meaning to knock on something made of wood as a superstitious action to ward off misfortune or bad luck—isn’t until 1907 (a slightly earlier version “touch wood” appeared in 1898).
That’s right—despite all the dramatic tales of ancient pagans communing with tree spirits, we have zero written evidence of this practice before the late 1800s.
Michael Adams, professor of English and linguistics at Indiana University Bloomington, is skeptical of the conventional wisdom behind ancient origins.
As he points out, just because something feels ancient doesn’t mean it actually is.
Sometimes a superstition that seems to have emerged from the mists of time actually started when your great-great-grandmother was already alive and complaining about “kids these days.”
Competing Knock on Wood Origin Stories
Theory #1: Ancient Tree Whisperers
The most popular origin story goes something like this: Ancient pagan cultures such as the Celts believed that spirits and gods resided in trees.
Knocking on tree trunks may have served to rouse the spirits and call on their protection, but it could have also been a way of showing gratitude for a stroke of good luck.
Many scholars believe the expression “knock on wood” is rooted in pagan rituals to ward off evil spirits.
“Early Celtic and Germanic peoples believed trees housed spirits or gods and had stories about them,” says etymology expert Jess Zafarris. “Touching wood could call on the spirits for protection or be an ‘expression of thanks’ that would bring good luck.”
It’s a compelling narrative that taps into our love of mystical ancient wisdom. The problem? Folklorists have only found reference to [knocking on wood] starting in the early 20th century.
There’s simply no documented evidence connecting modern wood-knocking to ancient tree worship.
Theory #2: Christian Cross Connection
Another theory suggests that touching wooden objects—particularly the wood of the cross from Christ’s crucifixion—was seen as a gesture of faith and divine protection.
According to Zafarris, “There’s been speculation that it has a connection to Christianity, though that’s probably a retcon,” or an instance of recontextualizing.
Like the pagan theory, this one sounds plausible but lacks historical documentation linking medieval Christian practices to our modern habit of frantically searching for the nearest table leg.
Theory #3: The Playground Plot Twist
Here’s where things get interesting. British folklorist Steve Roud traces the practice to a 19th century children’s game called “Tiggy Touchwood,” a type of tag in which players were immune from being caught whenever they touched a piece of wood such as a door or a tree.
In his book The Lore of the Playground, Roud makes a bold claim: “Given that the game was concerned with ‘protection,’ and was well known to adults as well as children, it is almost certainly the origin of our modern superstitious practice of saying, ‘Touch wood.’ The claim that the latter goes back to when we believed in tree spirits is complete nonsense.”
This theory has the advantage of actually being documentable. Children’s games from the 19th century are much better recorded than hypothetical ancient rituals, and the concept of touching wood for “safety” in tag games directly parallels our modern superstitious use.
The Academic Consensus (Or Lack Thereof)
In A Dictionary of English Folklore, scholars Jacqueline Simpson and Steve Roud note that the earliest known reference to the practice only dates to 1805. That’s it—1805. Not 500 BCE, not medieval times, but the same century that gave us the steam locomotive and Napoleon’s final defeat.
Of course, much folklore is learned informally, by word of mouth or customary behavior. So it’s possible – even likely – that the phrase and the ritual predate its first appearance in print.
But the complete absence of earlier documentation is telling, especially when compared to other superstitions that do have ancient written records.
How Other Countries Knock on Wood
Despite its possibly recent origins, “knock on wood” has spread worldwide and spawned fascinating variations:
- In Egypt, “emsek el-khashab” (“hold the wood”) is said when mentioning either good luck one has had in the past or hopes one has for the future.
- In Italy, “tocca ferro” (“touch iron”) is used, especially after seeing an undertaker or something related to death.
- Turkish people often pull on one earlobe and knock on wood twice to ward off a jinx.
- In Denmark the saying is “7, 9, 13” (usually accompanied by knocking under a table), as these numbers have traditionally been associated with magic.
Why We Still Knock on Wood Today
So why does a possibly 200-year-old children’s game rule our anxiety responses today?
Wood holds deep symbolic meaning across various cultures. As a natural element, it represents life, growth, strength and connection to the earth.
“Trees are entirely tied up with notions of life and death and rebirth and fate and the divine,” says Zafarris.
Whether or not our ancestors actually knocked on trees to summon spirits, the symbolism resonates with something fundamental in human psychology.
We want to feel like we have some control over fate, and a simple rap on a wooden surface gives us that psychological comfort.
Wrapping it Up
I’d wager few, if any, people today think – after saying something that might bring bad luck – “I’d better ask the tree spirits for help!”
Instead, we’re probably unconsciously recreating the safety mechanism from a Victorian-era children’s game, elevated to the status of protective ritual through repetition and cultural transmission.
The irony is all there: our most “ancient” superstition might actually be younger than the telephone.
But perhaps that’s fitting for a practice that’s fundamentally about managing uncertainty.
In a world where we’ve replaced tree spirits with smartphones and ancient wisdom with Wikipedia, we still find ourselves reaching for the nearest wooden surface when life feels a little too good to be true.
After all, whether you’re invoking Celtic druids or just following the rules of Tiggy Touchwood, the message is the same: sometimes the most logical thing to do is something completely illogical—like rapping your knuckles on the nearest piece of timber and hoping for the best.
Sources
- Adams, Michael. Professor of English and linguistics at Indiana University Bloomington. Interview with Reader’s Digest, May 16, 2025.
- Andrews, Evan. “Why Do People Knock on Wood for Luck?” History.com, August 29, 2016.
- “Knocking on wood.” Wikipedia, May 20, 2025.
- Roud, Steve. The Lore of the Playground: The Children’s World – Then and Now. Random House, 2010.
- Simpson, Jacqueline, and Steve Roud. A Dictionary of English Folklore. Oxford University Press, 2000.
- “What Are the Origins of ‘Knock on Wood’?” Reader’s Digest, July 20, 2021.
- “Why We Knock on Wood, and the Origins of 7 Other Superstitions.” Interesting Facts, August 7, 2024.
- Zafarris, Jess. Etymology expert, founder of Useless Etymology. Interview with Reader’s Digest, 2021.