11 of History's Toughest Riddles

Test your brain.
Test your brain. / izusek/Getty Images (woman); ahmad agung wijayanto/Shutterstock (question marks)

Test your brain with these tough riddles and brainteasers. If you're stumped, scroll to the bottom for the answers.

1. A Hobbit Head Scratcher

Anyone who’s gotten lost in Middle-earth knows that J.R.R. Tolkien loved a logic puzzle. The riddle competition between Bilbo Baggins and Gollum in The Hobbit serves up several mind-bending morsels, the trickiest of which might be:

Voiceless it cries, wingless flutters, toothless bites, mouthless mutters.


2. The Mad Hatter's Dirty Trick

One of the most famous literary riddles in literature is also the most frustrating ... because it came without an answer! In Alice's Adventures in Wonderland, the Mad Hatter poses this puzzle to Alice:

“Why is a raven like a writing desk?”

The Mad Hatter

3. Oedipus's Complex Problem

In Sophocles’s Oedipus Rex, the title character must answer to the Sphinx to save his own life and continue his journey to Thebes. Spoiler: he nails it. The monster asks

What walks on four feet in the morning, two in the afternoon, and three at night?

The Sphinx

4. A Harry Potter Puzzler

The Harry Potter series is teeming with playful language and cleverness, so it’s only right that a juicy riddle made its way into the series. In The Goblet of Fire, J.K. Rowling gives a nod to the Sphinx by putting one in the maze during the Triwizard Tournament. Harry is tasked with cracking this puzzle:

First think of a person who lives in disguise, who deals in secrets and tells naught but lies. Next tell me what’s the last to mend, the middle of middle and the end of end. Finally give me the sound often heard during the search for a hard to find word. Now string them together and answer me this, which creature are you unwilling to kiss?

The Sphinx

5. Guarded Truths

The riddle was coined by mathematician Raymond Smullyan and goes by many names—“A Fork in the Road,” “Heaven and Hell,” and “The Two Doors,” among them. It is probably most well known for having a role in the 1986 movie Labyrinth. Here’s the basic idea: You’re met with a choice between two identical doors with an identical guard at each. One door leads to heaven and one door leads to hell. You can ask one guard one question and then make your choice on which door to pass through. One of the guards always tells the truth and one of them always lies. So, what question do you ask? 

6. A Bully Riddle

This riddle was rumored to be Teddy Roosevelt’s favorite:

I talk, but I do not speak my mind I hear words, but I do not listen to thoughts When I wake, all see me When I sleep, all hear me Many heads are on my shoulders Many hands are at my feet The strongest steel cannot break my visage But the softest whisper can destroy me The quietest whimper can be heard.

7. James Joyce Goes Deep

James Joyce
James Joyce. / Heritage Images/GettyImages

In Ulysses, Stephen Dedalus poses a riddle to his pupils. A word to the wise: Don’t spend too much time trying to work this one out. 

The cock crew The sky was blue: The bells in heaven Were striking eleven. Tis time for this poor soulto go to heaven.

Stephen Dedalus

8. The One that Started It All

There is debate over who wrote the first riddle, but the ancient civilization of Sumer is certainly responsible for one of them. Sumerians’ contribution to the legacy of logic problems:

There is a house. One enters it blind and comes out seeing. What is it?

9. Think Hard

Another oldie-but-goodie originated in 18th-century England, though you might know it from Die Hard with a Vengeance.

As I was going to St Ives, Upon the road I met seven wives; Every wife had seven sacks, Every sack had seven cats, Every cat had seven kits: Kits, cats, sacks, and wives, How many were going to St Ives?

10. Plato's Ancient Head-Scratcher

In The Republic, the philosopher Plato references a famous Greek riddle credited to someone named Panarces:

There is a story that a man and not a man Saw and did not see a bird and not a bird Perched on a branch and not a branch And hit him and did not hit him with a rock and not a rock.


11. Einstein's Fishy Puzzle

Albert Einstein
Albert Einstein / Doreen Spooner/GettyImages

The so-called “Eistein’s Riddle” asks a simple question: “Who owns the fish?” It may not have been written by Einstein—sometimes it’s attributed to Lewis Carroll, and it’s highly likely that neither of them wrote it at all. Occasionally, some versions feature other animals, like zebras, instead of fish. But regardless of its origins, this riddle is a tough one:

Here’s the set-up:

There are 5 houses in five different colors. In each house lives a person with a different nationality. These five owners drink a certain type of beverage, smoke a certain brand of cigar and keep a certain pet. No owners have the same pet, smoke the same brand of cigar or drink the same beverage. The question is: Who owns the fish? These are your hints: The Brit lives in the red house The Swede keeps dogs as pets The Dane drinks tea The green house is on the left of the white house The green house's owner drinks coffee The person who smokes Pall Mall rears birds The owner of the yellow house smokes Dunhill The man living in the center house drinks milk The Norwegian lives in the first house The man who smokes blends lives next to the one who keeps cats The man who keeps horses lives next to the man who smokes Dunhill The owner who smokes BlueMaster drinks beer The German smokes Prince The Norwegian lives next to the blue house The man who smokes blend has a neighbor who drinks water.

the word 'answer' in a blue text bubble
Justin Dodd/Mental Floss

1. The wind

2. The Hatter doesn’t have the answer, and as it turns out, Carroll didn’t, either. But readers’ desire for closure was so intense that the author was forced to dream up an answer that later appeared in a preface:

Enquiries have been so often addressed to me, as to whether any answer to the Hatter's Riddle can be imagined, that I may as well put on record here what seems to me to be a fairly appropriate answer, viz: 'Because it can produce a few notes, tho they are very flat; and it is never put with the wrong end in front!' This, however, is merely an afterthought; the Riddle, as originally invented, had no answer at all.”

Lewis Carroll

3. “Man: as an infant, he crawls on all fours; as an adult, he walks on two legs and; in old age, he uses a 'walking' stick.” 

4. A spider.

5. In Labyrinth, the protagonist (Sarah, played by Jennifer Connelly) gets it right. She asks the one on the left, “Would he [referencing the guard on the right] tell me that this door leads to the castle?” Leftie tells Sarah yes, and from there, she is able to conclude that he is the one guarding the door to “certain death.” This can get tricky to work through, but luckily the internet has an unending supply of resources if you want a deep dive into the puzzle’s logic.

6. An actor 

7. “The fox burying his grandmother under a hollybush.” 

Get it? Dedalus’s students don’t, and many scholars believe that’s sort of the point. The exaggerated difficulty is meant to be a kind of riddle about riddles. However, not all of James Joyce’s riddles in Ulysses are impossible. Protagonist Leopold Bloom jokes, "Good puzzle would be cross Dublin without passing a pub.” This equally baffling head scratcher was solved by a software developer in 2011. The programmer managed to map all of Dublin’s pubs and used an algorithm to chart a course that never comes within 115 feet of one.

8. A school

9. One. As John McClane learns, this is a classic trick question. If the narrator meets the group on the way to St. Ives, then they must be going in the opposite direction and the math calculations are simply a bit of trickery meant to misdirect.

10. “A eunuch who did not see well saw a bat perched on a reed and threw a pumice stone at him which missed,” according to Plato. You can be forgiven for not coming up with that off the top of your head. In Greek, the verb for “to hit” can also indicate throwing something with the intention of hitting it.

11. The German. Here's an explanation.

A version of this article originally ran in 2017; it has been updated for 2022.