Who is lying? Riddles with answers
Who is lying? In a liar riddle, a few people each say one thing, and you are told how many of them are lying: often exactly one, sometimes all but one. From their words alone, you work out who. Here are 8 original liar riddles with answers, from easy to hard, each answer hidden until you tap to show it. The trick that cracks every one comes first.
The trick: suppose each one is the liar
- Pick someone and suppose they are lying.Everyone else is telling the truth, so treat what they say as fact.
- Look for the one story that breaks.If two of those facts clash, your guess was wrong: try the next person.
- Keep the guess with no clash.Then check it: every honest statement true, the liar’s false.
Two shortcuts save time. When two people say opposite things, one of them is the liar, so everyone else is honest. And when someone says “X is lying”, they are opposites: one honest, one not.
Liar riddles, easy to hard
In these, the riddle tells you how many are lying. Each one is new, written for this page, and checked by trying every possibility: exactly one answer fits.
Riddle 1: Who broke the window? (easy)
A ball came through the greenhouse window, and one of four friends kicked it. Exactly one of them is lying.
- Amy: “Bo kicked it.”
- Bo: “Dev kicked it.”
- Cleo: “It wasn’t me.”
- Dev: “Bo is lying.”
Who is lying, and who broke the window?
Show the answer
Bo is lying, and Bo broke the window.
Amy and Bo can’t both be telling the truth: they name different people. So one of them is the liar, and Cleo and Dev are honest.
Dev is honest, so Bo really is lying. That makes Amy honest: Bo kicked the ball. Check: Cleo didn’t do it, and Bo’s “Dev kicked it” is the one false story.
Riddle 2: Who left the gate open? (easy)
The garden gate was left open and the hens got out. One of three neighbors did it, and exactly one of them is lying.
- Hana: “It wasn’t me.”
- Iris: “It was Hana.”
- Jack: “Iris is telling the truth.”
Who is lying, and who left the gate open?
Show the answer
Hana is lying, and Hana left the gate open.
Hana and Iris say opposite things, so exactly one of them is lying, and Jack is honest.
Jack is honest, so Iris is telling the truth: it was Hana. Hana’s “It wasn’t me” is the lie.
Riddle 3: Who took the last slice of pie? (medium)
Four cousins, one empty pie dish. One of them took the last slice, and exactly one of them is lying.
- Omar: “It wasn’t me, and it wasn’t Priya.”
- Priya: “It was Tess.”
- Tess: “Priya is lying.”
- Uma: “It wasn’t me.”
Who is lying, and who took the pie?
Show the answer
Tess is lying, and Tess took the pie.
Tess says Priya is lying, so one of those two is the liar: if Tess is honest, Priya lies, and if Tess lies, Priya is honest. Either way, Omar and Uma are telling the truth.
So it wasn’t Omar, Priya or Uma, which leaves Tess. Then Priya’s “It was Tess” is true, and Tess’s “Priya is lying” is the lie.
Riddle 4: Who is lying about the lying? (medium)
Nobody did anything this time. Four friends only talk about each other, and any number of them could be lying.
- Kai: “Lena is lying.”
- Lena: “Milo is lying.”
- Milo: “Kai and Lena are both lying.”
- Nora: “Milo is telling the truth.”
Who is lying?
Show the answer
Kai, Milo and Nora are lying. Only Lena tells the truth.
When one person says another is lying, they are opposite: one honest, one a liar. So Kai and Lena are opposites, and so are Lena and Milo, which makes Kai and Milo the same.
Could Milo be honest? Then Kai and Lena would both be liars, but they are opposites, so they can’t both be. So Milo is lying, and so is Kai, the same as him. Lena is the honest one. Nora backs Milo, so she is lying too.
Riddle 5: Who ate the birthday cake? (hard)
Five friends, one cake with a bite out of it. One of them took the bite, and exactly one of them is lying.
- Cora: “It was Dan or Esme.”
- Dan: “It wasn’t Esme.”
- Esme: “Felix is lying.”
- Felix: “It was Cora.”
- Gwen: “Dan is telling the truth.”
Who is lying, and who ate the cake?
Show the answer
Felix is lying, and Dan ate the cake.
Esme says Felix is lying, so one of those two is the liar, and Cora, Dan and Gwen are all honest.
Cora is honest, so it was Dan or Esme. Dan is honest, so it wasn’t Esme. It was Dan. So Felix’s “It was Cora” is false: Felix is the liar, and Esme told the truth. The one who ate the cake isn’t the liar this time.
Only one is telling the truth
Now the other way round: everyone is lying but one. The same trick works if you flip it. Suppose each person is the one honest voice, treat every other statement as false, and see which choice holds together.
Riddle 6: Only one is telling the truth: the last cookie (easy)
Someone ate the last cookie. Three friends were in the kitchen, and this time only one of them is telling the truth.
- Ellie: “Femi ate it.”
- Femi: “I didn’t eat it.”
- Gil: “I didn’t eat it.”
Who ate the cookie, and who is the one telling the truth?
Show the answer
Gil ate the cookie. Femi is the one telling the truth.
Femi and Gil both say “I didn’t eat it”. At most one of them ate it, so at least one of those two is telling the truth. Only one person is, so Ellie must be lying: it wasn’t Femi.
Then Femi’s “I didn’t eat it” is true. He is the one truth-teller, so Gil is lying: Gil ate the cookie.
Riddle 7: Only one is telling the truth: the three tins (medium)
Grandpa hid a cake in one of three tins and gave each tin a label. Only one of the labels is true.
- The red tin: “The cake is in here.”
- The blue tin: “The cake is not in here.”
- The green tin: “The cake is not in the red tin.”
Which tin holds the cake?
Show the answer
The cake is in the blue tin. Only the green label is true.
The red label and the green label say opposite things, so exactly one of them is true. Only one label is true, so the blue label is false: the cake is in the blue tin.
Check: the red label (“in here”) is false, and the green label (“not in the red tin”) is the true one.
Riddle 8: Only one is telling the truth: the missing key (hard)
The shed key is gone, and one of four friends took it. Only one of them is telling the truth.
- Rosa: “Theo took it.”
- Theo: “Lily took it.”
- Lily: “Theo is lying.”
- Ravi: “I didn’t take it.”
Who took the key, and who is the one telling the truth?
Show the answer
Ravi took the key. Lily is the one telling the truth.
Lily says Theo is lying, so exactly one of Lily and Theo is telling the truth. Only one person is, so Rosa and Ravi are both lying.
Ravi is lying, so Ravi took the key. Then Theo’s “Lily took it” is false, so Lily is the one telling the truth, and Rosa’s “Theo took it” is false too.
The same riddle, in pictures
Lie of Sight is a who is lying puzzle with no words to read. Each case is a room seen from above, and each of the Fibberson family says what they saw from where they stood. Exactly one of them is lying. You drag them around the room until every story but one can be true at once. The free Case Files behind each “Now try one in pictures” are a good place to start, and there is a new case every day.
For more in words, try knights and knaves puzzles. For the method on a board, see how to spot the liar, and for three small picture puzzles with their answers, find the liar puzzles.
Questions people ask
How do you solve a who is lying riddle?
Suppose each person is the liar in turn, and treat everyone else’s words as true. If that makes two statements clash, you supposed wrong. The one choice with no clash is the answer.
What if only one person is telling the truth?
Turn the trick around: suppose each person is the one telling the truth, and treat everyone else’s words as false. Look for two statements that can’t both be false: one of those two must be the truth-teller.
Is there a game of who is lying puzzles?
Yes. Lie of Sight has a new find-the-liar case every day, free in the browser: a family each say what they saw in a room, and exactly one of them is lying. You find out who by moving them around.
Ready for today’s case?
A new case every day. Free, with no sign-up to start.