# Questions tagged [liars]

Puzzles that focus on getting information from truth-tellers (who never lie), liars (who always lie), and/or Jokers (who answer at random), or which use such characters as an integral part of the puzzle.

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### Two persons and one question "Is the shaman honest". Which one of them is the shaman?

An anthropologist arrived to the shaman's den where there were two persons, one with a green hat and one with a blue hat. One of the shaman's students had said that there was a Star Predictor with the ...
506 views

### Smullyan Logic Puzzle about Nelson Goodman Principle - Knights and Knaves

In Smullyan's "Logical Labyrinths" there is the following problem 1.11: ...
346 views

### Constructing an island according to rules in Smullyan's "What is the Name of this Book"

I've recently finished dropping my jaw at Raymond Smullyan's "What is the Name of this Book," and the section on Gödel's incompleteness theorem, involving islands of knights (truthers) and knaves (...
478 views

### What is the smallest number of lies needed to solve a Dragon Joust puzzle?

I recently watched this video which presents a deduction "riddle" about dragon jousting. The rules for the puzzle (from the video) are as follows: After centuries of war, the world’s ...
752 views

282 views

### The scales never lie (oh yes they do!)

There are $10$ coins, one of which is a fake, and weighs either more or less than the others - you don't know which. There are two sets of scales - one tells the truth, the other lies (always says ...
4k views

### 2 Guards, 3 Keys, 2 Locks

There are 2 guards: one only tells the truth, the other only lies. There are 2 locks and 3 keys: each lock can only have 1 key matched - the 3rd key doesn't do anything. You can only ask one ...
363 views

### Knights and knaves puzzler

A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet three inhabitants: Peggy, Joe and Zippy. Peggy claims, "I am a knight or ...
330 views

### Knight and knaves

A very special island is inhabited only by knights and knaves. Knights always tell the truth, and knaves always lie. You meet three inhabitants: Alice, Rex and Bob, where Alice tells you that "Rex is ...
582 views

### Island of Knights, Knaves, Spies

There are 3 types of inhabitants of a village: knight, knaves, normal. You should map each inhabitant with its type, by asking only this type of question to a person: "Hey X, what is the type of ...
85 views

### Survive from death by asking the right question twist [duplicate]

You are at a path and there is two roads splitting from it. The first one is certain death and the other is the way home. You do not know which way is the right way home, but there are two people. ...
5k views

### Knights and Knaves: What does C say?

You are on a fictional island with two types of people: knights who always tell the truth, and knaves, who always lie. Three of the inhabitants - A, B, and C are standing in the garden. A says, "B and ...
3k views

### Time to call the bluff [closed]

You are located outside of two rooms which have a door between them. Each room has one or more computers whose total power is unknown, so they cannot be reliably used as proof-of-work to compare times,...
4k views

### Ask one verbal question to figure out who is blind and who is mute among three persons

This is another "You can ask only one question" puzzle. This is an edited very restricted version There may be multiple answers but I could come up with only one. There are three persons in three ...
314 views

### Knights and Knaves on a (Not So) Deserted Island

One day, while flying your single-engine seaplane out over the Pacific, the electrical system shorts out, all of your electrical systems (including the radio) fail, and the engine dies. You are in a ...
261 views

### The chariot race

In a chariot race only 4 cars came to the finish: the blue, the green, the red and the white one. Titus, who is in bed with a cold, inquires to Quintus about the outcome of the race, because he ...
4k views

### The joke office

Alice and Bob are supposed to get form A at the joke office. Forms A, B, C, D and E are each at exactly one of the following five terminals. At one Terminal is only one form. Terminal 1: Here ...
782 views

### The alcoholic village festival

The villages Arriba and Abajo together have 2019 inhabitants. At the annual festival are more than 2000 villagers this year. When they form a huge circle for dancing, everyone calls happy: ...
3k views

### Robots in a spaceship [duplicate]

Xerxes has 6, 7 and 8-arm robots in his spaceship. Unfortunately, the 7-arm robots are misprogrammed and everything they say is a lie. The other robots are fine, they always speak the truth. Once ...
616 views

### Simple logic puzzle [duplicate]

We think of an island inhabited by rogues and knights. Rogues are always lying, knights always speak the truth. One day 12 islanders come together among which is at least one knight and at ...
2k views

### The warming up game

The theater group began today with a warming up game. Everyone has been assigned a role and is now either a bad guy who always lies, or a good guy who always tells the truth. Max, who comes late, ...
772 views

### Six liars, truth-tellers and jokers

As in this puzzle, there are three different kinds of people: truth-tellers (always telling the truth), liars (always lying) and jokers (who may either tell the truth or lie). Based on these aspects ...
451 views

### Liars, truth-tellers and jokers

In a strange village there are three kinds of persons: knights (always telling the truth), knaves (always lying) and jokers (who may either tell the truth or lie). A, B, C and D live in this village, ...
667 views

### Three knights or knaves, three different hair colors

In a group of three people (A, B and C), everyone has a different hair color (blond, black or brown, not necessarily in this order) and everyone may be either a knight (always telling the truth) or a ...
310 views

### Four Doors, One Escape

You are trapped in a room with four adjacent doors upon a wall. On each door is one of the first letters of the alphabet, in order, from left to right. You know that one of the doors leads to freedom, ...
407 views

### Lying under arrest

I'm in a custody, under arrest, no contact with the outside world. I do not know if in that jurisdiction authorities are allowed to lie. Some real-world knowledge suggest lying by authorities is ...
169 views

### The truth within

Someone living in the remote cabin that you do put a virus onto your PC. Here are your suspects: Your brother, Liam, who only tells the truth about his opinions. Your sister, Irene, who tells the ...
2k views

### Island of Knights, Knaves and Spies

There is an island with $N$ inhabitants (for example $A_1, A_2, \dots, A_N$), each of them is either a knight, a knave, or a spy. As usual: knights will always tell the truth upon answering a ...
439 views

Evelyn, Skylar, Alayna, Madelyn, Jonathon, Lara, Alyin, Felix, Iris, Bob and Roslina live on an island where some people always tell the truth, and the rest always lie. Roslina says "Alyin and Evelyn ...
9k views

### 3 doors, three guards, one stone

You are in a room with three doors. Behind two of them, the darkest pit of hell waits for you to make a mistake. The other door leads to heaven and freedom. Each door is guarded by a guard: Michael, ...
1k views

### Island of Liars

A king goes to an island, where there are 5823 people who always tell the truth and 8723 who always lie. The king is special guest for the party celebrating 2053 year. On the party, liars and ...
8k views

### Possible answer to the Heaven Hell Door riddle

There is a fairly common riddle You're standing between the door to heaven and the door to hell. A guard stands by each door. One guard always tells the truth, and the other always lies. You don't ...
443 views

### Brain twister. A simple riddle to play [duplicate]

You are lost big crowded (monster). There are only two human living Jacobe and Recode . Your task is to reach your home, there are two routes and you are confused. Conditions: Jacobe always tell the ...
131 views

### Five possible liars - any way to solve with a grid-based method?

The situation is as follows: At a semiconductor laboratory in Hsinchu a security guard caught five technicians accessing a high level security area reserved for the most trusted scientists working in ...
126 views

### who eats more fruits? [closed]

in a party 3 brothers discussing: first brother says " I ate more fruit than 2nd brother and 2nd brother ate more fruit than 3rd brother" 2nd brother says " 3nd brother ate more than me also 3rd ...
728 views

### Monty's Labyrinth

(A fun combination of two classic puzzles, hope seasoned puzzlers enjoy.) Having escaped through almost all of a labyrinth, you are met by three magical doors. Two of them lead to certain and ...
3k views

### Classic two guards and two doors

I recently heard a version of the classic two guards (one is a knight who always tells the truth and the other is a knave who always lies) standing by two doors (one leads to certain death and the ...
893 views

### The Three Mystery People- An Actual Mystery

I believe almost everyone has heard this riddle before. There are three people in front of you. One always tells the truth, one always lies, and one answers randomly between truth and lies. You ...
1k views

### yes/no logic problem

There is a truth teller (always tells the truth), a liar (always lies), and one that sometimes answers truthfully and sometimes lies. Each person knows who is who. You may ask three yes or no ...
816 views

### Murder in the Royal Court

An entry in Fortnightly Topic Challenge #40: Retrograde Analysis! I can't believe it! Last night we heard a bit of fighting... but we had no idea that... our King was in check, and my fellow Rook and ...
269 views

### Truth tellers or liars among two people

Two guys, number One and number Two. You ask number One "Is there a truth-teller among you?". He replies and you have the answer to your question. What is number One and what is number Two?
380 views

### Fami-liar Situation

Exactly one of Sam or Tom has family visiting. They make these statements: Sam: "Tom has family visiting, but I don't." Tom: "Sam is lying, or I am lying, or possibly we're both lying.&...
460 views

### Classic 2 Guards But With 3 Doors Instead

So the rules are almost the same : You get to ask just one question to whichever guard you want to (just 1 guard; asking both guards is not allowed) There are 2 guards, one tells the truth and ...
162 views

### A Tournament to Remember

The King: Recently we had a big tournament, worth being immortalized in the chronicles of my kingdom. Unfortunately, the court scribe misplaced the record of the final event, and we need to restore it....
358 views

### Riddle Again, Riddle Again, What am I? [closed]

1. If a chicken says, "All chickens are liars" is the chicken telling the truth? 2. A man is traveling to a town and comes to a fork in the road. If he goes left, he goes to the liars' village....
441 views

### A Space Station 13 malfunctioning A.I

Disclaimer: It is not necessary to read the previous puzzle, or the one before even if it continues on the same story. The current puzzle is a different one which can work as a pure standalone. ...
425 views

### Tell the truth Puzzle [duplicate]

There are three people (Ajay, Bhuvi and Chandu), one of them is a Gun, one a missile, and one a robot. The Gun always tells the truth, the missile always lies, and the robot can either lie or tell the ...
894 views

### A Space Station 13 complicated escape

After successfully resolving this tricky situation, you, the Captain of the Space Station 13, have ordered what remains of your crew to gather in the escape shuttle. Accompanied by the Security ...