Knights & Knaves
Classic truth-teller and liar logic puzzles.
The rules
How to play
- 01
The island
Every character you meet is either a Knight or a Knave — there is no one in between.
- 02
Knights tell the truth
A Knight's every statement is true, without exception — take their words at face value.
- 03
Knaves always lie
A Knave's every statement is false, without exception — the opposite of what they say holds.
- 04
Read the statements
Each islander makes one or more claims about themselves or the others. Those claims are your only evidence.
- 05
Deduce each type
Work out, by pure logic, whether each character is a Knight or a Knave. A proper puzzle has exactly one consistent answer.
Play smarter
Four ways to reason it out
Assume and test
Pick a character, assume they are a Knight, and follow the consequences until it holds or breaks.
Hunt contradictions
If an assumption forces an impossible situation, the opposite must be true.
The self-reference rule
Nobody can say "I am a Knave" — it is impossible for either type, so such a claim never appears.
"Same type" statements
"We are the same type" is true when the speakers match and false when they do not — a shortcut once you have one answer.
Watch & learn
Two minutes to mastery
From the Intel desk
Reading for the curious
Knights and Knaves Puzzle: A Complete Beginner's Guide to Truth Puzzles
Learn how to solve Knights and Knaves logic puzzles from scratch. Master the rules of this classic truth-teller and liar puzzle, follow our visual tutorial, and discover essential strategies created by Raymond Smullyan.
Knights and Knaves Strategies: Advanced Logic Techniques from Math Olympiads
Master advanced knights and knaves strategies including the contradiction method, truth table analysis, and techniques from math olympiad logic problems. Learn how to solve hard knights and knaves puzzles like a competition mathematician.
Keep going
Where to next
Fresh every day
The Daily Knights & Knaves
One shared deduction for everyone, every day. Build a streak and compare your solving time.
Go deeper
Rules & strategy guide
From assume-and-test to the self-reference rule — the complete written guide with a worked example.
Beyond the island
Explore all puzzles
Sudoku, Nonograms, Kakuro and sixteen more logic games await.