The caballero, the escudero and the spy

1. Don't try to classify someone just by whether their statement is true or false: the spy can do either.
2. C's sentence is very restrictive: if C were a knight, he would directly set A's role.
3. Try what happens if A were not a squire. The other two phrases no longer fit with a single knight, a single squire and a single spy.

Answer: - A is the squire.

• B is the spy.
• C is the gentleman. Let's see it without jumps. C says: “A is a knave.” If C is a knight, that sentence is true, so A is a knave. Since we already have a knight and a squire, B remains as a spy. We then check the three sentences: - A says: “B is a gentleman.” It is false, and A is knave: it fits.
• B says: “A is a gentleman.” It's fake, but B is a spy: he can tell the truth or lie, so it fits.
• C says: “A is a knave.” It's true, and C is a gentleman: it fits. Now we rule out that there is another solution. A cannot be a knight, because then his sentence “B is a knight” would be true and there would be two knights: A and B. A can't be a spy either. If A were a spy, B and C would remain as knight and squire. But B says “A is a knight,” which would be false, so B could not be a knight; I would have to be a squire. Then C would be a knight, and his sentence “A is a knave” would have to be true, but A would be a spy. Contradiction. Therefore, A can only be a knave. From this it follows that C is a knight and B is a spy. The unique assignment is: A = squire, B = spy, C = knight.