"is the room filling with water?"
me,I =prisoner
guard1=truthteller
guard2=liar
I would ask guard1 " if I ask the other guard what door do I go through to freedom what would he say?"
guard1 replies: " he would say my door"
((this means that the door to freedom is behind the liar since he is lying))
then I would ask guard two the same question " if I ask the other guard what door do I go through to freedom what would he say?"
guard2 replies: "he would say his door"
((he would say that because he cannot tell the truth))
(( guard1 has already identified that the freedom door is behind the liar))
(( so if I asked guard1 directly which is the door, he would say the one behind the guard2(liar))
(( guard2 could never tell u "he would say the door is behind me" because that would be the truth. Therefore he must lie and say the door is behind the truthteller.))
So now you know what door to go through.
For the skeptics
If it was reversed and guard1 was a liar and answered the the question the same. " he would say my door"
(( this would mean that the other is honest meaning that guard2 would actually say " the door is behind me"
Now when you ask guard2 the same question, being that he knows that the other guard will lie, he also cant lie about what the other guard's reply will be; and he knows that the door is behind him.))
Therefore his reply would be: " he would say the door to freedom is behind him(guard1)"
So you know that the door is behind guard2
