There's a movie, very popular among Fantasy folks, called The Princess Bride.
The story doesn't matter (hero rescuing a princess... big fights.. Andre the Giant.. so on), the following scene does.
The hero, at one point, met with one of the villans who thought of himself as extremely smart. As such, the hero challenged him to a match.
Two wine glasses were placed, one in front of the hero, one in front of the villan. Both filled with the same wine. The hero tells the villan that one of the wines is poisoned by the hero. The villan's job is to choose one of the wines to drink (with the hero drinking the other wine). Whoever lives, wins.
The villain then went thusly:
All I have to do is divine from what I know of you: are you the sort of man who would put the poison into his own goblet or his enemy's?
Now, a clever man would put the poison into his own goblet, because he would know that only a great fool would reach for what he was given. I am not a great fool, so I can clearly not choose the wine in front of you.
But you must have known I was not a great fool, you would have counted on it, so I can clearly not choose the wine in front of me.
Because iocane comes from Australia, as everyone knows, and Australia is entirely peopled with criminals, and criminals are used to having people not trust them, as you are not trusted by me, so I can clearly not choose the wine in front of you.
And you must have suspected I would have known the powder's origin, so I can clearly not choose the wine in front of me.
..and so on.
The problem is that the villain is trying to guess what the hero is doing. Every time he thought of a reasoning that the hero would use, "That's what you WANT me to think!" would show up and it would make sense for the hero to reverse it. The villain is now stuck and unable to choose.
This, in mafia, is called Wine In Front Of Me, or WIFOM. Whenever a person acts in a way that causes you to have to guess their intentions you risk getting stuck in the same reasoning:
Person 1"Dakarian says that the mafia typically are lurkers and that he is active so he's town"
Person 2"But that's what he WANTS us to think.. oh no, Dakarian is scum trying to look like town"
Person 3"But that's what he WANTS us to think..Dakarian is town"
But...
WIFOM is one of the most powerful weapons the scum have, more powerful than the Nightkill. A town full of WIFOM is a truly dead town. Note that it's VERY easy for both town and scum to start WIFOM. However, whether it's from town or scum, it's never safe for the town to delve into it. The town needs to use logical reasoning that comes to firm conclusions and investigations to find more information that will lead to the needed reasoning.
Whenever you find yourself able to fit in "That's what they want me to think" into your reasoning without messing things up then you are drinking WIFOM... stop NOW.
Btw, the answer to the Hero's puzzle? Both wines were poisoned. The hero was immune.