Explain more about the rules for declaring sheriff.
A player is declared as Sheriff as soon as he says
I am the Sheriff now.
(Variations are fine too, like "I'm the new sheriff in town!" or "Obey me citizens, I am the Sheriff now". The point is to make it clear you are taking the role, while allowing some role-play.
A bad example is saying "There's a new Sheriff in town", because it is not clear if you take the role or not.)
Explain what neighboring survivors means.
Neighboring players are next to each other on the signup list. The first and last players also neighbor each other.
And a special rule: Ghosts do not count when checking who are neighbors.
