Phobias are overwhelming and irrational fears that plague a hero’s psyche.
Whenever a character is in the presence of his phobia (GM’s call, but generally sight), he subtracts 1 from all his Trait rolls if it’s a Minor Hindrance, and 2 if it’s Major.
Phobias shouldn’t be too obvious; everyone should be afraid of vampires, for example, so it’s not a phobia, it’s common sense. Instead, the phobia usually centers on some random element the mind associates with the event. Remember, phobias are irrational fears.