Writer's Fallout Shelter

A symbol can be used for almost anything. It's simply something that stands for something else, and can be nearly anything. Symbolism can be as simple as the king in Hamlet using the "we" pronoun instead of "I" in order to symbolize his soveriegnty, which didn't play into the themes of the story. (Or maybe they do. That's the tricky thing about themes; it often depends on your point of view.) Just a short while ago there was a thread dealing with how actions can symbolize moods and such. Not to say that symbolism can't play into the theme; it does a lot of the time. They just don't absolutely have to relate to each other.