ElonnaT
How much can you change about what is already "known"? What I mean by this is that writers such as Tolkien, et al, have pretty much defined how people perceive fantasy concepts. For example, what elves look like, how magic works, whether a species is relatively "good" or "evil".
How much of this can be played with before readers just don't believe it because they have preconceived ideas and expect them to be followed?
How much of this can be played with before readers just don't believe it because they have preconceived ideas and expect them to be followed?