OK I asked this question but didn't get the answer I asked?

In novels, particularly like best sellers and such but really any fiction novel, if you take any sentence from the book would there be absolutely no grammatical errors in it at all?? I just got done taking the ACT and it seems like style, organization, misplaced modifiers, redundancy, wording, unclear-ness are so easy to fall into that I was thinking do novels really have to follow these rules?? Can they be as wordy, confusing,grammatically wrong as they want (in moderation)?? Because with so much writing they eventually must make a mistake somewhere.