Henry James is credited with saying, “Character is plot.” I can see truth in this statement, because characters are integral to plots, the actions of the stories. What a character does - his thoughts and reactions, and the results of his actions – this comprises the plot of the story. Plots shouldn’t be unbelievable; the actions of characters should make sense based on who the characters are or are becoming.
If character is plot, dull characters make for dull plots. If readers don’t care about a main character, aren’t interested in what happens to the character or what events are caused by the character, why would they keep reading?
Plot is what drives the story, what keeps the reader turning pages, and sometimes readers can keep reading if the plot is fast-paced, even if the characters aren’t interesting. Personally, I’m typically not drawn to character-driven novels with little action. Sometimes these novels interest me when I’m interested in the characters, but I have to be in the right mood with the right character-based novel to fit that mood! And, if I don’t find myself caring about the character, or if I find myself losing interest in the character, I put down the novel and move on. On the other hand, novels with quick pacing can have, to a certain extent, two-dimensional characters, and I’ll keep reading.
A good tip I heard from one of my professors from my time spent in writing school: if you, the writer, gets bored reading your manuscript, you can be sure the reader will become bored, also.