I wanted to elaborate a lot on my answer to #10 in the article mentioned in this post, because it deserves a longer, more sensible answer than sass and a head flip.
'No unsympathetic characters.'
I strongly agree that this is a rule that should be broken more, by writers who know when, where and why to break it.
I've seen a lot of advice to new and/or young writers, the gist of which is: 'make even your villains sympathetic because if there is no sympathy point, then readers can't identify with them.'
I disagree. Partly.
First of all, it is a general rule and should definitely be broken sometimes just because every story is different and unique and as you listen to each story in your head and learn its voice, sometimes it demands this kind of character.
More and more lately I've seen books that follow this general rule becoming
shades of gray. (*gasp* Yes, I said it and yes, I hate that book
for forever ruining a perfectly good and very useful phrase.) I've
seen it take writers to a place where there is no black or white. When
everyone is sympathetic and
even the villains are all excused, where is the line between what's
wrong and what's right?
I personally believe that in order to identify with a character, a reader does not necessarily have to sympathize with them, but they do have to understand them over the course of the story. I don't think that you have to make a character sympathetic in order to understand them. (I also think that you can make a villain sympathetic without excusing them, but that's somewhat off-topic for today.)
Characters in a book or movie should be true to life, no matter how unrealistic or fantastical the setting is. Humans stay the same, in all time periods, in all circumstances. There is nothing new under the sun and humans will always be human with human reactions and emotions. (If someone is writing about robots or aliens, obviously, this doesn't apply to them in the same way.)
Case in point: a character who wants power just for the sake of power.
There is nothing sympathetic in that. Let's say he had no traumatic
childhood, no reason to want power for revenge or payback, no one to
protect with it or help with it. He just wants power. People like this
really do exist.
Let's look at Hitler. He may have had a rough younger years, he
may have been lonely and what-have-you, and his national spirit may have been smarting under the blows and sanctions dealt Germany after WWI but guess what? Most of his
actions before and during WWII just can't be sympathized with or excused. They were actions of arrogance and prejudice... and thus very human. And although Hitler is an extreme
example, every single day people do bad things from similar motivations; thereby leaving no way in which they can be excused or even evoke sympathy.
In fiction, we need realistic, three-dimensional human beings and sometimes this means just plain hate-able people.
In the end, every single story is different and the key is just to listen to its unique voice in your head; whether this means villains who twist your heart because they've had tragic pasts and they let it turn them into what they are now... or whether it means someone who is just an absolute jerk for the simple reason that they can be and therefore have decided to be one.
Happy writing and may all your characters be realistic and understandable.