The bad boys.

I know. I know.

He shows up in a lot of novels. You know who I'm talking about. It is that dark brooding bad boy that we all love. We love the guy who can't be tamed and whose rough exterior hides passion and allure. The heroine may hate the man or want to fix the dude, but no matter what by the end of the story she is with him.

You might want to roll your eyes at this theme, but it is as old as time. There are many instances of this trope in classic literature, and it became particularly prominent in the 1800s. A famous example is Heathcliff from Wuthering Heights or Mr. Rochester from Jane Eyre (I read that when I was sixteen.) 
Anyway, the point is, this guy is here to stay, and he offers a particular challenge for authors. You see the character must be bad to bring that danger and tension to the story, but he can't be so bad that he turns into the bad guy. Also, there is a slim line that must be walked so that we don't hate the character by the end of the novel. I have had that happen to me before.

As I write I keep in mind the characters overall morality and likeability. This is complex. I have to have him honorable in some ways but ruthless in others. I want him cold yet with his love match, he has fire. I need that compassion in some places, but we all love a rule breaker, don't we?
I tend to like outsiders because I feel that way in my own life. So often my bad boys are not family oriented, but I want them to yearn for connection.

I am working on a character like this right now. He is a handful, but I'm getting there. I can't wait for you to meet him in 5:05 a.m.