What are their characteristics? Where is the line between the attractive traits of being a bad boy and just being a prick?

I've seen my fair share of pricks acting like pricks but for some reason the opposite sex see them as a a bad boy, so I'm just trying to get a better gauge on where the line is.

If there's one thing that it all keeps coming back to it's something along the line of: bad boys don't care. They do what they want regardless of the outcome. And there's truth to that but I find that to be a gross oversimplification. But hey, maybe I'm wrong. Maybe that's the secret sauce.