I've been thinking about the hero in my current work in progress today. The challenge in writing a hero is making him appealing to all women who read the story. If we can get the reader to fall in love with our hero, at least for the duration of the story, then we've done our job. And since romance novels are mostly written by women for women, it's all about the hero.
That doesn't mean the heroine is completely without purpose. She must be someone the reader can identify with on some level, have goals and motivations the reader can get behind and want her to succeed. She must have strength of character and be worthy of the hero's love. But, let's face it, do we really care if the heroine in a romance novel is dripping with sex appeal?
Which leads me back to the hero. What makes a hero universally appealing? It's got to be more than looks. Though that sex appeal I mentioned doesn't hurt a thing. He must have some noble and worthwhile attributes that go more than skin deep. Even when he's acting like the bad boy, there are certain lines of behavior he won't cross. And speaking of bad boy heroes, they're my favorites and the most fun to write.