Masello's seventeenth rule is another rather simple one. The idea behind "Make 'Em Worry" is that stories need conflict and obstacles to be interesting. There's no point in writing a story in which your main character wants something and then in short order gets it. What makes a story work is that your characters want something and have to fight for it.
But as writers, we sometimes have a problem with this rule for one very simple reason. We like our characters too much. If we didn't like them, we wouldn't want to write about them. And because we like them so much, it can hurt us to put them through their paces. But we have to do so, or else there's no story. Or at least no story worth reading.
I remember the difficulty I had with this when I wrote my first published story, "TeleAbsence" (Analog, July 1995; reprinted in Wondrous Beginnings edited by shsilver). For those of you who haven't read it, the story is about a poor boy named Tony Louis, who desires a good education and sneaks into a virtual reality school to get it. The first draft was half the length of the final story, because I introduced the problem he had and let it get solved too quickly. In the second draft, it took him longer to solve the problem, but the solution was a little too perfect. Once again, I have to thank Stanley Schmidt, editor of Analog, for making me rework the story again and again until I finally got it right. In its final version, the obstacles are there and Tony has a lot more difficulty overcoming them than he did in the first draft.
We should emulate writers like David Gerrold, who discusses in his own book on writing how he sometimes does an exercise where he writes an interview between himself and his main character. He once "interviewed" Jim McCarthy, the protagonist of his "The War Against the Chtorr" series. McCarthy (and the whole human race) goes through an ongoing devastating invasion during that series, an invasion that begins with the death of 80% of the human race. Gerrold says that when he introduced himself to McCarthy as the author of the series, McCarthy came at him with a knife and he barely managed to escape with his life. That's how our characters ought to react if they ever meet us; we should make our characters suffer, so their victories at the end are that much sweeter.