In another forum, there was some discussion along the lines of, "What's the biggest problem you have as a writer?" I chimed in, and the answer I came up with seemed worth sharing:
The single biggest thing I have a problem with is the WDTJSH, or Why Don’t They Just Shoot Him problem.
WDTJSH is one of those things where you find yourself inventing increasingly contrived explanations for why things have to work out a certain way, usually to force the hand of the plot or the characters towards some predetermined conclusion. I chose this name for it because it usually reveals itself when you’re re-reading what you’ve written and you throw the manuscript down in exasperation and shout, "Why don’t they just shoot him!?"
Whenever I’ve found myself in a WDTJSH cul-de-sac, I try to back out of it by asking myself this:
What is the destination I’m trying to strong-arm everyone involved towards?
What is the significance of that destination? Why do they have to end up there? What meaning does it have for the story?
Is there not another way to achieve the same meaning by way of the things we already have?
When you restate the problem in those terms, you discover very quickly how to back out of dead ends like this.
Another way I put it: If you run into a difficulty with a story, there’s a good chance that’s a sign the difficulty in question is the real story.
Example: In Flight of the Vajra, there is a far-future spiritual path, one constructed in such a way that I quickly realized it wouldn’t last more than a few generations without suffering a major schism. I quickly realized that was the story I needed to be telling, and soon many, many other parts of the book fell into place after it.
"The difficulty is the story" made that book what it is now, and I would deign to argue the other two since then as well. I can't vouch for the others before it being the same way, but I'm just grateful I stumbled across this principle at some point rather than never.