Not every story needs four-dozen parts. Some, but not all. Some stories, including some multi-part series, in fact, would have benefitted from being much, much smaller.
Stand-alone stories in fantasy and science fiction or whatever you want to call the genre should be encouraged more, and honestly, I wish more people would buy them, thereby encouraging their proliferation. I suppose writers must listen to the marketplace to a degree, but I wonder if the apparent dearth of stand-alone stories is not so much a reaction to the marketplace, but the marketplace reacting to what the publishing industry has been feeding it for so long.
It’s like television or popular music: we lament how everything looks, sounds, and feels the same, and yet people keep buying it. My theory is cynical, but I think it explains a lot of what we call capitalism: if one thing makes tons of money, every single other firm in a given business sector moves as one uncoordinated school of fish to do the exact same thing until there’s no more money left in it before moving on to the next trend.
Who can we pin the blame on? J.R.R. Tolkien? It sure seems that the generations who grew up reading The Lord of the Rings and fell in love with fantasy and writing as a result all wanted to make their own trilogies. But there were plenty multi-part stores pre-Tolkien, whether or not they were one coherent narrative or various stories set in the same—and may God forgive me for uttering this term—universe. Off the top of my head, H. Beam Piper comes to mind.
Marketplace stuff aside, this topic was spurred by my friend, author Jon Del Arroz, mentioning that he wished there were more stand-alone stories being produced, and then a follow-up question asking your humble writer how to avoid story bloat.
I do not pretend to be an expert, but as one who has published one stand-alone story, is working on another one, and has about five unpublished stand-alone stories just waiting for a polish, I do have some experience. And all of my advice boils down to one word:
That’s it. That’s the big tip. If the theme of your story can be conveyed in one book, whether it be 1,000 pages long or 200, then that should be sufficient. If the story calls for more, then give it more.
Like most things, however, the concept is simple while the execution can be tricker.
The call for restraint is why I am an advocate of having at least some form of outline or structure planned before you start writing, or at the very least knowing or having a relatively clear idea of how your story with end. There can be fun and exciting plot beats along the way. There can be sweeping epics or romances chock full of heroism, villainy, and world-shattering events. But even these benefit from a sense of knowing when to pull back.
Switching mediums, think about common criticism of progressive rock—too many solos! Did the keyboard player really need to take another turn at minute 23? And the songs are too long! It should have ended at Part VII; why did they add parts VIII-XXIII?
Your writing could benefit from a similar sense of scale. If you have a story that comes to a satisfying conclusion in one book—or maybe two!—leave it at that. It requires a lot of self-discipline, but if you have the self-discipline to write multiple books in the first place, you can write a stand-alone story—and stand-alone stories have an added benefit of potentially helping you, the writer, avoid the creative burnout of working on the same project for years on end. At the very least, a stand-alone story will require far less planning.
And who knows? Maybe by offering an alternative to the glut of lengthy series filled with Bible-length books you will attract an audience eager for something different.