Okay, so I realize that many smarter people than I already figured this out. This post is for people, like me, who are better-than-average at spelling, sentence construction and mechanics. People who, like me, are often told that they write very clean copy. People who, like me, have sometimes wondered why they would need an editor before self-publishing. Upon re-reading my novel that I have fully revised TWICE and was now revising for the third time, AND which has been through easily a half-dozen beta readers, I discovered, among other things:
That most of the regiments and noble houses had at least two different color schemes for their banners and uniforms.
My main villain’s formal regalia was elaborately and stunningly described, with some of the best prose I have ever written… three separate and completely different ways.
During the climax, A military unit ambushed and murdered another military unit that it had relieved over a week previously.
The succession of the kingdom was arranged such that my villain could and should have solved the problem with a cup of poisoned wine and an unfortunate accident about ten years ago.
My protagonist’s nasty younger brother reacted to something before he ever showed up.
My protagonist’s personal rifle had a plot-activated bayonet.
Now, I’ve never used a professional editor, but I had read this thing a half-dozen times, had beta readers do the same, and while they pointed out a number of problems, these skated right by them. So I know the results of NOT using one. And they are to be avoided.
Edited To Add: I would like to say (because I meant to, but not strongly enough) that I do not mean any of the above to cast aspersions on my wonderful beta readers. Firstly, there was a lot MORE wrong with the novel when they saw it, and they caught a BUNCH of errors and weak points. Secondly, it’s not really their job to catch everything. That’s why you HAVE an editor.