Guns-on-the-Wall
If a writer tailors their writing toward a reader, rather than writing something intended to be purely private, they need to keep the reader’s expectations in mind. In a sense, there is an agreement that the writer enters into with the reader; an agreement that the writer will give the reader what they need in order to make sense of the story. To this end, the writer uses all their tools; characterization, setting, action, worldbuilding, and all the others that the writer carries around in their virtual toolkit. Many plot elements are fair game in order to keep the suspense going while still maintaining that agreement; red herrings, misdirection, and confusion in the minds of the main characters, for instance.
But there are a few things that break that implicit agreement, and one of the major ones is giving the reader false information in order to create artificial suspense. You can give the characters false information – that’s fair game – but if you give the readers false information, you’re not setting up the story in a way that makes real sense. And one form of this is to have a gun –on-the-wall.
This principle, also known as “Chekov’s Gun”, is this:
Remove everything that has no relevance to the story. If you say in the first chapter that there is a rifle hanging on the wall, in the second or third chapter it absolutely must go off. If it's not going to be fired, it shouldn't be hanging there. — Anton Chekhov
Since this is a clearly significant detail, the act of putting it out there in the first place means that it needs to have significance in the story. In other words, you’re presenting something to your reader that you are implying will make a difference later on. If it’s not, you’re making a promise to the reader that you don’t intend to keep. In a way, you are cheating the reader by simply trying to fool them directly rather than use the tools in your kit. You may not intend to be doing that, but in effect it’s what the reader takes away.
Of course, what’s necessary to the story may vary in the eyes of both writer and of reader. If one is doing extensive worldbuilding, one may have a lot of details which, though they don’t directly relate to the specifics of the plot, enable a broader understanding of the context in which the plot happens. Using descriptions to firmly anchor the setting is also something quite reasonable to do as an author. If you are a writer who likes detail, you’re bound to be putting in a lot of detail that isn’t strictly necessary to the plot. It’s not really difficult to do this by accident; breaking the agreement with the reader doesn’t have to be deliberate.
So how do you know if it’s reasonable detail that doesn’t need to be followed up on, or whether you’ve got a good, old-fashioned gun-on-the-wall? Especially when it can be accidental on the writer’s part?
I suspect some of the time you don’t, because of that level of difference between tastes. But a general rule of thumb might be to consider whether the reader has a reasonable expectation that the detail in question should be there and whether it’s a reasonable part of the worldbuilding, or whether it is sufficiently noticeable or out of place that it’s going to especially flag the reader’s interest. If one is building a military society, and a character is a military man, and his medals and weapons hang all over his office wall, that says something different than if a character is a pacifist, and makes a point of saying, “My grandfather owned that gun, but I would never dream of using it.” The first shows a context where the gun doesn’t stand out, the second is doing everything but painting stars and arrows next to the gun.
This can also happen to ordinary details that are perfectly normal in context, but that the author simply emphasizes a bit too much. For example, if a character always looks around the military man’s office and notices the different guns hanging there every time, you are beginning to tell the reader that these guns are significant, not simply scene-setting or worldbuilding. And it’s that significance that the writer needs to be aware of as they are creating their scenes.
Like most elements in your story, paying attention is the key, as well as trying to see it through your work through a reader’s eyes. Watch for those guns, and either take them down from the wall and put them into the gun case, or make sure they go off!