Before I get into this, I want to make it absolutely clear that when it comes to showing vs. telling, one isn’t necessarily better than the other. One story might rely very heavily on showing, while another on a style of telling, both to great effect.
The problem with and Beauty of Defining
A lot has been said about showing vs. telling, and regarding something so subjective and encompassing as fiction, not only isn’t there a hard-and-fast definition for it, but it’s in the very process of defining it that we both learn more about it and about ourselves as writers. In other words, how you define show vs. tell determines how you show and how you tell.
So, without providing you a nice little definition here (sorry), let’s try approaching the subject from a filmic perspective:
The Analogy to Movies
I’m sure many if not all of you have seen Peter Jackson’s The Fellowship of the Ring. The prologue of that movie is a four-ish-minute sequence wherein we see and hear the history of Sauron’s schemes and Isildur’s resistance and victory.
Let me reiterate: We see and we hear this history. In other words, the movie shows us as well as tells us.
If you have the time and feel like it, play that link twice: The first time, close your eyes, and the second time, remove your headphones. How does the story change? Which experience do you prefer? Is there any information you can get from one but not the other? Do you doubt anything the narrator says?
Application to Literature
When we apply this to literature, things can get a little foggy. Ultimately, yes, everything in a (non-picture-) book is technically telling, but it’s a spectrum, and the two ends of the spectrum are what we, as writers and readers, have implicitly agreed to label showing and telling.
But it goes a little like this: If we can picture what is happening, it’s showing. If we’re being told the meaning of what’s happening, it’s telling. When the King raises his sword and shouts, he’s showing us. When the narrator tells us that their victory is near, she’s telling us.
Dialogue and Narration
What characters say in dialogue isn’t necessarily showing or telling, but the dialogue itself, as a rule, if you like rules, is always showing. You can have a character on-screen saying something, and talking is an action, and so it is showing.
Things get even hazier when it comes to narration, especially if the narrator is an actual character. Take Stranger than Fiction (2006) for example. Emma Thompson’s character spends the first half of the movie narrating Will Ferrel’s character’s actions, or telling us what he is showing us, but when Ferrel’s character calls her up and they talk, we’ve moved from the realm of telling into the realm of showing.
Whether to show or to tell in your writing depends, as does everything, on your goals. What effect are you trying to produce? Do you want create a reliable or an unreliable narrator? Do you want your readers to enjoy a bit of adventure, or reevaluate what they believe about human nature, the art of storytelling, etc.?
Again, I’m sorry that I can’t provide any solid guidelines here. But part of being a writer means defining those guidelines for yourself, and then deciding whether you want to follow or disregard them. Great writing is about breaking the mold, as has been said, but you have to understand the mold before you know how best to break it, and these days it often comes down to having to make the mold yourself first.