That is, until you realize that the word count is stacking up and your characters have been talking for pages and pages with no end in sight, and everything is turning into that Council of Elrond scene from The Fellowship of the Ring. Not the film version. The book version. You know, the scene when all the characters sit down for a big meeting and spend approximately four hundred years discussing the history of the ring, why it needs to be destroyed, the whereabouts of Gollum, what they had for breakfast, etc. It is important information, mostly, because we learn why the ring is so dangerous and just how high the stakes are, but I don’t think anyone other than the most hardened of Tolkien fans ever actually reads all that stuff, because seriously, it goes on. And on.
So, if you find yourself in a situation where you realize your exposition has overwhelmed your dialogue and your main character is on the brink of volunteering to take the One Ring to Mount Doom just to MAKE THIS GODDAMN SCENE END ALREADY HOLY CRAP, here are some questions to ask:
Is this information really necessary? Sometimes when you've built a world from scratch, it can be hard to see which details are interesting and necessary and which are, well, not. What would happen if this information was left unexplained? Would it leave your readers with a deeply lessened understanding of what your story is about and why everything happens the way it does? Or would it make no difference? Maybe it doesn't need to be explained in this stretch of dialogue, because it's something a reader can pick up on gradually from the context of everything around it without having the information laid out, or maybe it would fit even better in a different conversation. Or maybe it doesn't need to go in this dialogue because really, it doesn't need to go anywhere. After all, not every detail of your world building has to make it onto the page*. Think of the each thing you leave out as an extra layer in your world's atmosphere, a layer which makes the story and its universe richer and more real, even if you're the only one who knows about it.
Is this dialogue organic to the characters and the story? Does it make sense that these characters would be having this conversation, in this place, at this point, in this much detail? Are people explaining things to each other that should, in fact, be totally obvious to anyone who lives in their world? Are they still speaking as people, each with their own motivations, conflicts, contradictions, secrets, and emotions? Or have they turned into cardboard cutouts who exist solely with the express purpose of Explaining All The Things?
Can this information go somewhere else and/or be communicated more effectively by other means? Maybe that exposition might work better if it's not shoehorned into a conversation where it doesn't fit. The film version of Fellowship of the Ring moves a whole heap of the most important information from the Council of Elrond scene to the prologue sequence and other parts of the film, allowing the council scene to be stripped down to its most important conflicts without confusion. (Or boredom.) Sometimes it's worth experimenting with different ways of communicating the exposition too. Would it be better as straight up description? After all, 'Show, Don’t Tell' is a guideline, not a rule. In Steering the Craft, Ursula Le Guin says, “There's a tendency to fear descriptive “passages”, as if they were unnecessary ornaments that inevitably slow the “action”... [A] landscape and a great deal of information about people and a way of life can be the action, the onward movement of the story...”
What is truly happening here? Does it amount to more than just “people talking to each other”? Because it should. Even if there is little in the way of overt action, there should still be things going on under the surface, and a sense that your scene is building towards something. Are there tensions between the characters and forces beyond them? Tensions between the characters? Tensions within the characters? What are characters saying? What are they not saying? And what would they never dare to say, even to themselves? These things will make your dialogue compelling, and your exposition compelling with it, whether the tensions are overt and explosive, or underground and rumbling like an emotional fault line beneath your characters’ feet.
How do you make exposition and dialogue work together?
*Unless you’re really into writing Tolkien-esque appendices, I guess.