When we talk about writing, one of the most basic dichotomies is “fiction” and “nonfiction.” We tend to think of “fiction” as things that somebody made up, and “nonfiction” as things that happened and are being reported on.

Except that it’s just not that easy.

Let’s say that you go to a sporting event in a big, crowded stadium. The game is over, and as you’re going to your car, two guys in front of you get into a fight. There is scuffling, punching, blood flies. After a few moments, the two men separate and go to their own cars, each throwing hostile glances over his shoulder at the other guy. What can you say about that? You can report the facts (and by “facts,” in this case, I mean “scenario I made up out of whole cloth”). The problem is that each of those guys will come to you and say “That’s not what happened,” and will then explain to you that the other guy spent the entire game winding him up, insulting his team, insulting his wife, his mother, his choice of beers and then, as they were leaving, the other guy started it.

Do you put that into your story? If you choose not to, can you still call your story “nonfiction,” since you’ve chosen to leave out pertinent facts? If you find out that one guy has a long record of convictions for assault and the other guy recently went off his lithium, do you put that in? How about if one participant was Chinese and the other Argentinian? Or that one was 75 years old and the other on crutches? Do you even know if that had any bearing?

The point is that even newspaper reporting, the gold standard of “just the facts” writing, is skewed toward a certain point of view. The reporter chooses from the available, verifiable facts only those that seem most pertinent to the story and leaves the rest out, no matter how much the rest might mean to something like a criminal investigation or a civil lawsuit.

But where nonfiction is concerned with taking all of the available details about a situation and picking and choosing among them to craft a certain kind of story, fiction writers have exactly the opposite job. They start from the story and pick and choose what details to add to support it. This is where verisimilitude becomes critical. Verisimilitude means that a literary work depicts something real, something believable. To Kill a Mockingbird has verisimilitude. The Story of Babar does not.

Verisimilitude is different than the truth, because, to quote the old adage, “truth is stranger than fiction because fiction has to make sense.” So if you depict Leonardo da Vinci leading a robot army, no one will believe you, despite drawings he made of both armored tanks AND robotic knights. If you portray American cowboys calling police “pigs,” no one will believe you despite the fact that the use of the word “pig” to describe police dates back to the 19th century.

If, as fiction writers, we want to talk about something that actually happened, but “fictionalize” it, that is to say make it seem like something that happened in a different place at a different time to different people so that we don’t get sued or socially shunned or beat up, we have to double back on the whole “make the scene up from scratch” scenario. We have to take a real event, take out telling details of one kind (and we decide what kind that is), and leave in details of some other kind. But then we have to replace the stuff we took out with stuff that we make up, and we have to make sure that the stuff we put back in keeps the story the same. That’s where it gets so, so tricky.

I want to talk about my best friend who skinned her knee roller skating when we were 9, but do I leave in the roller skates or the fact that we’d ditched school to do it and she couldn’t go back to school with a bloody knee, or that her dad beat her for ditching school and never let her come to my house again? (And no, that never happened either.) What do I take out and what do I leave in to create the same story of risk and error and loss without putting either myself or my former friend at risk?

These are the really hard choices we make as writers, and every time I find myself in this situation, I always have to ask myself “why does this matter”? If what matters is that I feel I was unfairly scapegoated as a child, then I can tell that story any number of ways. If what matters is that my friend’s father was an abuser whose only punishment for any infraction was a beating, that’s a different problem to solve.

At the end of the day, it’s down to the individual writer to decide what they’re writing. How much do you want to massage the facts of an event you witnessed and are presenting as the truth? How much do you want to stick to believability when you talk about a fictional meeting between two famous people? How much do you want to protect the people you know in real life when you’re putting them into a story that may or may not have ever happened?