A couple of years ago, we (that is: Ladylark and me, hello, @kayanem) had a conversation inspired by a twitter thread, now deleted, and came up with words to describe a concept that we’d both noticed but not properly put into words before. That is, the idea of ‘concretes’. We’ve found ourselves explaining it a few times recently in conversation with others, because it’s ever such a useful concept, and now we’ve seen some of those people start telling others about it. This is great! Please carry on, so we can use it the way we do between ourselves as a quick shorthand, and not have to explain it every time.
So, for posterity, here is what it means:
The original inspiration thread spoke about different adaptations of Shakespeare’s plays. When performing any given play, you might want to keep it fairly close to the original - though since there are limited stage directions, there’s always going to be some interpretation. Or instead, you might take more liberties, choosing scenes to keep or drop, merging or shifting characters. There are many different interpretations and changes you can make, and these can go in all sorts of directions. But you can't change everything all at once - there’s a limit you hit when it's no longer really the same play. All adaptations fall on a spectrum from closely faithful to loosely based; compare the BBC adaptation of Pride & Prejudice to Bride & Prejudice, to the Lizzie Bennett Diaries, to Pride & Prejudice & Zombies… They’re all adapted from the same source material, but how recognisable they are as ‘Pride & Prejudice’ is variable.
In any adaptation or transformative work (including fanfic) there are aspects that remain fixed, to make it a recognisable part of the continuum with the original. In fanfic, people often concentrate on retaining either the setting, or the characters. In the case of characters, there are certain aspects at the heart of what makes a character 'them', that have to be retained to make them recognisable across fic, whether AU or canon.
It’s generally the case that the author will choose some of these specific aspects of the character that persist across interpretations. These are the ‘concretes’, the essential structural essence, that make a character recognisable as that same person. Any character is made up of a whole range of these, and which ones people choose to focus on can vary. Further, these concretes can come from canon or fanon, and so also give you an insight into the community that has shaped that person's understanding and writing. So for example, an author writing Star Trek fic might consider ‘being half human half vulcan’ to be a fundamental concrete of the character of Spock. Or being driven by logic and controlling his emotions. Or being part of the starship crew. Or being in love with Kirk. Or all of these, or none of them, but other aspects that retain him as a recognisable character. Concretes are rarely physical traits, although depending on the character and how that character feels about their physical form, it could be!
Concretes are often character traits which are ‘non-negotiable’ to the author in representing who they are writing about. But sometimes an author might choose to intentionally discard a concrete and highlight that, to see what it does to other aspects of the character. That can become a balancing act; if you remove a part of the structural concrete, the rest has to be strong, otherwise it just turns into original fiction.
Looking at what character concretes an author chooses to retain in their fic is fascinating, for what it tells you about the writer, and their mental construction of the character, as much as storycraft. So, for example, in fic of Our Flag Means Death, is a concrete of Stede that he leaves his wife? Or that he likes flamboyant clothes? Is a concrete of Ed that he fancies a fine fabric? Or that he has an injured knee? Or that he is Maori? The choice to include or not include any of these is not right or wrong, but an insight into how the author mentally constructs and fills the box of character traits that makes up ‘Stede’ and ‘Ed’. If none of these are in that box, what else is there that connects this version of Ed or Stede with that we see on screen, or that might be in the reader’s mental box?
This highlights a final important point - that the other side of concretes is from the reader’s point of view. Readers sometimes complain that a fic is ‘out of character’. What they might actually mean is that the concretes that the author has considered fundamental to the character are not the same as those in the reader’s construction of what is vital to that character. Or it could mean that an author really has removed too many concretes, and the essential structure of the character has been too fundamentally changed. Everyone’s concretes, and everyone’s tolerance for them being shifted, are going to be different.
Concretes are just a really, really useful way to refer to the character’s essential defining components, and which of these elements it is possible or desirable to retain, change or remove across adaptation and transformation.