To take a very obvious example: if I write a story about a young girl who finds an injured puppy and takes it home and nurses it back to health, to then have that puppy die in a fiery car crash would in most cases be betraying the reader–the contract, set up at the start, was that the injured creature would be healed, and I’d be breaking it at my peril. This isn’t merely a matter of that story being for young readers. I could, conceivably, have decided from the outset that I wanted to write a story about loss for young readers, in which the puppy was indeed going to die: but the setup would be different. There would be cues from the start that this was the sort of story in which something sad might happen. The balance and tone of sadness when the injured puppy is first found would probably be different, too; the focus would be shifted. I wouldn’t be killing the puppy simply because it’s an available bit of emotional angst; I’d be killing it as part of a larger picture in which it made sense. If I didn’t do all these things; if I simply killed the puppy in a final twist without them; I would be breaking the contract. But the signs, especially as stories get older, are much more subtle. In one of msagara‘s books, there’s a character who’s very much set up to be the sort of character who survives, and yet said character doesn’t, and yet on reflection the book never promised he/she would. (There–how’s that for not giving a spoiler?) (Though actually, since I’m still finishing the Sun Sword books, this may happen more than once, too.) To my reading, the death went against expectations, but not against the contract–and because of these was wrenching but not emotionally manipulative. Thinking about it, Diana Wynne Jones’ books strike me as good examples of stories that don’t often make promises to the reader. Ditto Garth Nix’s Sabriel/Lirael/Abhorsen. Yet making promises–setting a contract–isn’t a bad thing, or something only second-tier writing does. Many of my favorite stories make promises. Harimad-sol will not be crushed by any mountains, though she may be humbled by them; Charles Wallace will never decide he just wants to stop fighting darkness and be a normal boy. Meg Murray’s deciding she just wants to settle down and raise children, however, does border on a breaking of contract. Come to think of it, so does Tenar settling down to live an ordinary life–which would explain why, while I love _Tehanu_ now, I loathed it when I first read it–it was written later, when Le Guin was no longer working under–no longer believed in–the same assumptions and promises she’d made some decades before.
So where does the contract come from? I can look at a book and say, “The writer has promised these things to the reader”–but I can’t always say why. It’s not that the orphaned, lonely, heroic young wizard has to survive–it’s that in certain stories the orphaned, lonely, heroic young wizard has to survive. In other, outwardly similar stories, he doesn’t.
In stories that have made a contract, the breaking of it often amounts to cheap emotional manipulation. Yet in stories that haven’t made promises, the same actions–especially if they are playing against known types–are extremely powerful.