hawkeyefan
Legend
Now it's possible to have a prepared scenario in which player choice matters to the generation and delivery of theme. Off the top of my head I can't think of any published D&D module that is an example, but there are numerous examples in the Prince Valiant rulebook and the Prince Valiant Episode Book. Another example is found in the HeroWars Narrator's Book by Robin Laws: The Demon of the Red Grove. But I don't think those scenarios are what @hawkeyefan had in mind - he was clearly referring to D&D modules. And frankly I'd be surprised if you have these examples in mind either.
I'm trying to think of any D&D modules that work this way, and I don't think there are any. There are so many that it's possible I'm unaware of them... but I wouldn't be surprised if there are not. They're intentionally designed not to work that way.
Now, module play is not the end all be all of D&D. Folks can play their home game however they choose. But I think an important factor here is that module type play is the most well-known and observable play style, and it very clearly does not address the themes and concepts of specific characters. This is important because this style of play allows for this... it does not require addressing the themes of the characters in the same way that a game like Masks does. Looking at @Campbell 's example with his Protege character. If the game doesn't address the relationship between the mentor and the protege and the details that have been established about them, and how that impacts the Protege's relationship with his team... then the game has failed to do what it's supposed to do.