These books, written by a British author, are full of characters with strong wants who are roused into situation-defying action.
These books are also best-sellers on _both_ sides of the pond, and often share shelves with Adams.
That's one of the main reasons that Terry's work comprehensively bridges the genre gap between "children's books" and "modern philosophy".
1) Starting the story by Resisting the Call to adventure -- in a way that reveals strong character motivation (a strong desire to live)
2) He suffers a series of trials that slowly push him to the opposite view: That he must act boldly and selflessly if he is to survive (and thereby also save the Discworld)
3) He performs a heroic act (even if only armed with a "half-brick in a sock") contributing to the good side's overall victory
Although to be fair, he does tend to revert by the start of his next story.
I'd say that's most of the Discworld series though. Protagonist is living peaceful, MacGuffin ensues chaos, Protagonist (or Arbitrary Thing) saves the day, the Disc goes back to normal, and the Turtle continues to move.
Discworld is my favorite series and I think Hogfather and Feets of Clay should be mandatory reads for people going into AI.
Does he, though? I don’t think he acts heroically even once. Though I would not be surprise if Pratchett actually defies expectations and made him a genuine hero once or twice; it’s been a while since I read the Discworld books. Rather, acts that look heroic from the outside if you squint happen to him despite his best, incompetent efforts to stay out of it.
4) Confusing pretty young women with potatoes.