The characters are the plot. What they do and say and the things that happen to them are, in a sense, what the plot is. You can't take character and plot apart from each other, really.

WHAT WOULD HAVE HAPPENED IF YOU HADN'T SAVED HIM? "Yes! The sun would have risen just the same, yes?" NO "Oh, come on. You can't expect me to believe that. It's an astronomical fact." THE SUN WOULD NOT HAVE RISEN. ... "Really? Then what would have happened, pray?" A MERE BALL OF FLAMING GAS WOULD HAVE ILLUMINATED THE WORLD.

And that's when I first learned about evil. It is built in to the very nature of the universe. Every world spins in pain. If there is any kind of supreme being, I told myself, it is up to all of us to become his moral superior.

You have the effrontery to be squeamish, it thought at him. But we were dragons. We were supposed to be cruel, cunning, heartless and terrible. But this much I can tell you, you ape – the great face pressed even closer, so that Wonse was staring into the pitiless depths of his eyes – we never burned and tortured and ripped one another apart and called it morality.

Plot exposition that can be gently wound out by the authorial voice and internal monologue of a character in the length of a page has to be delivered in a matter of seconds on the stage.

It was Carrot who'd suggested to the Patrician that hardened criminals should be given the chance to 'serve the community' by redecorating the homes of the elderly, lending a new terror to old age and, given Ankh-Morpork's crime rate, leading to at least one old lady having her front room wallpapered so many times in six months that now she could only get in sideways.

The world is a globe — the farther you sail, the closer to home you are.