Never build a dungeon you wouldn't be happy to spend the night in yourself. The world would be a happier place if more people remembered that.

Cats will amusingly tolerate humans only until someone comes up with a tin opener that can be operated with a paw.

Dwarfs were not a naturally religious species, but in a world where pit props could crack without warning and pockets of fire damp could suddenly explode they'd seen the need for gods as the sort of supernatural equivalent of a hard hat. Besides, when you hit your thumb with an eight-pound hammer it's nice to be able to blaspheme. It takes a very special and strong-minded kind of atheist to jump up and down with their hand clasped under their other armpit and shout, "Oh, random-fluctuations-in-the-space-time-continuum!" or "Aaargh, primitive-and-outmoded-concept on a crutch!

He helped the Librarian up. There was a red glow in the ape's eyes. It had tried to steal his books. This was probably the best proof any wizard could require that the trolleys were brainless.

Granny sighed. "You have learned something," she said, and thought it safe to insert a touch of sternness into her voice. "They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance.

… you were so worried about legal and illegal that you never stopped to think about whether it was right or wrong.

You can’t say ‘if this didn’t happen then that would have happened’ because you don’t know everything that might have happened. You might think something’d be good, but for all you know it could have turned out horrible. You can’t say ‘If only I’d…’ because you could be wishing for anything. The point is, you’ll never know. You’ve gone past. So there’s no use thinking about it.