I'm not cruel, sir, I won't shoot you in the guts, but I will make you realize how much you took your toes for granted.

Never trust a species that grins all the time. It’s up to something.

Money is an unavoidable consequence, but it isn't the reason I write; if it was, I wouldn't have written any of the YA books, because advances in that field are small compared to what I'd got now for an 'adult' DW.

It cannot be said often enough that science fiction as a genre is incredibly educational - and I'm speaking the written science fiction, not 'Star Trek.' Science fiction writers tend to fill their books if they're clever with little bits of interesting stuff and real stuff.

It's never a good idea to ask a man on a tight-rope how he keeps his balance: a) he would probably fall off and b) he probably doesn't know what the muscles are called in any case.

Fresh wounds," said Angua. "But one of them did shoot one of the other in the leg by accident." "I think you'd better put in your report as -self inflicted- wounds while resisting arrest," said Vimes.

Aliens don't get stuck in air ducts. It's practically a well-known fact.