When Malfoy had gone, Ron and Harry looked at each other. “What is a wizard’s duel?” said Harry. “And what do you mean, you’re my second?”
“Well, a second’s there to take over if you die,” said Ron casually, getting started at last on his cold pie. Catching the look on Harry’s face, he added quickly, “But people only die in proper duels, you know, with real wizards. The most you and Malfoy’ll be able to do is send sparks at each other. Neither of you knows enough magic to do any real damage. I bet he expected you to refuse, anyway.”