"But this time I won't ask you to duel." The professor clarified, becoming serious. "I have something completely different planned for you, which will come in handy for your N.E.W.T.s You'll need to be astute in understanding the danger that lurks along the course and quickly execute the appropriate Spell or Counter-Curse that fits the situation. It's not an easy task, especially when you have so little time to decide, knowing that your next move could mean the difference between life and death." 