Another website I frequent had a one day trivia league on Civilization the other day. The questions were pretty easy, but the real way to differentiate yourself was to predict which 5 questions would be the hardest for the field. The scoring is 15 points per correct answer with a bonus for your 5 chosen power questions of the percentage of players that missed it. I got them all but unfortunately predicted the difficulty poorly. The winner did extremely well, only leaving 1 possible point on the table. The link to the league is here (questions and answers on the right sidebar).