Dueling in Pottermore

Petrificus Totalus, the Full Body-Bind, as used in a duel on Pottermore. Source

     In order to duel in Pottermore, you must have first received your wand from Ollivanders (Chapter 5, Moment 4). To correctly perform a duel, you must click on the first letter or press its key on the keyboard; then, when the circle is at its largest, click or press again. When the white trailing line reaches the center of each letter, click it or press its key once for a circle to appear and once again when each circle is at its largest. After this is done for the last letter, you will be notified how well you performed and once both you and your opponent have finished your scores will be compared. Whichever one of you achieved the highest score will win, and if your opponent is from a different house the winner will receive 5 points for their house.

     The first trick to dueling is choosing the spell with highest possible score. Right now it is Petrificus Totalus, the Full Body-Bind, with the highest possible score of 145.

     The next most important trick is getting the rhythm down. The circle takes exactly three fourths of a second to grow to its maximum size, and the line takes three fourths of a second to travel between each letter. The most accurate method to get the rhythm down is to use a metronome. This online one works best for me. Set it so it matches the rhythm of the spell  (80 beats per minute), then click once every beat for each circle, and once every beat for the line that snakes between the letters. The rhythm for a perfect Full-Body Bind, for example, is like this (one beat per letter):

P P T T F F C C T T L L S S

Kind of like a horse clopping, isn't it? Now get out there and win some duels - unless you're not a Ravenclaw, in which case you really should just forget this post and never win a duel again.