I don't know about some of you other folks, but initially I was pretty frustrated with Prospero's initiation test. At first, it seems nearly impossible to solve due to the fact that it's seemingly very random. How can mental acuity be tested by matching items that are always random? That's madness!
However, I was taught from a young age to fight fire with fire, so we will trade one evil for another in solving this test. That's right, we will be using some basic principals of probability (read: math) to outsmart the random placement of the cards. Take that, magic!
So, we already know the ground rules: If you mess up more than 3 times, you flunk the test.
There are 12 cards each, and each card needs to be matched with its identical twin, so really, what we're doing is sorting out 6 sets of 2 cards each. Each turn allows you to figure out what 2 cards are, and so you're bound to eventually find some matches on accident.
What you need to do is draw a grid matching the placement of the cards, so draw a grid with 4 rows going sideways, and 3 rows going down. Now, as you figure out each card's placement, write the first letter of each card on your grid so that you'll remember it later.
2 cards x 3 turns = 6 guaranteed opportunities to figure out card placements. It's worth noting that you can quickly find matches by marking up your grid as you pick the cards, thus increasing your amount of opportunities for matching by 2 every time a match is made.
Granted, this method might not get you all the cards every single time you do the test, but I've found it to be pretty useful in figuring out the parameters of the card placements.
Happy hunting!