The Academy currency is what I call duel points which can be used for retests and to by decks in deck shop. Also to buy gfx e.g signatures and avatars from gfx shop.
The ways to get DP:
Arena Duel Wins (Need a screenshot to prove it). It can be held in single or a match format.
Shadow Duels will get you more than normal (this needs a screenshot to prove it). This can also be held in a single or a match format.
For more information go on the topics made for these duels.
Another way to get points is posting and for every post you get 3 points which can be useful for a number of things. Check out the posting rewards system topic to find out more.
Also, more points can be obtained by participating in tournaments and how many points you get depends on the user that made the tournament.
Points can also be earned by completing dorm homework's depending on which dorm you are in. Homework will be set by dorm leaders and do not have to be completed unless you want points.
That is about all.
Have fun earning points!