BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
The Youtini Expanded Universe Ranking system is a 1-5 scale that ranks EU book quality, difficulty, and importance. Books closer to Level 1 are easier to read and understand, more important, and of higher quality.
Deep in the swamplands of the planet Mimban lies a powerful crystal, capable of giving its possessor an invincible mastery of the Force. In the right hands, it could save the galaxy. In the wrong hands, it could destroy it! While the explosion of the first Death Star still reverberates through the cosmos, Luke and Leia find that the war they thought they won was only a battle and that the dark side of the Force still stalks the galaxy.