From Introduction:
The world of Arthad is divided into kingdoms. In every kingdom lives a race who are direct descendants of one of the Galinor favorites, apart from Gadrath the Immortal who has no descendants. Most of the races are human, with rare exceptions that are not covered in this book. Humans are however not a single race but a number of races differing in many ways.
Not all of the races living in Arthad are presented there. You can choose to play all the races listed here except Zenith and Scinthy, although the Referee may allow you to play it. You’ll find the usual favored class for any race and a forbidden class. A Forbidden class means the race cannot take that class for role-playing reasons (i.e. a Drakand barbarian can’t be a literate cavalier), your Referee may, of course, change these rules.
In this book you will find several races, a new class and a basic explanation of how magic works. This helps you start the Seven Avengers Saga.
Clearly, we are more interested in the adventure, than the world, so rule changes are kept to a minimum. Only the races completely replace the classical races presented in the Player’s Handbook. The classes are the same except for Paladin who has been replaced by the Cavalier. The magic is the same but works slightly differently and you will find two new feats to handle it.