At the beginning, every player is a generic diplomat. After a point in progression the player will have to seek out trainers to further specialize their diplomatic skills.
Diplomacy classes, along with their subclasses, are distinguished by their affinities to different areas of society, and their approach to the diplomatic parley encounters. Certain classes may be adept at dealing with the flattery and verbal jousting of court society, while others are more comfortable with a style of outright intimidation more suited to the underworld. And unlike adventuring classes, any race can choose any diplomacy class.
Diplomatic classes and subclasses included:
One of the Diplomacy classes. The Thug emphasizes threats, deception, bribery, and other shady methods to diplomacy.
The subclasses for Thug are Bureaucrat and Ringleader.
One of the Diplomacy classes. The Philosopher emphasizes Logic and Reason to diplomacy. Pholisophers will choose between the Arbiter and Sage subclasses.
There isn't much known about the role of the Demagogue as a diplomacy class. Judging from the definition of the word (Demagogue: A leader who obtains power by means of impassioned appeals to the emotions and prejudices of the populace), it is probable that the Demagogue will make use of the popular beliefs of the public, and use propaganda and logical fallacies in arguments.
The subclasses for Demagogue are Firebrand and Sophist.