Psion
Adventurer
I think you need a few things to justify a new core class:
1) The class is fairly general and/or a strong archetype in the setting in question
2) The class would reasonably have first level members
3) The class could not be reasonably built using other class, skill, and feat selections.
A nice example of what is justifiable as a class and what is not is to examine the OA samurai and the CW samurai.
The OA samurai is essentially a fighter with fewer feats and more skills. In an asian game, the class is a strong archetype. You could build a pretty close attempt at the class with a multi-class fighter/aristocrat, but in doing so you make the archetype less appealing as a PC and more clumsy. I think in that situation, a new class is perfectly justified.
Now contrast this to the CW samurai. The class is essentially just a warrior with a built in two weapon fighting class. You could build the class by tacking a few feats on. There is no reason this class should not be a fighter. It's clutter.
It's generally easier to justify spellcasting classes, and to justify classes if you have a specific campaign model that removes classes from or otherwise alters the existing class set.
If a class is a specialized concept that starts out looking like one of the other classes, you should have made it a prestige class. A product I am working one a review for right now (Dezzavold) makes this mistake.
1) The class is fairly general and/or a strong archetype in the setting in question
2) The class would reasonably have first level members
3) The class could not be reasonably built using other class, skill, and feat selections.
A nice example of what is justifiable as a class and what is not is to examine the OA samurai and the CW samurai.
The OA samurai is essentially a fighter with fewer feats and more skills. In an asian game, the class is a strong archetype. You could build a pretty close attempt at the class with a multi-class fighter/aristocrat, but in doing so you make the archetype less appealing as a PC and more clumsy. I think in that situation, a new class is perfectly justified.
Now contrast this to the CW samurai. The class is essentially just a warrior with a built in two weapon fighting class. You could build the class by tacking a few feats on. There is no reason this class should not be a fighter. It's clutter.
It's generally easier to justify spellcasting classes, and to justify classes if you have a specific campaign model that removes classes from or otherwise alters the existing class set.
If a class is a specialized concept that starts out looking like one of the other classes, you should have made it a prestige class. A product I am working one a review for right now (Dezzavold) makes this mistake.