When making a new class, you can either base it on your base faction, or an existing class. Question: can you base a lvl1 class on a lvl1 class? If yes, what is stopping you from doing that three times and maxing your class traits from the start?
top of page
bottom of page
Each class will tell you what level classes you can build off of. For Humanoids Level 1 are off of the base class, Level 2's are either from a Level 1 Standard Class or from your base faction, Level 3 from base faction, or level 1 or 2 classes, etc.
Most other domains build specifically off of the base faction.