page 72 of APG says that I can take multiple archetypes as long as they don't alter the same class features. A Paladin can not be a hospitaler and an undead scourge because they both modify smite evil and replace aura of justice. But s/he can be an undead scourge and a warrior of the holy light since none of their new class features replace the same core class features. How exactly does this work? Also what about starting as an archetype for a few levels then switching to core class for the rest of the progression. I've looked on the boards and I can't find any answers to these questions. I'm very interested in starting as a beast master ranger for four levels than switching to core ranger before I lose camoflauge. Can this be done?