Upper_Krust said:
Glabrezu bigger than Balor
Dretch bigger than Quasit
Nycaloth bigger than Ultroloth
Yagnoloth bigger than Arcanaloth
Pit Fiend bigger than Dispater
Hellcat bigger than Erinyes
Advancing in caste is different from advancing in hit dice. It's the rule in the current edition that outsiders grow bigger as they grow in their "outsider class." Advancing in caste represents a complete transformation of body and spirit - the creature essentially "starts over" at that point. Although, I'll speak further on the relationship between demons and castes below.
These beings are the personification of their respective alignments. That in itself is an inherant predictability. I think you are nitpicking on the minutiae rather than appreciating the big picture.
"Predictability" is hardly the same as predestination! Your grasp on logic (or the basic meanings of words) is exceptionally poor.
Thank you, I guess, but my point was quite valid. Why can't an arcanaloth gain levels in sorcerer? Why can't a babau gain levels in rogue? You can't really justify a completely new yugoloth caste just to make an arcanaloth a slightly better spellcaster, and thus your rigid dogma falls apart.
If all demons could just take class levels then having castes that basically fulfill those criteria would be obsolete.
The thing you're missing is that demons are a chaotic race - not just chaotic, but a form of Chaos incarnate. They don't have a caste system like baatezu and yugoloths do - there's no overriding authority in the Abyss with the power or desire to limit their freedom in such a way. If a dretch wants to gain levels in rogue, there's nothing preventing it from making such a choice.
What you (and, occasionally, I) inappropriately refer to as "castes" are just adaptations to the infinitely varying planes of the Abyss. Somewhere there is a layer that's entirely populated by babaus, and they fill all roles in their hideous parody of a society. Babaus can advance to archdemonic status just by continuing to grow in hit dice, or they can shed their skins like a snake and become hezrou and glabrezu instead - but they certainly aren't forced to be rogues. They also make excellent assassins and shadow dancers, and could easily be mages.
Baatezu and yugoloths will generally conform to the expectations of their caste unless they become exiled from their respective societies, in which case they'll have no ability to change castes. Even here, there's going to be some variety - a barbazu can as easily become a fighter or a ranger as a barbarian, or join the Mortal Hunter prestige class from the Book of Vile Darkness. A yagnaloth might become a blackguard or take the Fiend of Blasphemy prestige class from the Fiend Folio. Each caste has quite a bit of wiggle room, given how many different classes and prestige classes are available in 3e.
Characters sgain class levels via EXP. Outsiders gain Hit Dice. Is it too much to ask for a mechanic for the latter?
It's unnecessary. One of the reasons the DM exists is to make decisions like this. Suffice it to say it takes centuries for a demon to grow this way if it ever does, and PC demons shouldn't have to wait that long. Let them use class levels!
From 1st Edition...unless I am remembering it all wrong.
You're remembering it all wrong. Nowhere in 1st edition did it say that
all demons and devils emerged from the souls of the damned (in fact, Glasya was implied to be the daughter of Asmodeus and Bensozia), and there was nothing that ever indicated that daemons had the ability to rise from mortal souls at all - they had no equivalent of manes or lemures. What's more, slaadi at least were clearly noted as reproducing sexually.
