Keldryn
Adventurer
I think that the multi-classing XP penalty issue is an artifact of the designers' intent not matching up with how people actually ended up playing the game.
Of course I can't say that I know what the designers originally intended, but I think I'm pretty close to the mark here. Multi-classing in 3.x was designed to replace and consolidate the non-intuitive multi- and dual-classing rules in 1st end 2nd Edition. Most multi-classed characters in 1st/2nd had two classes, with the occasional elf or half-elf Fighter/Magic-User/Thief (who advanced very slowly, dividing XP between three classes).
I don't think that it was the intent of the designers that players would build their characters with a level of this and a level of 3 or 4 other classes. Character classes were originally archetypes, not professions or lists of related abilities. The Fighter 3/Barbarian 1/Ranger 2/Rogue 2 character is not an archetype and I really don't think that the designers intended that Fighters would be played that way; multi-classing was included to allow a Fighter/Wizard or Fighter/Rogue class pairing.
Now, whether or not the multi-classing XP penalty was an effective means of restricting this sort of thing is an entirely different issue. I don't think that the designers saw the weakening of classes as archetypes that took place when they re-designed the multi-classing system. If the "2 or 3 levels in 4 base classes, 5 levels in one prestige class, and 2 levels in two other prestige classes" model of character building was what was originally intended, then they would have designed D&D as a point-based system, as that would have been a whole lot cleaner.
A first-level character is assumed to have spent several years in training to have acquired the entire "starting package" of his or her class; frankly I find it ridiculous that a character can simply take a level in a brand new and unrelated class as easily as taking another level in his or her original class. One could rationalize the XP penalty in terms of having spent 10 years training to be a Cleric and now suddenly trying to learn all of the basics of being a Wizard in the span of a few weeks.
As for the multi-classing XP penalty not applying to prestige classes... Well, it's never expressly stated anywhere but given that they were originally intended to be a DM tool for customizing the campaign, I would guess that the intent was that a PC would have one prestige class at most. The original concept of prestige classes was that they represented specific roles within the game world. This carries with it the implicit assumption that a character would actually have to make contact with an existing member of that organization or specialization and fulfill whatever in-world requirements for joining.
So that's my take on it. I think that the designers intended that a PC might eventually take levels in two base classes (three at most) and perhaps one prestige class. They re-designed the system to loosen up the overly-restrictive nature of AD&D but I think that they may have had blinders on and assumed that players would follow the same general model of character creation. The multi-classing XP penalty may have been a late addition, perhaps suggested by the same playtesters who wanted multi-classing restrictions on Paladins and Monks.
Of course I can't say that I know what the designers originally intended, but I think I'm pretty close to the mark here. Multi-classing in 3.x was designed to replace and consolidate the non-intuitive multi- and dual-classing rules in 1st end 2nd Edition. Most multi-classed characters in 1st/2nd had two classes, with the occasional elf or half-elf Fighter/Magic-User/Thief (who advanced very slowly, dividing XP between three classes).
I don't think that it was the intent of the designers that players would build their characters with a level of this and a level of 3 or 4 other classes. Character classes were originally archetypes, not professions or lists of related abilities. The Fighter 3/Barbarian 1/Ranger 2/Rogue 2 character is not an archetype and I really don't think that the designers intended that Fighters would be played that way; multi-classing was included to allow a Fighter/Wizard or Fighter/Rogue class pairing.
Now, whether or not the multi-classing XP penalty was an effective means of restricting this sort of thing is an entirely different issue. I don't think that the designers saw the weakening of classes as archetypes that took place when they re-designed the multi-classing system. If the "2 or 3 levels in 4 base classes, 5 levels in one prestige class, and 2 levels in two other prestige classes" model of character building was what was originally intended, then they would have designed D&D as a point-based system, as that would have been a whole lot cleaner.
A first-level character is assumed to have spent several years in training to have acquired the entire "starting package" of his or her class; frankly I find it ridiculous that a character can simply take a level in a brand new and unrelated class as easily as taking another level in his or her original class. One could rationalize the XP penalty in terms of having spent 10 years training to be a Cleric and now suddenly trying to learn all of the basics of being a Wizard in the span of a few weeks.
As for the multi-classing XP penalty not applying to prestige classes... Well, it's never expressly stated anywhere but given that they were originally intended to be a DM tool for customizing the campaign, I would guess that the intent was that a PC would have one prestige class at most. The original concept of prestige classes was that they represented specific roles within the game world. This carries with it the implicit assumption that a character would actually have to make contact with an existing member of that organization or specialization and fulfill whatever in-world requirements for joining.
So that's my take on it. I think that the designers intended that a PC might eventually take levels in two base classes (three at most) and perhaps one prestige class. They re-designed the system to loosen up the overly-restrictive nature of AD&D but I think that they may have had blinders on and assumed that players would follow the same general model of character creation. The multi-classing XP penalty may have been a late addition, perhaps suggested by the same playtesters who wanted multi-classing restrictions on Paladins and Monks.