Celebrim
Legend
So my initial question was wondering if that worked or "made [a common amount of] sense" today/with today's "modern" [meaning 3e-and-later] systems. Did the Cavalier as a separate class work...and does a Paladin, then, work as a subset of the Cav. or vice versa (with the assumption that both are a subset of "Fighter").
I've been engaged in rewritting the 3.0 classes to suit my own vision for what base classes should be like. Some of my guidelines have been:
1) Divorse the concept of each class from any extraneous cultural baggage so that there wouldn't be need to create a different base class for each real world inspired culture.
2) Try to move all the classes so that they come within a tier or two of each other, and particular none are tier 1 or tier 5.
3) Try to make each base class so diverse in its options that you would not expect any two players creating characters of that class to come up with the same concept. Or to put it another way, you could have a party of characters with the same character class, and each character would be distinctive.
4) Remove the need for Prestige Classes
The Cavalier in my opinion would complete fail all the guidelines I've set for myself. Worse, it would detract from the work I've been doing on the Fighter class by overlapping it in concept. I wanted to restore to the Fighter all the honor and breadth associated with the concept of a trained warrior or soldier so that if your core concept was, "A trained warrior." regardless of profession, regardless of social background, regardless of culture, regardless of specialization, it would make sense to implement the class as a fighter. I wanted to end the need for specialized classes for Knight, Samurii, Bushido, Kensai, Gladiator, Martial Artist, Pit Fighter, Cavalier, Warlord, Marshall, Hoplite, or whatever because in my opinion the need for such classes points to the fact that your base classes aren't well designed. The need for subclasses in my opinion points to the fact that your rules aren't particularly 'modern', as we now have plenty of means to diversify our classes without the need to create a new class with a fixed progression of abilities.
Along those lines, the Paladin also fails my guidelines at least in part because it carries too much unnecessary cultural baggage to be considered a base class. I ditched the Paladin class per se, and replaced it with the Champion class - a class derived in part from Green Ronin's Holy/Unholy Warrior classes.
3.X core classes that fail guideline #1: Paladin, Druid, Ranger, Monk, Barbarian, Paladin
3.X core classes that fail guideline #2: Cleric, Wizard, Druid, Fighter, Monk
3.X core classes that fail guideline #3: Druid, Barbarian, Monk
3.X core classes that fail guideline #4: Fighter. Monk. And in some sense, all of them, since almost any concept that involves a hybrid caster and non-caster class had to have a PrC built to accomodate it.
So, in answer to your question, I don't believe Cavelier makes sense in a modern context because:
a) It carries extraneous culture baggage.
b) It is not in my opinion a modern approach to build a separate base class to try to capture a narrow concept, a process that evetually lead to 2e having Cook and Blacksmith as classes.
c) There are techniques in the modern approach for styling your character to have a particular specialty within the base concept. For example, warrior implies mounted warrior is a possibility. Or similarly, warrior ought to imply aristocratic warrior is a possibility.
There are generally recognized to be 3 core classes in D&D - magical, martial, and skill monkey. For reasons of balance and flavor, magical in D&D is generally divided into arcane and divine. This gives us the four traditional core classe: arcane (Wizard), divine (Cleric), martial (Fighter), and skill monkey (Rogue). That's are minimum set, and a good argument could be made that you don't need more than that. Feel free to implement that if it suits you. However, many feel that some or all of the hybrids deserve a base class, for example divine/martial, martial/skill monkey, or arcane/skill monkey. Additionally, some classic classes have become iconic in and of themselves and players are going to expect that they can create characters that are distinctively of that concept without recourse to multiclassing. In 3e for example, the Barbarians rage became so iconic that pretty much anyone is going to expect to find some sort of Raging mostly martial/some skill monkey hybrid that lets them play what is now iconicly 'a barbarian'. Likewise, divine is generally split between Cleric and 'Druid' or arcane is generally split between Wizard and Sorcerer and some extent a need to need to also support arcane variants like Psion. I don't currently have a Monk class, but I'm increasingly feeling this sort of pressure on my rules set from people that (unlike me) feel the Monk is iconic, which may ultimately force me to provide some sort of 'Jedi' hybrid arcane/martial base class without the need to multiclass (Note, I don't need such a thing mechanically, as flurry of blows, stunning touch, etc. can all be handled in other ways.)
Anyway, I feel that the modern approach probably demands that there be between 4 and 15 base classes, none of which needs to be the Cavalier any more than we now need Acrobat as its own distinctive class. The cavalier existed because there was no way initially to customize fighters in an old school approach beyond selection of arms, armor and weapon proficiencies. Mostly I think that this was unsatisfying because the old school approach had no way of associating a background or skill set with a character in a way that consistently informed mechanical resolution. Old school was forced to move mechanical resolution into class specific notes in the adventure description, which notably procludes having meaningfu differences in background. Likewise, there was no old school way to define skillfulness beyond a class exclusive list of skills with a percentage chance of success, such as the thief. This in no way addressed a question like, "What is the chance you can bake a cake successfully?", and ultimately lead to silliness like having "Bake a Cake: 35%" and the implication that if you didn't have "Bake a Cake: 35%" in your class description, your chance of success was 0%.
We don't have that problem now. We can customize a character with a specialization and set of associated skills in order to mechanically tie background to process resolution.