Charisma scores of 17 or greater by fighters indicate the possibility of paladin status IF THEY ARE LAWFUL from the commencement of play for that character.That's all it takes to become a paladin -- be a Lawful fighter with Charisma 17+. By contrast, AD&D requires Strength 12+, Intelligence 9+, Wisdom 13+, Constitution 9+, and Charisma 17+. There are thus prerequisites for five out of the six ability scores, which would make the odds of rolling up a paladin using 3D6-in-order extremely slim.
Meanwhile, the OD&D monk (introduced in Supplement II) requires Wisdom 15+, Strength 12+, and Dexterity 15+. Those scores would be difficult to obtain using 3D6-in-order, I expect, but not quite as hard as what's required in AD&D, where the Strength requirement is boosted to 15+ and Constitution 11+ is added. Blackmoor also introduced the assassin sub-class, which Strength 12+, Intelligence 12+, and Dexterity 12+, as well as a neutral alignment (which is interesting in itself). Intriguingly, the AD&D requirements are slightly less stringent than those of OD&D, lowering it to Intelligence 11+ but changing nothing else. Druids in Supplement III have no prerequisites, while those in AD&D need Wisdom 12+ and Charisma 15+.
The Strategic Review also introduced several new character classes. The first was the ranger, which Intelligence 12+, Wisdom 12+, and Constitution 15+ in addition to Lawful alignment. AD&D tweaks these requirements. Strength 13+ is added, Intelligence becomes 13+ and Wisdom 14+, while Constitution drops to 14+. Illusionists in OD&D require 15+ in Intelligence and Dexterity; the AD&D version raises the Dexterity prerequisite to 16+. Bards in OD&D have no ability prerequisites whatsoever, which is in stark contrast to AD&D's expectation that they have 15+ in Strength, Wisdom, Dexterity, and Charisma, as well as Intelligence 12+ and Constitution 10+. Furthermore, the AD&D bard is a strange multi-class, requiring experience as a both a fighter and a thief before formally becoming a bard. The OD&D version is simply a class in its own right.
As others pointed out in the comments to yesterday's post, AD&D places a much greater emphasis on having high ability scores than OD&D does, so it's not unreasonable to expect stiffer entry requirements for some of the sub-classes. Likewise, 3D6-in-order won't make some of the sub-classes rare; it'll make them close to non-existent, especially for classes like the paladin, the ranger, and the bard. Given this, one wonders why AD&D continued to make a pretense of randomly rolling ability scores at all. This trend eventually reaches the truly absurd heights presented in Unearthed Arcana, where "Method V" for the generation of ability scores not only gives players weighted dice rolls (best 3 of up to 9D6 for key stats) but also states
If the total of the three highest die rolls is below the minimum requirement for an ability in a certain class, then the player takes the minimum number (e.g., 15 for a monk's strength) as the character's ability score.Let me reiterate that I fully appreciate that AD&D opted for a different approach to ability scores than did OD&D. At the same time, there's clearly a tension between the implications of having ability scores in a 3-18 range and the greater emphasis placed on having multiple scores at the higher end of that range. I'll grant that I myself prefer more mediocre characters, most of whose abilities are in the 9-12 range as you'd expect, so perhaps I'm innately ill-disposed toward looking kindly on AD&D's approach, but I don't think so.
One of the reasons I tossed out the idea of high ability scores having drawbacks as well as advantages is that I was thinking about AD&D and the importance it places on having high (15+) scores in multiple abilities. To me, the whole point of having modifiers for a range of scores is that there actually be a range. If the vast majority of PCs are going to have 15+ in their vital scores, you've devalued having a high score. To paraphrase Syndrome from The Incredibles, "when all ability scores are exceptional, then none are." On the other hand, as I've lamented in the past, I think LBB-only OD&D doesn't value ability scores enough for my taste. Most have minimal mechanical impact on the game, which makes me question the value of having them at all.
Ironically, I think the relationship between ability scores, bonuses, and sub-classes is an area that D&D III got right, or at least came closer to getting right. Bonuses generally appeared earlier than in OD&D or AD&D and there was a built-in capacity to improve ability scores with experience (though I'd have preferred a RuneQuest-like training mechanic myself). Sub-classes didn't have ability prerequisites at all, though some class abilities were tied to ability scores, meaning that having a higher score in its was better but not necessary. This made it possible to return to 3D6-in-order and plausibly create a paladin or a ranger (though I believe 3e adopted best 3 of 4D6 as the standard means of ability score generation). There was no need to the ever more ridiculous methods AD&D offered to ensure that every PC was not only exceptional but also sufficiently exceptional to qualify for classes with many prerequisites.
My point seems to have gotten away from me, I think. Suffice it to say that, the more I play OD&D, the less satisfied I am with AD&D's approach to ability scores and the role they play in the game. Mind you, I'm not wholly satisfied with the specific implementation of ability scores in OD&D either but I think its general philosophy is one I approve of, since it neither undermines genuine exceptionality nor does violence to the notion of a 3-18 range to describe normal human abilities. Anyway, it's more for me to ponder.