@pemerton - Wonderful post.
I think you can take your outline above and continue to unpack it a variety of profitable ways. First, I think there is something interesting, perhaps several interesting somethings, to examine that stem from your A, character building as a site of challenge, that index pretty clearly some of the elements of the evolution of play in D&D. Second, I think in the case of B, D&D suffered somewhat from being the hippo in the bathtub when it comes to responsiveness to the changing tides of the lager industry. In both the above, I see traces of the difference I was attempting to describe.
I think that one useful way to talk about the evolution of roleplaying from the 70's through, say, the 90's, is to characterize it as a discussion, or a discourse, that existed between D&D on the one hand, and the rest of the industry on the other. D&D was during that time, I think, the yardstick by which the industry defined itself. At least I don't think that's a controversial way to describe the situation. That discourse is interesting because I see it as oddly one-sided. A lot of companies were either producing games that could be described either as "D&D but..." or as "not D&D because...". I'm not trying to trivialize the work of other designers with that characterization, but I do think that design questions like "what do I want my game to do?" or "what is actually important about the gaming experience?" that other games were at least in part designed to address do indeed come from a departure point of D&D as the "model from which". Differently from these other games, D&D was in the process of becoming "more D&D than before" rather than adjusting to any outside influences.
When you look at where D&D ended up in it's 3rd edition in terms of your A, character build as challenge site, I see a clear evolution at work. The complexity of character creation, and the impact of what we like to call system mastery, became pronounced. The ways in which characters interacted with the diagetic framework became increasingly granular as skills, proficiencies, and abilities multiplied, and the search for synergy in that ever expanding bin of granularity became the chief challenge facing players during character creation. What did not change in this movement, and what in fact receded in some ways, was any notion of player interaction or agency within the fiction that fell outside this ever-expanding set of rolls and skill tests. The way in which D&D evolved was to produce more and more specificity and volume in the set of things that could be rolled for, and more and more variety and complexity in the ways in which players could design their characters to provide bonuses to whichever rolls they felt most important. Players were challenged to define their characters in terms of bonuses to the rolls that reflected what the player felt their character should be good at. The teleos of this evolution, in terms of play, is that players wanted to roll dice to do things. Interaction with the fiction become, I would argue, more about choosing what to roll than about determining if a roll were the right tool. To put this evolution in your terms, I think D&D very much collapsed in the direction of 1 as it 'B'-ed. This focus on skills, and more generally on die rolls as the primary diagetic tool, serve in some ways as a deterrent to exploring other ways to play the game, and other ways to apportion control over the fiction. Not an overt or explicit deterrent, but one that works by shining a very bright spotlight elsewhere.
This has gotten long, and I need a cup of tea, so I'm going to put a pin in my discussion of hippos and bathtubs and come back to it later on, should that still seem like a useful avenue of discussion.
I think you can take your outline above and continue to unpack it a variety of profitable ways. First, I think there is something interesting, perhaps several interesting somethings, to examine that stem from your A, character building as a site of challenge, that index pretty clearly some of the elements of the evolution of play in D&D. Second, I think in the case of B, D&D suffered somewhat from being the hippo in the bathtub when it comes to responsiveness to the changing tides of the lager industry. In both the above, I see traces of the difference I was attempting to describe.
I think that one useful way to talk about the evolution of roleplaying from the 70's through, say, the 90's, is to characterize it as a discussion, or a discourse, that existed between D&D on the one hand, and the rest of the industry on the other. D&D was during that time, I think, the yardstick by which the industry defined itself. At least I don't think that's a controversial way to describe the situation. That discourse is interesting because I see it as oddly one-sided. A lot of companies were either producing games that could be described either as "D&D but..." or as "not D&D because...". I'm not trying to trivialize the work of other designers with that characterization, but I do think that design questions like "what do I want my game to do?" or "what is actually important about the gaming experience?" that other games were at least in part designed to address do indeed come from a departure point of D&D as the "model from which". Differently from these other games, D&D was in the process of becoming "more D&D than before" rather than adjusting to any outside influences.
When you look at where D&D ended up in it's 3rd edition in terms of your A, character build as challenge site, I see a clear evolution at work. The complexity of character creation, and the impact of what we like to call system mastery, became pronounced. The ways in which characters interacted with the diagetic framework became increasingly granular as skills, proficiencies, and abilities multiplied, and the search for synergy in that ever expanding bin of granularity became the chief challenge facing players during character creation. What did not change in this movement, and what in fact receded in some ways, was any notion of player interaction or agency within the fiction that fell outside this ever-expanding set of rolls and skill tests. The way in which D&D evolved was to produce more and more specificity and volume in the set of things that could be rolled for, and more and more variety and complexity in the ways in which players could design their characters to provide bonuses to whichever rolls they felt most important. Players were challenged to define their characters in terms of bonuses to the rolls that reflected what the player felt their character should be good at. The teleos of this evolution, in terms of play, is that players wanted to roll dice to do things. Interaction with the fiction become, I would argue, more about choosing what to roll than about determining if a roll were the right tool. To put this evolution in your terms, I think D&D very much collapsed in the direction of 1 as it 'B'-ed. This focus on skills, and more generally on die rolls as the primary diagetic tool, serve in some ways as a deterrent to exploring other ways to play the game, and other ways to apportion control over the fiction. Not an overt or explicit deterrent, but one that works by shining a very bright spotlight elsewhere.
This has gotten long, and I need a cup of tea, so I'm going to put a pin in my discussion of hippos and bathtubs and come back to it later on, should that still seem like a useful avenue of discussion.