On the one hand, I guess confining OSR to D&D and its close relatives allows the term to maintain some distinct meaning when discussing types of games.
On the other hand, using OSR as a playstyle description, it does not make any sense to confine it to games that are within X distance of D&D, system wise.
What if we had a different term for the playstyle itself. What could we call following the tenets of the Old School Primer regardless of game system, new or old?
I mean, I think if your motivation to play is based on following OSR principles, then a larger number of systems would be considered, for that campaign, to be OSR.
Basically, OSR as a playstyle, not as a particular collection of systems. If you use 1e to replay (rewatch?) the Dragonlance modules, for example, that's "Old School", but not OSR.
Tricky, as I kind of think that "What is the OSR play style" is potentially an unanswerable question. There have been several attempts to define the play style, dating back to
Matt Finch's Quick Primer, but they're all somewhat subjective.
Principia Apocrypha (Ben Milton, Steven Lumpkin, David Perry)
Skerples'
intro to OSR for new players
Google+ Discussion started by Scrap Princess, contributed to by lots of others- I like Patrick Stuart's list of 10 short principles at the end
You are right to note this - I often forget to credit the forum scene, as I was much more involved in the G+ and blog scene. It is of course where the term OSR first appeared, but I also don't really think it's where the OSR expanded and grew as much? My own biases perhaps. I am curious though how: A) intentional the forum OSR was - as in how intentional about forming a set of values or a play style, B) how much it actually focused on D&D and D&D alone, C) how much of it's focus was on what we would now consider old D&D - that is pre-1980 or so. I don't have answers, but my impression from reading back is that a lot of the earliest forum OSR was very happy with the sort of Trad style of TSR/WotC pre-3.5E. It was the 90's push towards even more highly restrictive design, illusionism and most importantly the shift to D&D as a tactical combat focused game that created the split?
Well, I think it's important to note that it started on the forums, because it was thing before retroclones came to be, and I've seen some folks treat OSR and retroclones as synonymous, which I think is definitely wrong. Despite its evolution or degeneration to being a marketing/publishing category, IMO that's just a sub-section that takes up a lot of space and attention and airtime nowadays.
I agree that the OSR movement really took off on the blogs, with tons of people exchanging ideas and expounding on their own, and explaining how they were putting them into practice. And offering lots of sweet gameable content for free! Some people really made a moral point about that (I seem to recall Kellri being vociferous about it, for example).
And from there Google+ became a haven for folks sharing even more, and enthusiasts in the scene playing in each other's games remotely. So there was kind of a hyper-acceleration of theory and practice within that community, but only for folks who were on G+. (I barely dipped my toes in it, mostly sticking to the forums and blogs).
Re: your A, B, and C, I don't think you're far off. I do think that there was a fair amount of variety in the game styles of the Old Schoolers. Lots of Trad, but also a fair amount of Gygaxian Classic. And once folks were on the forums swapping ideas, I think there was a tendency to start talking theory and comparing notes. Remember that AD&D mostly ruled the roost at first, with OD&D having a minority of partisans, and B/X gaining its huge mindshare later.
Philotomy's Musings was Jason Cone writing at length about how he used and thought about OD&D, both to new players and to AD&D fans who never got into OD&D or who had moved on from it long ago.
This here is true and I think it's one of the place where the the conception of the OSR as purely older D&D based breaks down. Even if one is working on a retro-clone, when one's play experience includes a number of other RPGs it pretty quickly starts to influence the retroclone, and discussion around it. I remember people in 2012 or whenever talking about Traveller style lifepath generators for their retroclones (or at least tables). Of course, yes the focus of most OSR spaces has been on B/X but I think that's partially a product of it's familiarity and ease of modification?
Sure, I think that B/X took over from AD&D and OD&D in OSR spaces because of its relative simplicity and clarity.
Most of us (at least in the US and UK) who started after '79 started with a Basic set of one iteration or another, but swiftly moved to AD&D because it was the "REAL" game. For grownups. With more complex and powerful options.
But because AD&D 1E's rules were so opaque and complex, basically everyone houseruled them and nearly everyone simplified them. A lot of folks coming back to D&D in the 2000s after 3E looked at AD&D and then looked again at B/X or BECMI and were like "Hey, turns out we just ignored the AD&D initiative system and used the Basic system the whole time". "I thought we were playing AD&D strictly but we actually ignored a lot of it. And B/X is less of a headache and looks like it suits my needs better."
OSRIC was the first retroclone because AD&D used to hold that OSR mindshare. But gradually, after it came out in 2005, B/X started taking over. And hence we see Labyrinth Lord and BFRPG in Jan and Feb of 2007 both implementing a simpler rule set more akin to B/X, but including popular concepts and options from AD&D.