AbdulAlhazred
Legend
Interesting. I think there are a lot of 'mixed' games. That is games often focus on specific areas and are fairly 'purist' in those areas, depending largely on the mechanics and character attributes and such to resolve situations, with the understanding that this will produce a certain kind of outcomes. I think this is the case with D&D combat, generally speaking, in its classical TSR forms (though I'm sure I need not point out that some of what you call HCS crept in with 2e particularly). Spells are a bit of a different beast there, having a good bit of rules structured character, but then overlapping into the OTHER, purely High Concept part of D&D where you have social interactions and various other things that are resolved almost entirely free-form (though again, interestingly 2e/late 1e adds a light flavoring of optional mechanics). B/X being noted as having an especially strong mechanical approach to exploration, which 1e shares, but 2e mostly elides.Rolemaster does not really purport to simulate a world. It is purist-for-system in the sense of the Right to Dream essay. Here's how these games are described:
These games' five-element structure is consistent: System + Color thereof, Setting, then Character + Situation. I'm trying to think of one which switches the role of character before setting, which might include some some superhero games. It might seem odd that Color is placed so high in priority, but consider the engineering-text model for the game text of GURPS - this is, actually, Color for System. . . .Purist-for-System designs tend to model the same things: differences among scales, situational modifiers, kinetics of all kinds, and so forth.
I think that Rolemaster might be another game that puts Character ahead of Setting.
The significance of this description becomes clearer when we see how "High Concept" or "genre" simulation is described:
At first glance, these games might look like additions to or specifications of the Purist for System design, mainly through plugging in a fixed Setting. However, I think that impression isn't accurate, and that the five elements are very differently related. The formula starts with one of Character, Situation, or Setting, with lots of Color, then the other two (Character, Situation, or Setting, whichever weren't in first place), with System being last in priority.
In other words, a system like RM or RQ - and also at least some approaches to Classic Traveller - prioritises system, a mechanical process of resolution which itself establishes colour and "theme" in the sense of focusing on those issues of scale, kinetics etc that are mentioned. The goal isn't to model a world: it's to make certain elements of the fiction salient, and to then have a mechanical resolution process that can take those as inputs and generate appropriate outputs. If the system breaks down when the parameters are varied even within reasonable limits, or if it needs intervention from a human operator to ensure that results "make sense", then the game is not doing what it is mean to do.
Whereas high concept/genre sim is quite different: the point of the PC build rules, for instance, isn't to produce mechanical elements of character that feed into a resolution engine: it's to produce characters with clear (and often colourful) descriptors which can then be fed into setting and/or situation. And there is a significant expectation of human operator intervention to make sure that those descriptors and that colour are respected in the outcomes of play. Every CoC or D&D module that has advice to the GM on what to do if the players miss a necessary clue, or every bit of advice about not rolling the dice and just going with what "makes sense" for the character, is something that would be out of place in purist-for-system play but is part and parcel of high concept sim play.
This is how we can tell that, within this taxonomical framework, 5e D&D is essentially a high concept/genre sim game. The closest D&D gets to being purist-for-system is if played in a type of AD&D style that differs from Gygax's own "skilled" play and focuses more on letting the system do its own thing for its own sake. The known problems with this are that AC, hit points, saving throws and even spell slots don't make much sense when looked at through this lens - they're hard to take seriously as "models" of anything in the fiction - and so the natural drifts towards vitality + wound points, armour as damage reduction, all take place, and we end up in the same general terrain as RM, RQ, C&S etc. I'm sure you're familiar with that drift because you were there the first time it happened in the late 70s/early 80s and have no doubt seen versions of it (even, on these boards, @Lanefan's versions) played out again and again and again.
Other games are pretty mixed as well. You've noted Traveller, which leaves you pretty much on your own in terms of things like navigating on a planet or exploring a ruin (though skills provide a small amount of structure). OTOH finding a patron, operating a vacc suit, or even the combat systems in general mix in a fair bit of system providing color.
I don't think it would actually be too hard to design something like a PbtA game this way either, where it had some very hard, what I call light process sim, rules structures, and then outside of that one particular focus the rest of the game could rely on some very general and typical PbtA moves. Like, you have really particular rules for racing your race car where all the various factors come into play, the moves are all detailed, focused, and realistic in terms of their descriptions and ranges of outcomes. Once you 'leave the track' you enter into the social and political world where its all much looser and more typical PbtA-esque play loop. One could feed into the other in terms of acquisition of resources, the effects of the character's personal interactions on their ability to focus, etc. sort of like what happens in Rush.