the guynecologist, that's some great material on the subject, I'd also like to throw in Paul Neurath's earlier musings on the subject of "embodiment" in Ultima Underworld:
The Digital Antiquarian said:
https://www.filfre.net/2019/01/life-off-the-grid-part-1-making-ultima-underworld/
They kept coming back to the theme of
embodiment, what Neurath called “a feeling of presence beyond what other games give you.” [...]
It went without saying that Underworld must place you in control of just one character rather than the usual party of them. You needed to be able to sense the position of “your” body and limbs in the virtual space. Neurath:
We wanted to get a feeling that you were really in this dungeon. What would you expect to do in a dungeon? You might need to jump across a narrow chasm. You might expect to batter down a wooden door. You might expect to look up if there was a precipice above you. All these sorts of physical activities. And we tried to achieve, at least to a reasonable degree, that kind of freedom of motion and freedom of action.[...]
But I do take some issue with your "systems-driven emergent gameplay allowing for player agency" TL;DR, because I think it it's overly reductive to the emergent gameplay factor unless we complete it with "
for the purposes of embodiment." I'll use that instead of "immersion" because it's circular and carries a lot of baggage in these conversations.
Now, the reason I'm picking at this nit is that, very often when these discussions come about, participants bemoan the "immersive sim" term claiming it has nothing to do with "immersion." But it
does, it's right there in Stellmach's and LeBlanc's definition of the "immersive reality" philosophy and in Neurath's earlier thoughts on "embodiment" - while emergent gameplay is the critical vector, it's towards achieving that sense of "being there", similar to that of a tabletop RPG.
And this is such an important concept because it's essential to grasping the full vision that made those milestone titles what they were, that notion of comprehensive "embodiment" in an "immersive reality" achieved through mechanical design, of which emergent gameplay may be the foremost factor, but not the only one in a holistic approach. More concretely, the "immersive sim" as we have come to know it is a single-player 3D Action-Adventure game characterised by emergent gameplay systems and player agency, primarily First Person Perspective, low-abstraction mechanics and diegetic interfaces, and intricate, typically time-locked play spaces (as a consequence of development scope limitations), and it's the pursuit of Embodiment that makes the case for these implementations. From this perspective, you can draw a common line running through Ultima Underworld, Thief, Deus Ex, Arx Fatalis, System Shock 2 or Dishonored. Or even, albeit much more tenuously, STALKER or maybe Kingdom Come: Deliverance.
If I may harp on a little longer for the sake of completeness, I have occasionally encountered detractors of the "immersive sim" term mock whether that means the subgenre is related to other sims, such as space, mech, military or, hell, even racing sims, but while that's clearly not the case when quantifying the end result, there
is, in fact, a strong common element in terms of high-level vision. Deus Ex has more in common in terms of core design
philosophy (and only philosophy) with Assetto Corsa than with Call of Duty, even though when it comes to mechanical implementation, the situation is obviously reversed - both the immersive sim and the racing sim pursue giving the player a
comprehensive, individual, low-abstraction experience of acting out their respective fantasies, with the former being more of an "adventure simulator" or "hero simulator" in both presentation and - crucially - gameplay.
The name of the genre (or rather, subgenre), however confusing or unintuitive it might be to some, isn't really the relevant item here, the point is that we
do have use for a term reuniting the relevant titles and "immersive sim" did emerge to fill that role, at least until more recently, when games journalists started muddying things up with their usual, ignorant aplomb. If your buddy comes to you looking for recommendations after having just enjoyed Deus Ex, you might tell him to check out Thief or Arx Fatalis, but you won't immediately tell him to go play Skyrim (or Weird West). While there might be practical overlap in design and a common pedigree, there are significant departures in core vision there, part of which one of you guys (you yourself, if I'm not mistaken) recently quoted Greg LoPiccolo as outlining when it came to Thief:
"Essentially we're building a type of simulator," says LoPiccolo, "where object Interactions are correct and physics are tied in correctly, but not as weak as a Daggerfall thing, where there's zillions of NPCs in this large empty world."
As for the term itself, I'm not bothered if people want to change it to something else, but there is value in having one and "immersive sim" is simply what entered common use after Looking Glass. I dread the day when some game journalist comes up with "Deus Ex-like."