I've previously described a distinction between fiction-first and D&D-like TTRPGs as the 'locus of simulation'.
Basically, my theory runs, in (many) D&D-style games (which often have a heritage of battle/wargames) tend towards a simulation of the actions of characters within the world (and the world itself), and fiction-first TTRPGs (e.g. Powered by the Apocalypse games) are more about simulating a particular piece of fiction. This is evident in the tools each gives its players, and often additionally through the sense of shared authorship/vs architected underlying reality that runs through them.
(I highly doubt this theory holds up to a truly robust kicking; rather, I've found it an interesting lens to clarify the distinction/strengths in my own mind.)
I bring it up (yet) again because it was (yet) again on my mind over the weekend. I had cause to look up 5E's 'stealth in combat' rules (yet again...) and found that they were a) simpler than everyone seems to think but b) run consistently against people's mental conceptions of how that should work in a world simulation.
I won't turn this into a dissection/reiteration of those rules, but it had me flashing back to my earliest days of D&D, haggling over things that 'didn't make sense' in the rules with people arguing about what they felt they should be able to do when looking at the situation logically. (Which never came up when the rules did allow them to do something that didn't fit with that same logic.)
This is one of the major shortfalls of the D&D* approach, for me.
- The rules themselves often seem precise because they are seeking to so specifically simulate various different aspects of the world and its characters, say, what it means for one to be hidden from another.
- But the rules are a necessarily imperfect and simplified abstraction of those things (which also have considerations such as game balance).
- But what we encounter in a successful [by my metrics] game is a kind of immersion in the fiction more where players don't see things so much as a more straightforward 'tabletop battle game'.
- Which leads to regular situations where we have an intuitive sense of what the world-state should look like and what action should be possible that doesn't match what the rules tell us. Usually, in the case of my stealth example, that's on one extreme end of 'your enemies don't just forget you exist because you've briefly disappeared from view' and 'I should be able to use the Hide action all the time because they're facing the other way fighting Bob.'
- Neither of those examples are actually things the D&D stealth system cares about (it's not about them not knowing you're there -- it's about them not being able to see you; 'facing' isn't a standard 5E concept).
- And the answer is often just 'ignore those rules that get in your way', which is all fine and good but can run into other considerations I won't get into here.
My point isn't really about stealth in 5E. It's to illustrate what I mean when I talk about the 'locus of simulation'. D&D* can end up tripping over itself trying to give us comprehensive enough rules that they feel like they're simulating elements of a physical reality, but not so overcomplex they become cumbersome. (Which can lead to a kind of 'uncanny valley' where our immersion in the fiction rubs against rules that seem more precise than they are.) Whereas other, fiction-first systems don't care about that in the same way. Hiding from someone in combat might have no rules, or use some other piece of rules that more closely represents what it is trying to accomplish in the fiction.
What I realise when coming to the end of this shard and being out of time is that there is some connection to the idea of naturalistic vs non-naturalistic representation of rules and fictional acts. But I'll have to dig into that thought another time.