What about flying dragons, giant arthropods, fireball spells that exert no pressure, etc?
"Except where it is noted they are not", I wrote, under which all of these qualify.
As an extension of my magic-physics theory (which gets kinda detailed) creatures like raccoons and humans can live on a non-magic world but "fantastic" creatures cannot - they need magic in order to exist. As an extension of this, magic-based creatures such as elves and dragons will weaken, sicken, and die if stuck too long in a null-magic zone.
Nonsense. You don't need to assume that actual physics is true in order to understand the basic physical behaviour of dropped objects, running people, etc. Most human beings have understood the basics of these things for most of human history without access to either real or imagined knowledge of physics.
From the point of view of a PC or any other inhabitant of the game world, I agree.
From the point of view of the DM trying to design all this, however, I need to have it figured out.
As far as gravity is concerned, do planets in AD&D orbit the sun, or vice versa? What is the relatoinship between the earth and its moon, or the moon and the tides? In the real world, these are all manifestation of universal gravitation, but there is no reason to think this is so in D&D.
One could, if one wanted, redesign gravity so it works differently than what we're used to - but one would need a serious grasp of the physics and interrelations one has in mind in order to do this and have it come out working consistently. Far easier to just use what we already have, which already (for these purposes) works consistently and halfway predictably.
In other words, it's way easier to take what we already have and just bolt on what we don't have (magic, mostly) than it would be to start over from nothing.
Gygax suggests quite different possibilities in his DMG, and Spelljammer likewise does not describe a universe governed by universal gravitation.
For some non-prime-material planes things do work differently, no doubt there (says he who just finished running an adventure in the Astral, where gravity is a near-myth and time runs on chaos theory!). I'm 99% talking about the prime material with what I'm saying elsewhere in here, though.
Lan-"for some reason Spelljammer as a setting/system never appealed to me, even though the base concept is very interesting"-efan