Originally Posted by
Malakhim
I agree with this statement to an extent, which is why I brought up the idea of devices that create oxygen bubbles or whatever. In order to traverse underground, you should require certain types of gear to actually make it effective. Some kind of rudimentary scuba gear, a simple snorkel-like thing, air pockets in caves, whatever.
There's a limit to how much a person can realistically suspend their sense of disbelief, regardless of whether or not you're playing a fantasy game. There has to be SOME level of reality in there, or else you can't relate and thus immerse yourself.