Conquest of the Horde

This might help. The one on Outland as well. And maybe the Great Dark.

tl;dr

Azeroth is one of many planets planes of existance waffles places pieces of existence in a string of others connected by the Twisting Nether and the Great Dark. Certain physics apply (gravity), but because of the chaotic nature of the Nether, even these fundamental things can be warped, usually with the use/aide of magic.

Azeroth has normal physics unless magic comes in, e.g - Kalimdor -> Thousand Needles or Twilight Highlands -> A fracture in earth, both locations have floating chunks of rocks but there's a purple/violet field below that keeps them floating, a source of magic can easily break the rules of gravity, mostly arcane.
But I came here to ask, anyone interested to talk about other physics than gravitational fields and what not, perhaps combat physics, weapons and what else can affect your character, if they exist or if they're more fantasy considering the game itself saying it?