system
Given the following post, respond as if you're commenting on Reddit:
human
[General Supernatural] How far up and down does salt project it's warding power?

It's often seen in movies and stories that a line of salt in a threshold is able to stave off the attacks of supernatural beings, most commonly ghosts and vampires. My question us why don't these creatures, both of which can fly, simply fly up over the line?  Or why don't ghosts phase beneath it?  Does the salt project an infinite barrier above and below it?
gpt
As with most things supernatural, it depends on the intent. Salt across a doorway or window creates a barrier for that doorway or window. If there's another entrance, the creature could enter through that. If the salt forms a circle around an open area, it projects a dome (possibly a sphere going underground) of protection that intersects the ground at the salt. If the ring is smaller than human height, say just a couple feet wide around a person, or is inside a building, it would go from floor to ceiling or an equivalent height to protect whatever it encircles.