I read that humans reach terminal velocity at 270'.
My personal falling rule for 5e is 1 point of damage per foot fallen onto flat hard surface (5'+), capping at 250. So raging high level barbarians are still fine, but it does get damage back to 1e-style norms. I went over to that after a low level 5e dwarf cleric fell 120' and walked off the 12d6. It feels about right. I have Large take x2, Huge x4 and Gargantuan x8, so elephants do actually splat when dropped from a great height.
I reckon I'll have Small take half damage (1 pt per 2' fallen) - it's not come up yet, but would be a nice boost for halflings & gnomes.
Edit: For 5e I tend to have most normal humans have at least 5-8 hp, I think that fits best with eg the animal stats. So a 10' pit is rarely fatal, unless you're a Wiz-1 with a CON penalty! By contrast in B/X RAW a 10' pit does 1d6 and an M-U 1 or Normal Man has 1d4 hp and dies at 0 hp, which feels a bit too 'world of cardboard' to me.
My personal falling rule for 5e is 1 point of damage per foot fallen onto flat hard surface (5'+), capping at 250. So raging high level barbarians are still fine, but it does get damage back to 1e-style norms. I went over to that after a low level 5e dwarf cleric fell 120' and walked off the 12d6. It feels about right. I have Large take x2, Huge x4 and Gargantuan x8, so elephants do actually splat when dropped from a great height.

Edit: For 5e I tend to have most normal humans have at least 5-8 hp, I think that fits best with eg the animal stats. So a 10' pit is rarely fatal, unless you're a Wiz-1 with a CON penalty! By contrast in B/X RAW a 10' pit does 1d6 and an M-U 1 or Normal Man has 1d4 hp and dies at 0 hp, which feels a bit too 'world of cardboard' to me.