Grog said:
Because in real life, all other things being equal, someone who's taken a non-superficial wound doesn't fight as well as someone who's unhurt.
I wish I could find the link I saw a while back, but apparently this isn't exactly true. Because of adrenaline and various other body reactions many fights tend to go something like: fine, fine, fine, fine, - down or dead.
Even if they didn't - I don't like death spiral effects in my heroic fantasy.
But to the OP:
Let’s assume a 10th level fighter with 15 con and average HP's so 82 HP's. Now by 10th level the fighter is significantly above just about everyone else in the realm he's seen and done a whole lot and presumably knows how to take a fall.
He falls 100 ft - average damage 35 max damage 60 - he'll survive at various levels of ok but unless a cleric gets to him he will be significantly weakened by the ordeal. Is this a problem in heroic fantasy - not to me, I consider a 10th level character to have build up a little karma and or know how to slow a fall to a huge degree.
If he falls a 200+ feet his chances are much worse. Now he only has a much smaller shot of walking away from it and even if he does, he'll be at a huge deficit. And again I just don't see the problem for heroic fantasy, if anything chance of death is a little too high.
If you want grim and gritty, lower the massive damage cap and increase the fort save for massive damage from the fall.
If you want a really random maybe ok maybe not feel, just take 1 die and multiply instead of rolling all the dice (so 10 feet 1d6, 50 ft 1d6x5 100 ft 1d6x10 and 200+ 1d6x20) most players will take this kind of chance only in an emergency.
[edited to fix faulty math]