Unfortunately, a high level character can drink a carboy of poison, no matter his body chemistry, or other curious coincidences.
So no, the HPs can't support the "poison is ok, but 200' fall is not".
But here we are underlining that huge amount of poison aren't lethal.
That has nothing to do with the fact that drops of poison can be non lethal.
Again, if you think that 200' fall are lethal, you must make your game inherently coherent and make acid, fire, poison, giant's club hits and so on lethal too.
I have encountered more pools of acid than 200' cliff.
How many rounds should this "regular person" resist?
How many of them have taken hundreds of lethal hits and survived?
The same should go for the thousands of lethal menaces in D&D.
Does this mean that PCs never suffer a good hit?
What about their opponent's critical hits?
Stop there: why?
The same happens with many more variables, so what?
In real life no one would ever face a Trex, but in D&D a high level character can easily defeat it alone, and would know it.
If a high level PC get threatened by a dozen country bandits armed with crossbows he would never acquiesce to their demands, because he would know that he can single handendly defeat all of them in a bunch of rounds.
And how do you handle this scenario in game?
But what if the boulder's thrower hits with a critical hit, and the PCs failed his spot/listen/perception/whatever check?
I can't see how acid, fire, and so many other things could differentiate the damage between a wall and a barbarian.
Not to mention that luck isn't something related to living beings.
Divine intervention? Isn't it the deus ex machina that the "200' fall and survive" critics oppose?
24/7?
24/7?
You live in a wonderful world.
I have seen a high level character fail every save on poison and die. In DND not all poisons does con damage they so it it is very hard to kill someone with it. Strength and dex damage are not lethal. Also we have magical healing that deals with poison something that the real world does not.
In real life most poisons don't kill instantly some take hours, days, weeks even months. And a lot of poisons are not meant to be lethal they are meant to incapacitate.
Actually no I don't need to make all those things lethal. They already are if you run out of hit points and can not get magical healing. The assumption is that until you take enough damage to hit -0 you are dodging and taking glancing blows, shallow cuts but not lethal life ending injuries.
People survive horrible burns and acid attacks here in real life. In the DnD world with magical healing if you live through the fire and the acid and get magical healing then you are as good as new.
I hate hate the mechanic that allows high level characters not to be threatened by a dozen cross bows or bows aimed at them. I hate the meta gaming that goes on with it an if I could figure out a way to fix this bug I would.
Have you ever seen a the insides of a body that has fallen 200 feet? I have seen an autopsy done on a suicide victim. Almost every bone in the body was broken or crushed. These bones were pushed into the organs damaging some of them beyond any hope of repair. This person heart had literally moved to the other side of his chest tearing the aorta and causing them to bleed out into their abdomen in seconds. Their colon and intestines were ruptured in dozen of places. Their liver had been sliced in two both kidneys damaged to the point that they were useless. Major pieces of skull driven into the brain damaging major portions of it.
Knowing this I can't stand the way falling is done in DnD and which is why in my game you have to make a save or die. That way you do have a chance which represents people who have gotten lucky because they fell into mud, or something slowed their fall down.
In combat people have been shot dozens of time and lived because of where the bullets hit. People have been stabbed dozens of times and lived. This is how I look at damage taken in combat until you run out of hit points.
Personally I like Shadowrun better no matter what level you are or what class the same amount of damage will kill you. What goes up is your defense roll which allows you to avoid the damage in the first place. And I also like as you take damage you start taking penalties.
BTW in 30 years of playing I have only seen what pool of acid and the frakking thing had an acid shark in it.
DnD will never be able to be totally realistic. But we all have our WTFs and I think the game can support all kinds of play.