So several hundred posts and mostly it's devolved into game theory parsing of what the word "simulation" means, that we can't say that D&D has any simulation because a fighter can contribute to a fight against a dragon (the odds of a lone fighter beating a dragon are between slim and none)? Proof that a fighter couldn't kill a dragon is a video of a rampaging elephant that, while an impressive show of elephant strength, shows absolutely no one attacking the elephant?
I don't get too technical about definitions. Simulation just means we're consistently modeling
something. I could have a simulation of the two-dimension flat world which would look nothing like reality. D&D is not a particularly good simulation of reality, it takes too many shortcuts and compromises in order to make the game playable and fun. It lacks specific rules for all sorts of things that it
could cover because it was decided that it didn't add enough to the game and wasn't particularly relevant. So we don't have levels of blacksmith because it doesn't really matter.
But humans have been hunting and killing (to the point of extinction) megafauna for millennia. People that we would consider commoners in D&D go out to kill grizzly bears armed with
nothing more than a spear. Which brings us back to how tough is a dragon. Well, according to the MM, they have an AC 24. They're no more difficult to damage with a weapon than a well equipped human fighter with some help from magic that they're likely to have at 20th level. How much damage can it take before it dies? Well, since it's a completely fictional creature with no real world corollary, we know that as well they have over 500 HP. A dragon bites that commoner? Chomps them in half. Hits a high level fighter? The fighter deflects the majority of damage somehow because of their skill and training. The dragon has better AC than all but the best fighter with magically assisted armor and significantly harder to kill. But it's not an elemental force of natural destruction
in D&D.
We get misleading ideas of how difficult it is to kill animals from movies like Jurassic Park. No offense to the movies, I think they're decent popcorn fun, but hitting a T-Rex with several dozen bullets from a rifle at close range would likely kill it and would certainly injure it badly. If elephants were unkillable beasts of destruction, Hannibal would have conquered Rome. Some fictional versions of dragons are far better armored than tanks and virtually impervious to damage. They are not D&D dragons.
So I go back to my original statements. We are not simulating reality across the board. D&D world is a place of magic and toss in a lot of simplifications for ease of gameplay and fun. I assume that people heal magically quickly (even though I use gritty rest rules) and that HP measure exhaustion and stamina as much as anything. AC is over simplified, but you have to have some way of measuring how easy it is to damage an opponent, AC is good enough. People can't jump as far as the Olympic long jump distance according to the rules because those long jump rules are how far you can automatically jump with no effort under all circumstances, not just ideal ones. That, and people in D&D generally aren't effectively naked nor are they spending years to perfect long jumps to the exclusion of everything else.
Is D&D a particularly
good simulation? Probably not. To me the only way to say it's not a simulation at all requires having to redefine the word into some game theory construct or narrowly define what you're trying to simulate. Beyond that, the question is what reality do you want to simulate? How close does it have to be to the real world? For me it's action movie reality. I want it to feel like something I could see on a well done action movie or TV show that doesn't go to Superman levels of supernatural. Then throw in some magic for extra flavor and zing.
