You should know that I’m aware how PF2 works.
I apologize if I gave the impression you don't. I know you do.
I picked those values because they kept the example simple. It doesn’t matter whether there are modifiers or additional hits (from extra attacks or creatures). In a real situation, a PC would be considering the totality of the battlefield. If the sum total of incoming damage is less than one’s current hit points, then you can stay. If it’s not, then you have to decide whether to push your luck or take other measures to stay alive.
In Pathfinder 2, you can't make that assessment. You can go from max hp to 0 hp in a single round at any time. Sure it's not the average result, but it's not that you need extreme bad luck for it to happen.
In fact, it depends more on combatant decisions than luck. By this I mean that yes, sure, any foe scoring three criticals on three attacks will mess up your day, even if you're the most defensive Champion or the sturdiest Barbarian. But more importantly, if most or even half of the foes happen to target you, you will likely go down.
So unlike regular hp-and-level-based fantasy, in Pathfinder 2 you need to think much more "modern", more tactically. Just charging into the midst of combat, and the next round executing an awesome whirlwind attack that cuts down all the enemies in one fell swoop just isn't supported by PF2.
By I digress. My point was that this phenomenon is not caused mainly by criticals per se. Just the fact monsters hit more than they miss, and that they deal significant damage contributes more to this effect imho.
I’m also not talking about tanking. Tanking in D&D has always been a bad idea. The game is just not designed for it.
I agree. It's unfortunate, but I agree.
I've always felt there is an opportunity for a D&D-style game to support the Tank-DPS-Healer trinity popularized by World of Warcraft (only not as extreme of course). But a D&D game that finally drops the idea that fighters must automatically be best at BOTH attacking and defending.
You'd add design space, put simply. If a character needs to choose between tanking and damage-dealing and can't do both at the same time, the game can actually allow the tank to truly tank. In the current paradigm that'd be overpowered. But if the tank just isn't great at dealing damage, and thus needs damage-dealers (and healers), you'd strengthen the party bonds and let more people shine in cooperating to overcome the enemy.
(None of this means fighters can't be good damage dealers. As long as you can't do both at the same time, mission accomplished. In technical terms, allowing even fighters to respecc into damage dealers is fine. After all, being forced into a single role at character creation and then never being able to try out other roles during 20 levels is unnecessary and unfun)
The now-old Warcraft d20 stand-alone games were abject failures in this regard, since they didn't meaningfully change D&D to play more like WoW.
If you try to tank, you will burn through your healing very quickly. This is true even in 4e with defenders. If a defender takes all the hits, they’ll run out of healing surges, and the adventuring day will end prematurely. You want to spread the damage around.
Yes, I always found 4E healing surge rules extremely artificial and wonky. You really can't play a ranger or wizard the traditional way - staying out of trouble - since your healing surges are a significant party resource that needs to be put to use.
There were a lot of things I didn't like about 4E, but being compelled as an archer to move up to a monster just to let it bite chunks out of me only because I had chunks left to spare was near the top of the list... I mean, to a degree you're already advantaged by spreading incoming monster attacks over as many party members as possible (to avoid any single party member being overwhelmed) in every role-playing game. You definitely don't need a rule that significantly strengthens that compulsion. Luckily newer games drops that dreadful idea, so that the party can allocated all available healing to those that need it.[/QUOTE]
What I’m talking about is the above calculus: is this a dangerous situation (yet), and what should I do in response?
That sure is a worthy concept. But in Pathfinder 2, even an encounter rated "Low" is "dangerous" (per this definition) already before it started (at least at low level).
The game really does not support the idea that you should be given a decision point when you are supposed to evaluate "flight or flee". In official Adventure Paths, 99% of monsters are neatly packaged in encounter chunks so you know you're supposed to be able to defeat them.
Meaning that "yes, this encounter can drop me at any time, but I don't have to consider retreating because a combination of game mechanics will ensure that I will very likely prevail".
In fact, Pathfinder 2's selling point (if you ask me) is its ability to make nearly every fight into a tense nail-biter where you first reach the "we're doomed" stage, followed by the "heroic comeback" stage, followed by the "rout" or "mopup" stage.
As you can imagine, if the game is designed to maximize the thrill, it really doesn't support the notion that you should be able to predict the coming combat rounds and make rational decisions about staying or retreating.
Not only do very few iterations of D&D actually support retreat in any meaningful degree (it's nearly always up to GM fiat), Pathfinder 2 is all about every combat being challenging and exciting, yet ultimately surmountable. You basically need to trust the system to give you the tools you need to overcome even seemingly overwhelming odds - and the system actually does this.
But yes, it is meta when you're asked to take on fight after fight where you "should have" lost, yet nearly never actually do. Such a decision is clearly made by the player, not the character. The character is expected to act as if in an action movie. Indiana Jones never reflects on his multiple near-death experiences, he just throws himself into the next seemingly impossible situation. There's no room to roleplay your character asking rational questions in games designed with this philosophy.
I really think it is disingenuous (or ignorant) to argue Pathfinder 2 supports sandbox play (where characters roleplaying rational survival decisions is a cornerstone) out of the box. It just doesn't, on so many levels. This one is one of the less immediately apparent reasons why.