Hit points are an abstraction signifying how robust and healthy a creature is at the current moment. Hit points mean two things in the game world: the ability to take physical punishment and keep going, and the ability to turn a serious blow into a less serious one. The hit points gained at higher levels reflect less a character's capacity for physical punishment and more his skill at avoiding hits, his ability to dodge and twist and turn. Each loss of hit points, in this case, suggests that he is becoming progressively less nimble over the course of combat—in other words, that the decreasing hit points are a marker for his overall endurance and condition.
So based on those three pieces of text taken from Pathfinder books, your hit points represent physical health, ability to roll with blows, ability to shrug off blows, and the ability to dodge. Interesting. Constitution applies to hit points, because Constitution represents your health and stamina, which tie nicely to hit points. It's interesting that Dexterity, which governs agility and reflexes, does not affect your hit points, which represent your ability to dodge blows. It's also interesting that the Toughness feat affects hit points, increasing your ability to dodge blows, but doesn't affect your AC, which is affected by the Dodge feat, which grants a dodge bonus to AC. Dodge doesn't affect hit points though, which is odd, because hit points represent your ability to dodge. It seems like a fairly easy call to make that Dodge should affect your ability to dodge. I'll email the developers, maybe we can get some errata. Improved initiative gives a +4 to your initiative checks because you have quick reflexes, but doesn't offer a bonus on Reflex saves, which are tests of your ability to dodge. Which is represented in part by your hit points and is increased by your Constitution, but not your Dexterity. Since your Constitution modifier increases your Fortitude save and your hit points, your Fortitude save is modified by your ability to dodge blows, but it isn't modified by Dexterity, which affects Reflex saves and your AC because you can dodge blows.
Damage you take depletes your ability to dodge blows and roll with blows and such. But cure spells restore hit points, so positive energy can restore your ability to dodge blows. Or at the very least restore the energy needed for all the nimble dodging you do.
Oh! Since your hit points represent your ability to dodge, when you put on armor, you should probably reduce your hit points, because now you can't dodge as easily. Since the max Dexterity bonus stat of a piece of armor represents how much dodging you can do in the armor, it should also probably represent the cap of your maximum number of bonus hit points. That's going to be rough. Can you imagine how many hit points a 20th level Fighter in full plate with an 18 in Constitution won't have? You don't have to imagine. 80 bonus hit points drops to 1 because he is wearing armor that affects his ability to dodge blows, and hit points represent your ability to dodge blows.
Back to cure spells. So positive energy can restore your nimbleness but cure spells can't fix exhaustion effects. That's odd, as you run out of nimbleness and flippy ninja shit because you get tired. I mean, if a dagger does 1d4 points of nimbleness negation, that's just an abstraction of you getting tired from dodging all the daggers. But cure spells restore that. But you're getting tired, so it's an exhaustion effect, not someone cutting you up into pieces, so if cure spells restore nimbleness, they fix exhaustion because you need energy to be nimble and dodgy. Hmm. That's weird that cure spells don't do that. I'll send another email.
So if cure spells restore stamina and nimbleness and rolling with blows and such, that's the damage inflict spells do. But the saving throw for inflict spells, which use negative energy, is a Will save. Will saves are governed by your mental capabilities. That doesn't seem right. Fortitude saves measure your ability to stand up to physical punishment and attacks against your health and vitality. So negative energy depletes nimbleness and vitality, but it is resisted by your mind. That's really odd. Shouldn't you then be able to make Will saves against damage if you can just convince yourself that you're fine? It's odd that you can't. I mean, if Will saves can resist damage to your body, I think Clerics are ideally positioned as the defenders of Pathfinder. Plus, they can deplete all the nimbleness and rolling with blows of all the people they are fighting against, because they can cast inflict spells.
Oh, but that's only if they're evil (or neutral). Wait a second. Only bad guys can use negative energy and only good guys can use positive energy. But the positive and negative energy planes have no alignment designation like the planes where demons and angels live do, and the race that actually inhabits the positive energy plane is kind of mean. Oh, and if you go to the positive energy plane, you can get filled up with some much nimbleness and rolling with blows that it kills you. This is very confusing. I think I'll just leave a Gmail draft open until I process all of this.
Negative energy animates undead, right? That's probably why it is evil, because there are all these undead sucking on the tit of the negative energy plane. Wait a second. Wizards can cast animate dead to create undead, which are animated by negative energy. So you have to be an evil (or neutral) Cleric to use negative energy to affect nimbleness and rolling with blows, but Wizards of any alignment can use negative energy. That's odd. Does that mean Wizards of any alignment can use positive energy? Oh. No Wizards of any alignment, not even neutral, can use positive energy. That seems like a gross failure of Wizarding schools. You would think you could just invert all the incantations and such and bam, now you're all nimbleness healing and damaging savants that can positive or negative energy at will without worrying about alignment. I feel like Wizards should work on that, they could give Clerics a run for the money as the healers of groups. But I guess that spot is open now because Clerics are taking over for Fighters because they can use Will saves to prevent damage. I feel like they'll have an easier time, they don't actually have to hit anyone with a weapon, they can just deplete their nimbleness with all their inflict spells until their enemies stop moving and stand still forever. If they're evil (or neutral!).
Hmm. This is getting complex. Charisma a measure of undead lifeforce and the lifeforce of undead is negative energy, which only evil (or neutral) Clerics can channel. So Charisma, and anyone that has a Charisma score, has undead lifeforce in them and is evil? That doesn't seem right. Hmm. But Charisma governs leadership qualities and personal magnetism as well as your ability to come up with reasonable arguments, lie, and scare people. Hmm. So I guess next time you're in the graveyard, don't kill that wight, he might come in handy if the Bard bites it and you need someone to negotiate a better price on rooms at the inn. Or I guess the wight might start flapping his dangling jawbone and convince that you should go kill the villagers instead of killing him and his rock star, politician, leader of men buddies. Oh but the Bard is undead too because he has a really high Charisma score. So I guess it doesn't matter.
Hmm. Undead get healed by the stuff that damages nimbleness and harmed by the stuff that restores it. But wait. Negative energy is the opposite of positive energy, which restores nimbleness. So undead have no nimbleness whatsoever and no ability to dodge, and no Constitution scores. Why are liches so hard to fight? They can't roll with blows or dodge. You should just be able to walk up to them and poke them with sharp things. Although, that might not have as much effect as I thought, they're animated by negative energy, so they're already out of nimbleness and ability to roll with blows. Hmm. This is really complicated, we might need to keep Fighters around so they can hit liches and undead and stuff.
I'm kind of concerned about Sorcerers. They have really high Charismas, that's a lot of undead lifeforce and opposite of nimbleness to have in one character. Hmm. With Sorcerers, Charisma is also the measure of the power of their bloodline. Wait a second. Blood is inside you. Bleed effects affect your hit points, which is your ability to dodge and roll with blows. Shouldn't magical bloodlines from your ancestors be based on your Constitution? Which measures your stamina and vitality and physical health and stuff? Rather than your undead lifeforce and your leadership qualities?
Ok, so leadership qualities are based on your undead lifeforce, which is your negative energy and ability to deplete nimbleness and rolling with blows. So if an evil (or neutral) Cleric can channel negative energy, shouldn't he get a bonus to his leadership score? I mean, he has all that undead lifeforce right there in the palm of his hand ready to deplete the nimbleness of his foes. It's right there. You can see it. He took it right out of the negative energy plane where all the anti-nimbleness in the universe is concentrated. Something's not right. This email is getting long. I hope they don't send the Golem after me for filling up their inbox with all these questions.
That reminds me. Golems don't have Constitution scores, but they're constructs, so they gain bonus nimbleness and rolling with blows because of their size. But big creatures have penalties to their AC because they're big and easier to hit. Is that like a sort of lucky clumsiness? Like they don't dodge well, but because they're so big and clumsy they trip a lot and it works out to being about as nimble as a normal living person (assuming the person has no Charisma, which measures undead lifeforce, which is negative energy, which is the opposite of nimbleness and rolling with blows)?
Hmm. Constructs are immune to energy drain, which is negative energy, which is undead lifeforce, which is Charisma, which is leadership qualities. So constructs can't have their nimbleness affected by anti-nimbleness or leadership qualities (which makes sense, because they're immune to mind affecting effects). But they still have hit points. But they're immune to having their nimbleness and rolling with blows depleted. So shouldn't they not have hit points? I mean, they are so nimble that anti-nimble can't affect them. Shouldn't they have super high Dexterity scores to represent how much they can dodge blows? Or super high Reflex saves and touch ACs? I mean, matter and anti-matter negate themselves when they touch, and constructs are so nimble and rolling with blowsy that anti-nimble and anti-rolling with blows can't affect them.
Thank Dog for scotch. Happy Frigg's Day, you fuckheads.