Considering games that:
* Has experience levels
* Has HP
* Has a stat that affects HP growth (I'll call it Vitality, but I've seen it with other names, like Constitution, Endurance, and even Stamina)

Those games can almost always be grouped into 2 categories:
* Non-retroactive: HP gains are based off Vitality at the time of level up. This means that, if you want to maximize HP gains, you need to raise Vitality as soon as possible. (You see this, for example, in Elder Scrolls games.)
* Retroactive: Your HP is determined entirely from Vitality and level, and the character's past history doesn't affect the character's HP. (You see this, for example, in D&D games from Baldur's Gate onwards (and sort-of in earlier ones, but it's complicated), as well as Wizardry 8 (and 1-3 and 5, but it's complicated here as well).)

What I am wondering, on the other hand, is if there are any games where you gain more HP if you wait to increase Vitality until your level is *higher*. In other words, to maximize HP longterm, you should hold off as long as possible before raising Vitality. (Perhaps HP gain when you increase Vitality is based off your level at the time of the increase.)

(By the way, if you're a game designer, are making a game that has those 3 characteristics, and are reading this, *please* use retroactive HP growth.)

Hmm, the closest I can think of are the Fire Emblem games, where you, if you want to maximize your stats, you usually wait with the promotion until you reach the max level of 20. But that only delayes the character boost through promotion and raises the probability on reaching max stats.

In FFXIII, you only gain access to higher HP increases in lategame, but that is just a simple pick and choose the stat and not based on calculations.

I feel like I am forgetting one specific game where that was a viable strategy, but on the other hand, you need very specific mechanics for that to be even a possibility.

That's not really what I'm thinking of.

What I am thinking of is the following cases:
1. Early vitality gives more HP than late vitality
2. Early vitality gives the same HP as late vitality
3. Early vitality does not give as many HP as late vitality

If we take a game where you allocate stats at level up, and let's assume that there's a cap on stats that is reachable, the situations would work as follows:
1. To get the best HP, you need to max out your Vitality as soon as possible.
2. It doesn't matter when you max out your Vitality; your final HP will be the same either way.
3. To get the best HP, you need to wait to boost Vitality at the last moment.

Every applicable game I'm aware of fits in case 1 or 2, and my question is whether there are any applicable games that fit case 3.

(I note that Fire Emblem isn't applicable to this discussion since there's no (changeable) stat that affects the rate at which HP increases.)

Well, there is. There is the growth rate, which can change in later games with class changes. So for example the unpromoted unit has a growth rate of 80, there is a 80% chance of getting one max HP with a level up. After the promotion, that growth rate could change to 120 and with that you gain 1 max HP guranteed and with a 20% chance a second HP.
And this higher growth rate can be gained by promoting a level 10 unit or wait until your unit is level 20. If you promote early, you gain the higher HP growth earlier, but you get less level ups and with that less max HP at the end. So waiting with the promotion is a way to gain more max HP at the end.

But if you demand there to be a specific stat that enables HP growth and you have to purposfully pick that stat for any HP growth, and you don't know any game like that, then it probably doesn't exist.

Games with a stat you have to purposely pick for HP growth do exist. See TES 1-4 for example, where Endurance affects HP growth.

I just want to know if there's any game where you will end up with more HP in the long run if you wait until higher levels to boost the stat rather than boosting it early.

A thread which was split into many spam threads.

I think Pokemon kinda works this way.

But on the other hand, the way stat gains work in Pokemon are downright mysterious and baffling but to only the biggest Pokenerds.

No.

Assuming equal DV/IVs and EVs, two Pokemon of the same type and level will have the same HP (and the same is true for other stats). It does not matter whether the HP EV is raised early or late. (Though, at least in early generations, you might need to deposit and withdraw the Pokemon for the effect of EVs to apply.)

(I actually do have a good idea of how it works; the game starts with the species base stats, adds the DV/IV values, adds some function of the the EV (stat XP) values, and then scales it according to level. Note that EVs were changed drastically between Gen 2 and Gen 3; DV/IVs were changed, but not as drastically.)

You forget about Natures and other factors to the mysteriousness that I never cared about and wish they had culled along with the slog of a raw turn based system.

I believe Natures are just a percentage modifier, and there's no reason to ask *when* a Nature is acquired.

Also, what alternative to the "raw turn based system" would you suggest that would not hinder accessibility?

I can't think of any. I suspect it hasn't hit the mainstream because if it had any meaningful impact, the vast majority of players would find it wasn't a fun mechanic and would be a little frustrating (it's basically a form of the glass cannon trope - it would encourage building stats in other areas so that you had a weak character dealing a huge DPS. Conversely, it would then make the end-game really easy). Of course, you could avoid this by reducing the impact of the ascending health increase as the game progresses, but then you've got a quirky mechanic that doesn't really do anything.

If you're building a game with this in, I'd be intrigued to see how that mechanic was received.

Honestly, I consider non-retroactive HP gains to not be a fun mechanic, and yet it keeps re-appearing (in major releases at least as late as Oblivion, and possibly even later; D&D 3.x and games based on it have a similar issue with non-retroactive skill points from intelligence). Such a mechanic overly favors building more tank-y characters early on, which can lead to fights taking longer which is not fun to play, though perhaps the worst aspect is the amount of micro-managing that's required to optimize HP gains in such systems.

The RPG I'm thinking of making will definitely not have non-retroactive or what I'm calling "reverse non-retroactive" HP gains. Actually, it's unlikely to have XP-based levels, as I find that to be an overused mechanic that's gotten old, and (particularly when combined with skill points gained at level up) has its own set of flaws. As a result, HP gains won't be tied to level. (I note that Final Fantasy 2 *technically* has non-retroactive HP gains; however, that game has no levels and hence no limit on the number of times HP can increase. The difficulty of getting more HP is solely based off how many HP you have (and how much you lose during a battle), so low Endurance characters can eventually catch up with high Endurance ones if they're taking comparable damage. I actually really like FF2's HP growth mechanic, as a matter of fact.)

Please don't take this the wrong way, but while I think your comments and preferences are completely valid and I have a lot of respect for them, you certainly have a very niche interest in certain types of RPGs and mechanics. This is not a bad thing, but it does mean that your preferences aren't aligned with the mass market - so it's going to be hard for you to find something commercially that meets your preferences.

That being said, again, if you can make the mechanic meaningful whilst avoiding getting into an unfun glass cannon (i.e. who strikes the first hit wins), I would be interested to see how it's received and whether it's a commercial success.

As I said, this isn't a mechanic I'd actually want to put in a game I would make; I'm just curious if there's any RPG out there that works that way. Also, my preference isn't for "reverse non-retroactive", but is more for retroactive HP gains, which reduces the micromanagement and is actually friendlier to players, as it means the order in which you raise stats isn't important in the long run. (In other words, raising Vitality early on would be done because the player is dying too easily, not because it will give more HP in the long run.) Also, retroactive HP gains avoids the missable stat priblem that the other two approaches I mention have.

Glass cannon set-ups can be fun, though it's more likely to be fun in action games rather than in (non-tactical) RPGs. (Castlevania: Order of Ecclesia has one item that turns you into a glass cannon; your stats (including defense, interestingly enough) increase greatly, but you die if you get hit *at all*.)

Sounds like a bit of difficulty inversion.

With that said, I don't actually like having items that increase stats if they happen to be equipped at the time of level up. (That's one issue that Final Fantasy 6/9 have. In fact, on the rare occasion that I replay FF6, I actively avoid esper stat bonuses; avoiding them makes stat differences between characters more important, and you don't need the stat bonuses even casually.)