Catching up on hit point calculations...

MrGoodkat

Hey there,

going to start a new game as a multi-classed fighter/mage soon. The question(s) this leads to is about hit point calculation.

As I understand it, the maximum HP you can get per level up are calculated like this:

Hit dice of class you are leveling up + highest* constitution modifier / number of classes, rounded down.

To give you an example, let's say we have a fighter/mage with 17 constitution, which gives us a +3 constitution modifier from being at least partially a fighter.

Hit point calculation on mage level up: [d4 + 3(fighter con modifier)] / 2 = max. 3.5, rounded down = 3 HP

Hit point calculation on fighter level up: [d10 + 3] / 2 = max. 6.5, rounded down = 6 HP

Level up on both classes simultaneously, e.g. at character creation: [d4 + d10 + 3 + 3] / 2 = max. 10 HP


Can you guys confirm this is the correct way it works? The thing I am most doubtful about is if it's really always the highest* con modifier that is used on level ups, but I'm 100% sure I recently read that in some BG FAQ.


So long,
Goodkat


*: Basically always the fighter con modifier, since all others are capped at 16/+2.

Debaser

@Mr Goodkat - Just add the hit dice together and then divide it by 2.

So 1D4 + 1D10 / 2.

THEN add +3 for every level in both. Since the class is a Fighter / Mage, you'll bet +2 every level as a fighter and +1 every level as a mage.

Every complete level should 10Hit Point MAX 1D4 / 2 + 1D10 / 2 + 3.

Easy peasy.

After level 9 for both classes you'll stop rolling dice and get flat Hit Points per level based on class.

+3 as a fighter and +1 as a mage. This might get limited to only the +3 as a fighter, I forget / have to look it up.

MrGoodkat

@Debaser

Are you sure it's calculated this way? What if had a +4 con modifier? Would it be divided evenly among my two classes?

So according to your calculation a lvl 9/9 fighter/mage with 17con would have a maximum of exactly 90 hit points, 99 with 18 con, 108 with 19 con and so on?

Debaser

@MrGoodkat YES that is correct. And I am sure about that, I'm just not sure about Multi-class HP gain after level 9, I know it's something fixed. It might be they add them both and divide them again. But I was googling and it looks like you just get 1 in each for 10 on....hrmn....someone needs to confirm that. Not that it matters that's a good base, especially if you turn the setting to easy when you level to get max HP.

MrGoodkat

Ok I'll take your word for it, thx a lot

Debaser

You're welcome man!

MrGoodkat

Now that I have actually tested it you must be wrong at *some* point. I started a new game with my Fighter/Mage and on my first Fighter level up the maximum number of hit points I can get is 6.

According to your calculation it would be 7, right? So maybe my initial calculation was correct after all..? Or is the constitution modifier just spread differently? I haven't received a Mage level up yet.

Hope you or someone else can help me out with this.

Freche

I could be wrong, but this is how I have understood the system.

The CON bonus is recalculated every time you level up or CON is changed, it's also divided by 2 for a duo multi-class.
Formula is (classlvl + classlvl)*CONbonus/2 , and always round down (ignore decimals)

So when you start out at lvl 1/1 with 17 CON you have 2*3/2 = 3 bonus HP
When you get your fighter level you have a character with lvl 2/1, formula gives 3*3/2 = 4.5

So at lvl 2/1you gain a total of 4 bonus HP from CON. Which is only 1 more then you had before.
When you hit 2/2 you will get 6 bonus HP. etc


As for lvl 10 and on, I believe the fixed number is also divided by number of classes you have multied. Though same as when you are rolling, minimum HP gain is always 1.
Which means when you are mutliclassing you will always only get 1hp from each level up when you reached level 10 (thieves at lvl 11)

MrGoodkat

Uhm... not sure I really understand what you're saying.

Currently I am 1/1 with 10HP and 17 con. When I do my first Fighter level up I get 6 hit points max. The only way this makes sense to me is by the following formula: (d10 + 3 con modifier) / 2 = 6.5, rounded down = 6 HP.

However that would mean that on my Mage level up I will get (d4 + 3) / 2 = 3.5, rounded down = 3.
That would leave me at a total of 19 HP at lvl 2/2 which doesn't really make sense since I am supposed to get a total of 10 HP every time both classes are leveled up.

Is it possible that the remaining 0.5 hp that are lost by rounding down are saved and added to the next roll?

As in
Fighter lvl: (d10 + 3) / 2 = 6.5, rounded down = 6, rest 0.5
Mage lvl: (d4 + 3) / 2 = 3.5 + rest 0.5 = 4

Edit: I just found this:

Multiclass

"Multiclass characters get the same XP and split it between the two classes,[5] but each time a class levels up, they receive half the hit points and Constitution bonuses that class would normally receive, or a third for triple class characters. IE, Jaheira, who is a Fighter-Druid, has 3,950 XP in both classes, and receives 100 XP for some quest, which levels her to 4,000 XP as both Fighter and Druid. This is just enough to get level 2 in each class, which is all done on the same levelup screen. She will get up to four HP (half of the eight that a normal Druid would) plus five HP (half of the ten that a Fighter would). Because Jaheira has three Con more than 14, she gets three extra HP per level, and this is halved for both classes, making each Druid levelup (8+3)/2 = five and 1/2 HP and each Fighter levelup (10+3)/2 = six and 1/2 HP. Half points are not displayed, making odd-numbered Constitution bonuses are problematic. So, for example, the Druid's maximum roll of eight, plus three, all divided by two is indistinguishable from a lower roll of 7+3/2. Half points carry on to the next levelup, so if the player is lucky enough to save a levelup with the maximum, and level up with maximum again, the extra half-points will be apparent, and our example Jaheira would get six HP for Druid or seven for Fighter. There are mods available which can modify or maximize HP gains."

Source: http://baldursgate.wikia.com/wiki/Class

So it seems I was right after all and half hit points lost on level ups are indeed carried on to the next level up!

Freche

The 0.5 looks like it's saved but it's actually not, instead it auto-corrects from time to time.
You can easily notice this if you make a triple Multi-Class and get some levels.

I know I'm bad at explaining things but I'll make another try

You have to treat your Class HP and your CON hp as two different things.

Class HP is what you gain every time your class gains a new level.
CON HP is a HP modifier that is added seperatly.
This is important to note, since this modifier affects your max HP not just during level up but at any point during gameplay, if your CON changes for any reason in your travels your max HP could be affected by that change.

Any rounding errors for CON HP will eventually correct themselves.
Any rounding errors for Class HP is lost forever and is not carried over to future rolls.
If you make a F/M/C with no CON bonus you can easily check this, at 1/1/1 he has (10+4+8)/3 = 7.33 HP. When you get a Cleric level (which is the one you will get first) you gain an additional 8/3 = 2.66 HP, but instead of having 10 HP you will have 9.


Assuming you always get max HP each level, your F/M will start with (10+4)/2 = 7 HP + eventual CON HP modifier

With a really low CON of 6 that modifier is -1hp/level
With a high CON of 17 that modifier is 3hp/level

So if we take the CON HP formula (classlvl + classlvl)*CONmod/2

At level 1/1 it should look like this:
with CON 6: (1+1)*(-1)/2 = -1
with CON 17: (1+1)*(+3)/2 = +3

Your actuall HP at level 1/1 (Class HP + CON HP)
with CON 6: 7 + (-1) = 6
with CON 17: 7 + 3 = 10


Now when you gain a Fighter level your Class HP will increase with 10 divided by 2 because your a multiclass so 10/2 = 5

Your Class HP is now 7+5 = 12

As for the CON modifier at level 2/1
CON 6: (2+1)*(-1)/2 = -1.5
CON 17: (2+1)*(+3)/2 = +4.5

we ignore the decimals so:
CON 6 = -1
CON 17 = +4

Your actuall HP at level 2/1
with CON 6: 12 + (-1) = 11
with CON 17: 12 + 4 = 16

Next time you will gain a Mage level which gives you an extra 4/2 = 2 Class HP, for a total of 12+2 = 14 Class HP

CON modifier gives us at level 2/2
CON 6: (2+2)*(-1)/2 = -2
CON 17: (2+2)*(+3)/2 = +6

Your actuall HP at level 2/2
with CON 6: 14 + (-2) = 12
with CON 17: 14 + 6 = 20

As you can see the CON bonus corrected itself.

I hope that is a bit easier to follow then what I first wrote.

TJ_Hooker

@MrGoodkat
Just in case what @Freche is saying is still not clear:
In the situation you're describing, the reason you're not getting as much HP getting to Fighter level 2 is this: first you get (d10/2), always rounded down. Then you (3/2) rounded down from your CON bonus. But you never lose HP from CON due to rounding errors, so that means that when you level up as a mage, you gain the remainder of your CON bonus, in this case 2 HP (in addition to the d4/2 you get from an additional level of mage). So you just have to wait until your slowest-levelling class catches up with your faster-levelling class in order to see the full benefit from high CON.

MrGoodkat

@TJ_Hooker: It's clear It's just his way of explaining that is very very complicated imho. For me it would have sufficed to say that half points resulting from con modifier are carried over while half points resulting from hit dice are lost forever. I appreciate the effort though!

Thx guys