Check this latest blog from James at GROGNARDIA:

https://grognardia.blogspot.com/2024/03/dice-for-accumulative-hits.html?m=0#comment-form

Now, I've ALWAYS figured h.p. by taking the hit die for that class and adding the result to the total (Con bonus as well) when going up a level.

But read the article. We MAY have been doing it wrong. This is mind blowing to me.

I posted my reply there, but I'm curious about your thoughts.

Kevin Crawfords "... Without Number" games all use this method.

As far as I can tell, the intent in AD&D and Basic/Expert is that you roll the new dice and add to the current total.  I'm not at all sure about OD&D.  Also, the variant of rerolling the entire set and taking if higher has been a house rule in D&D I don't know how long.  It was old when I first encountered it in the mid 80's. 

My own system does hit points with that variant, which is something I picked up from those old house rules.  It works great when doing random rolls at smoothing out a string of bad luck.  The other thing I like about it is that it effectively means that hit points don't go up every level.  This has some kind of minor psychological effect on players' attitudes towards leveling that I find positive, albeit hard to pin down.

Quote from: blackstone on March 19, 2024, 01:00:24 PMNow, I've ALWAYS figured h.p. by taking the hit die for that class and adding the result to the total (Con bonus as well) when going up a level.

But read the article. We MAY have been doing it wrong. This is mind blowing to me.

I posted my reply there, but I'm curious about your thoughts.

I've been playing OD&D this way for years now. There are several advantages to re-rolling all your hit points each level instead of the usual roll and add method:

1) By rerolling, you balance out bad rolls, especially bad rolls at lower levels.

2) Using this method means you can give out bonus hit points at first level without affecting the hit point total at higher levels. I've been starting all characters with hit points equal to 1/2 their Con score. Often magic-users won't gain any new hit points until 3rd or 4th level while fighters might have a higher total at first level.

3) It greatly simplifies multiclass characters. Each time you gain a level in a class, you roll that classes hit die total. So gaining a level in magic-user will often not result in more hit points. This also allows me to adjust XP so that the levels of the various classes in a multiclass character don't need to be equal. A FTR 8/MU 4 works just fine. (in a way this is very similar to AD&D's dual class rule)

Finally, I've implemented a rule change for "level drain" to make it "hit point drain" instead. A character hit with a draining attack will permanently lose hit points. These will be recovered as the character levels up. But, since the new current total is lower, it is possible that a bad hit point roll might not recover all the lost hit points. But, in any event, as the player levels up he will gradually fully recover.

Quote from: Steven Mitchell on March 19, 2024, 01:17:54 PM
As far as I can tell, the intent in AD&D and Basic/Expert is that you roll the new dice and add to the current total.

In doing research, it looks like Gygax always used the roll and add method whereas the reroll all dice method was used by Dave Arneson's group (hence it's appearance in Empire of the Petal Throne).

And you are right about not always gaining hit points. If a character gets a really good roll, he might not gain more hit points for the next few levels.

Yea, I can't speak to whether that's the original intent, but its definitely the variant I like to use the most, I see it in a lot of OSR games, and its completely possible it dates back to the beginning.

well then....i've been living a lie. 

Good old jmal late to the party by about 30+ years. I remember this being discussed on rec.games.frp when I was in undergrad, and I'm sure this discussion took place in some old APAs in the late 70s.

One thing I read a long time ago (source unknown, maybe some blog?) talked about this at length and how the 1+1 meant the fighter character was higher than a 1 hit-die creature, which means monsters wouldn't get the multiple attack routines they would otherwise get against low-levels. Just having the fighter around meant you couldn't be hit fifty times in a row by some high level monsters before you even had a chance to react.

Quote from: Brad on March 19, 2024, 02:11:21 PM
how the 1+1 meant the fighter character was higher than a 1 hit-die creature, which means monsters wouldn't get the multiple attack routines they would otherwise get against low-levels. Just having the fighter around meant you couldn't be hit fifty times in a row by some high level monsters before you even had a chance to react.

Interesting, so the +1 on the hitpoints was a way of setting figters above 1HD monsters without giving them a whole extra hit die, I can see that. Kind of like the xHD* that monsters would get for purposes of XP.

Quote

Quote from: Steven Mitchell on March 19, 2024, 01:17:54 PM
As far as I can tell, the intent in AD&D and Basic/Expert is that you roll the new dice and add to the current total.

In doing research, it looks like Gygax always used the roll and add method whereas the reroll all dice method was used by Dave Arneson's group (hence it's appearance in Empire of the Petal Throne).

And you are right about not always gaining hit points. If a character gets a really good roll, he might not gain more hit points for the next few levels.

I'll stick with the Gygaxian "roll and add" method. Honestly, there really isn't any right or wrong, and long as you're consistent in the game you run.

I do find it funny and interesting that after all of these 40+ years I've learned something new about the game I thought I knew so much about.

The table itself dioes kind of hint at that being the case. A level 1 fighter has 1+1 HD. When 2nd level is reached and the new HD total is 2, if you didn't roll 2 dice what is the alternative? Roll 1d5 and add? B/X made the added dice per level a bit easier with even numbers. On one hand you are guaranteed to get more hit points at every single level but if you roll a 1 or a 2 at first level then you stuck with it.

This got discussed in Dragon somewhere and someone clarified that it was additive. Not reroll every level.

I still want to know why characters don't get their zero level hit dice like everyone else does.

Quote from: Exploderwizard on March 19, 2024, 07:47:44 PM
The table itself dioes kind of hint at that being the case. A level 1 fighter has 1+1 HD. When 2nd level is reached and the new HD total is 2, if you didn't roll 2 dice what is the alternative? Roll 1d5 and add? B/X made the added dice per level a bit easier with even numbers. On one hand you are guaranteed to get more hit points at every single level but if you roll a 1 or a 2 at first level then you stuck with it.

The alternative is rolling two dice and adding the result to your hp, since it says roll two dice.

Quote from: Exploderwizard on March 19, 2024, 07:47:44 PM
The table itself dioes kind of hint at that being the case. A level 1 fighter has 1+1 HD. When 2nd level is reached and the new HD total is 2, if you didn't roll 2 dice what is the alternative?

I think the alternative is that you replace the +1 with the new hit die, which could also be a 1, but could also be higher than a 1.

Quote from: Domina on March 20, 2024, 12:29:36 AM
The alternative is rolling two dice and adding the result to your hp, since it says roll two dice.

This is incorrect and not an alternative.  The ways of interpreting it are:
You could subtract out the constant and then roll the new die.
You could reroll all your dice at every level and take that as your total.
A case is made for the method that was allegedly used at other tables, which is:
You could roll all your dice at every level and take that as your total if it is higher.

If you have 5 hit points and achieve level 2, you don't add two dice to the 5.  We know this because there's an example that precludes this possibility, and also, no rule tells us to do this.

For OD&D, the Greyhawk Supplement introduced d4 for magic users and d6 for clerics and d8 for fighters. That system allowed for one new HD added each level, so rolling one die and adding it to a previous total works well.

The problem is pre-Greyhawk OD&D, where HD go from 1+1 to 2 to 2+1 and so on, where sometimes you aren't adding a full die. Going from 2 to 2+1 is a no-brainer, but how to you go from 1+1 to 2? Add a new die and subtract one to account for the old +1? Not as smooth as the later system. Much easier to re-roll each level. (I never have HP go lower -- so a lucky high roll at one point may mean you go a few levels without improvement, but an unlucky low roll can be overcome with the next roll.)