# A simple house rule for hit points

Here’s the rule for hit points that I’m using, it’s inspired by Stars Without Number:

Maximum hit points at level one and each time a character gains a level ALL hit dice are rolled and that value is used unless it’s less than the character’s old hit point total.

So for example a fighter would start with eight hit points and when they got to second level they’d roll 2d8 and take that result as long as it’s eight or higher.

The basic idea is to allow for the fun of random rolling without having an unlucky roll hamper a character permanently (for example a fighter rolling a 1 at first level for hit points). It also makes characters harder to kill at first level without giving any long term power boost.

Thoughts?

I’ve definitely thought about using a similar rule. It means you never get permanently shafted by a bad roll or two, and it also prevents a couple of good rolls from putting you far ahead permanently.

I use that rule in my campaigns.

Here are the house rules I use for hit points. Justification for these rules appears below.

All PCs, NPCs, and monsters get average hit points per Hit Die (1d4=2.5, 1d6=3.5, 1d8=4.5). Note that 0.5hp is more than 0hp, and you get the “at 0hp” bonus on the Mortal Wounds table if you are at -0.5 hp.

## All characters that have the Adventuring proficiency get maximum hit points for the Hit Die they receive at 1st level (1d4=4, 1d6=6, 1d8=8). Note that 0th level is not 1st level.

After dealing with opposed d20 rolls in 3rd and 4th edition for this last decade and change, I’ve come to the conclusion that having random elements on both sides of the equation is just two swingy for my tastes. I want the players to be making meaningful choices, and to do that they need to be have some meaningful, reliable data to base their choices on. This is the reason I love the ACKS stealth mechanics: the opposed Stealth skill vs Perception check was so unpredictable, my players just gave up trying sneak past anything. Coupling random hit points with random damage - or attack rolls vs. defense rolls in systems that use that kind of mechanics - introduces a similar situation in combat. Again, I’d rather the players be able to make a meaningful decision about whether or not to try to fight something.

With that in mind, I also introduced the following house rule:

## Sizing-up Opponents: Any character with the Adventuring proficiency can guesstimate how tough any creature or person he encounters is, and we model this by telling the player its HD or level.

These rules are all as yet untested, but I’m running my first ACKS session on Sunday, so we’ll see how it works pretty soon.

James C. Bennett wrote: All PCs, NPCs, and monsters get average hit points per Hit Die (1d4=2.5, 1d6=3.5, 1d8=4.5). Note that 0.5hp is more than 0hp, and you get the “at 0hp” bonus on the Mortal Wounds table if you are at -0.5 hp.
Note that this has exactly the same effect as saying average hit points, rounded up, except that rounding is simpler for players to remember.

1HD avg: 2.5 takes 2 damage, has 0.5 left; takes 1 more point of damage, has -0.5 and is treated as if at zero.
1HD rounded: 3 takes 2 damage, has 1 left; takes 1 more point of damage, has 0 and is treated as if at zero.

2HD avg: 5 hp.
2HD rounded: 5 hp.

Except for those players who will conveniently forget to recalculate from scratch, add 2.5 hp to their 3 from the previous HD, and round up to 6, compounded over 14 levels. I’d rather just deal with the fractions.

My gut reaction to this was that the discarding of lower-than-previous-level totals would give the dice a substantial bias to the upside and that by the time players got to high levels, they’d have a lot more hitpoints than if they’d used the rules as written.

So I did some analysis. I rolled hitpoints for 600,000 9th level fighters. (Boy, is my dice throwing hand tired. And my d8 is worn down to a nub!)

I limited it to 9th level, since after that the number of hitpoints added is a constant. I limited it to fighters because I didn’t want to complicate it with multiple dice types.

200,000 characters used option 1: The rules as written: d8 every level, cumulative, for 9 levels.

200,000 characters used option 2: The rules as written, except max hp at first level.

Finally, 200,000 used Option 3: The house rule described by OP in this thread.

Results:

Average of Option 1 over 200,000 characters: 40.5
Average of Option 2 over 200,000 characters: 44.0 (No surprise there.)
Average of Option 3 over 200,000 characters: 42.4 (Seriously!?)

I thought it must be a fluke, so I rolled another 600,000 characters and then another 600,000 after that. (After which, I rolled another 600,000.)

That’s 2.4 million characters rolled, and the averages for groups of 200,000 per option always came out to within .1 of the results above.

Since the expected values turn out to be almost identical, and since this method prevents people getting screwed for long and also keeps them from getting too much long term advantage from lucky rolls, I think I’m adopting it. (I might also give them a 2hp bonus at level 8 in order to even it out perfectly with Option 2.)

Thanks!
m

That’s pretty much what I expected but it’s good to see statistical confirmation of it. My thinking was that that upward bias would exist but that it wouldn’t be very persistent since if you (say) rolled awesome at fifth level and got (say) 35 HPs for a fighter that’d would be nice for a level or two but then it’d be overcome by just getting more hit dice so that even mediocre rolls would overcome the 35. At level 9 the house rule I proposed would only help you if you rolled really really well at 8th 7th level AND rolled poorly at 9th.

Or to be less wordy, it basically cuts the long tail of really really crappy hit point rolls to the left side of the bell curse without affecting the rest of the bell curve too much.

I’d love to see a graph of the bell curve that each option gets. Options 1 and 2 will be the same of course (option 2 just shifted right by a few points) but I’m curious how much tighter option 3 gets.

Why not just round high and call it a day? d4=3, d6=4, d8=5. Max at first level and go from there? Much simpler.

Ask, and ye shall receive:
http://www.thegattens.com/images/HP-Analysis.jpg

Because (a) that adds up to 6.5 extra hp, which is enough to survive two extra average sword blows, which is more generous than I feel I need to be, expecially given that (b) my players have known about this rule change for a couple of months, and not one of them has questioned it. But, if they end up revolting against it after we play on Sunday, I’ll probably go with your suggestion, rather than my original plan of reverting to the 3rd Ed average hp rule of “d6=3hp at even levels and 4hp at odd levels” that everyone is used to.

I always loved this hr (it’s from way back in time)

Note that the reason why option 3 ends up lower than option 2 is because you’re re-rolling the first-level die instead of keeping it maxed.

To illustrate, the average second level guy rolling 2d8 is going to end up with 9 hp, only 1 more than he had at first! As such, if you were going to going to give them the 2 hp bonus, I might start it at level 2 (where option 2 is giving the average guy 12.5 hp).

This is how I do it too. The players like it, those who get bad rolls aren’t too messed over. Now one guy was getting crazy lucky for a while and ended up just two off maximum at 5th level - rolled 4 8’s and a 6 for his Fighter. Now that was a stout fellow. But the next two levels saw no increase and others catch up.

One thing I do allow is at higher levels (past 9th) the continued reroll of the 9dx. It seldom matters but on a few occasions the higher level characters inch a little closer toward maximum HP.

Another benefit is that it makes handling level drains much easier. No more tracking hit points rolled at each level. I’d rule that re-rolling HP when level-drained must result in a total at least one less than the initial HP value. So, if your character was 7th level with 30 HP and was level-drained down to 6th level, when they re-roll their hit points, they cannot have HP greater than 29.

Another benefit is that it makes handling level drains much easier. No more tracking hit points rolled at each level. I'd rule that re-rolling HP when level-drained must result in a total at least one less than the initial HP value. So, if your character was 7th level with 30 HP and was level-drained down to 6th level, when they re-roll their hit points, they cannot have HP greater than 29.

If you think about the probabilities, that’s still quite evil - rolling max(1d6,2d6,3d6,4d6,5d6,6d6) probably left them far stronger at 6th level than just rolling 6d6.

Another way to mitigate the swinginess of the linear HP roll, is to roll 3dX (X = hit die) and pick the middle result. This creates a nice bell-curve with the same upper and lower limits.

Thusly, when a Fighter goes up a level, he’d roll 3d8 (1,6,7) = 6 HP’s
A roll of (1,1,8) = 1HP and a roll of (1,8,8) = 8HP’s

I'm going with max hp at first level, then 1/2HD every level thereafter.

I'm also using my own houseruling on conditions, based on your hit points. The first half of your hitpoints represent brusing, minor fatigue, minor cuts and grazes. Drop into the second half (Bloodied) and you're into major fatigue, heavier brusing, more serious cuts, muscle pulls and so on, which give a -1 to hit, Proficiencies and saves and movement reduced by 30'.

Hit zero (or up to negative your Constitution score) and you're in danger of going unconscious, having to make a Fort (Poison and Death) save every round to stay with it. Even then you're at a -2 to hit, Proficiencies and saves, and movement reduced by 60'. Go below negative your Constitution and you're automatically unconscious (and we get into Mortal Wounds).

I didn’t know this rule was in there. I have been using this sort of house rule for over a year now. It works well and the players all like it. And it does eventually work toward giving them above average hit points, but that is later in the game most of the time and by that point everyone has a real affinity to their character, so I am okay with that HP bias.