A character's Constitution score is the lowest a character's maximum hit points can be.
Changes & Examples
A character's Constitution modifier is no longer applied to the hit points a character gains each level. The character's Constitution score, instead, sets the minimum threshold for the character's maximum hit points.
Example: A 2nd level fighter in B/X, for example, with a 15 Constitution would not have a maximum of 2d8+2 hit points but, instead, would have rolled only 2d8 for her maximum hit points. No bonuses or modifiers applied.
If the rolled hit points were lower than the fighter's Constitution score, she would take the 15 Constitution as her max hit point total instead of what she rolled with her hit dice.
What is this?
This house rule is a lot simpler than it seems from the description above. I tried to make it easy to understand but, even reading it, it seems a lot weirder on the page than it is in practice.
In pretty much all editions of vanilla D&D, when a character increases their hit points they modify that increase by their Constitution (or CON) ability score bonus. A fifth edition
thief rogue with an 8 CON (a.k.a. -1 CON bonus) would get 1d8-1 added to his maximum hit points each level.
This house rule removes the CON bonus from leveling. A character's CON score is just the lowest a character's maximum hit points can be unless they roll hit dice above that score at some point.
Another example: A 2nd level fighter in first edition with a 13 CON may roll an 11 on 2d10 after gaining 2nd level. This fighter's maximum hit points would remain 13, as it started for the fighter at 1st level. But perhaps the fighter rolls an 18 on 3d10 at 3rd level. Then the fighter's CON score is no longer applicable and the fighter's maximum hit points are set to 18.
What's the point?
I started using this house rule to solve two problems: survivability at low levels and hit point inflation. These problems are related, in that most efforts to improve survivability at low levels wind up making hit point inflation at higher levels worse. But hit point inflation is, by far, the more impactful of the two issues.
The more hit points the characters have, the more hit points the monsters need to remain a challenge. We have seen this upwards scaling since first edition but it has turned a corner in later editions where even low level adversaries can have 30 or 50 hit points.
But, at the same time, low hit points impede a group's ability to enjoy a night's adventure – as anyone who has had the good fortune of starting a game at 1st level with a fighter with 2 hit points can attest. You're just not going that far into the Cave of the Unknown (whether you want to or not) with 2 hp!
What this house rule did for me was turn that problem on its head.
How can we prevent a bump in survivability at lower levels, which is needed and justified in most editions, from resulting in characters at high levels who are able to fling themselves off of skyscrapers and still survive?
After a decent amount of system archaeology, I arrived at a culprit hidden in plain sight since the white box edition.
CON bonus: D&D's Fredo
In the game's earliest versions, adding the CON bonus to hit points at each level was less of a big deal.
- First, hit dice were lower across-the-board. A fighting man had a d8 hit die. A magic user had a d4. A cleric had a d6.
- Second, ability score bonuses were scaled-back. They went from -1 to +1 and that was it. First edition added more of a scale by going from -3 to +3. Then third edition and beyond took this further by making even a +5 bonus attainable for many starting characters!
This gave the vestigial "CON bonus to all hit dice" an outsized influence on gameplay. Given two B/X fighters at 6th level, rolling down-the-line average on hit points each level, and with their only difference being a 12 CON (+0 bonus) and a 18 CON (+3 bonus and a very lucky roll), the former would have 27 hp and the latter would have 45 hp. At 8th level, the lower CON fighter would have 36 hp and his comrade would have 60 hp. Almost twice as many hit points. This gets more pronounced as levels increase. Note that in B/X a straight-up dragon has around 42 hp.
As editions move forward, this has become worse and worse. In the early days, a +1 CON bonus wasn't a game changer and it was the best you could hope for. The difference today, however, is between a +5 and a +1. Those same fighters in the latest edition with a d10 hit die would have 38 and 62 hp, respectively, at 6th level and 49 and 81 at 8th level.
I think the reason this isn't considered a problem more widely is because it's always sort of been this way. But a five-fold increase in the impact of adding the CON bonus to hit dice at every level is a pretty big evolution, even if it has made its hide in shadows roll for going on 40 years.
Two Stirges, One Stone
The world's most popular fantasy roleplaying game has a problem in nearly all editions on both the low end and the high end. Even the fifth edition, with its focus on prolonging the "sweet spot" of the 3rd-5th level experience of previous editions, hits this problem on the high end.
The problem on the low end is survivability. A character with only a couple of hit points can be scratched to death by a house cat. This is a feature, not a bug, in Mork Borg. But in most other games it inspires groups to start at 2nd or 3rd level or give max hit points at 1st level or any number of tweaks and house rules to allow characters a chance at surviving that nasty housecat guarding the Tomb of Unholy Furballs.
The problem is almost all of these solutions make things worse on the other end. I've had a character avoid a TPK (total party kill) in a game by opting to jump off a cliff, knowing full well that the odds of 12d6 damage from a 120 ft. fall killing him were dramatically lower than facing a dragon by myself. My character was a 6th level, 2nd edition barbarian at the time with 52 hit points and a better-than-average CON score. My character jumped off a cliff, landed on his feet, and walked away. At 6th level. In second edition. 🤔
Running my own games, I've seen high level characters (6th level and above) take fireball damage for no reason, walk through traps with impunity, and demonstrate a near godlike disregard for incoming damage. It's like martial characters in most editions reach a sort of Luke Cage or Wolverine level at some point.
This house rule corrects the problems on both ends. A high CON character is more survivable at 1st level than a 2nd or 3rd level character in rules-as-written. High level characters reach a point where they no longer benefit from this survivability bump. And rolling unmodified hit dice (or allowing players to take the average if they need to) keeps characters on more of an even playing field with each other and the monsters in that edition (barring of course third edition and later).
Side Effects: Good & Bad
- Hit points are more homogenous. They are more limited in range and less swingy among party members. I prefer characters re-rolling hit dice every downtime (a house rule for another day) but, if that is not your jam, Bob the Fighter and Celeste the Ranger are going to have a more constrained range of hp at higher levels. Celeste may even have more hp than Bob at some point. Note this harkens back to the earliest editions too where CON bonuses never exceeded +1 and the highest hit die was a d8.
- Constitution damage is easier and less impactful. In all known editions, taking CON damage can involve a chunk of bookkeeping. If your character's CON bonus drops, you have to lower your character's max hp by some amount (which may vary if the DM has their own set of survivability boosts) and then potentially lower current hp if it exceeds the new maximum. It's not as bad as level drain (where you do all that and strip away spells and class abilities). But it's also something I've frequently seen players struggle with. The house rule here is a lot easier than managing CON bonus reductions. The new CON score (temporary or permanent) becomes the new lowest number for the character's max hit points. The problem is that traditional CON damage no longer matters after a certain point. The fix is to have any damage to CON also lower maximum hit points by the same amount, even if max hit points are higher than the current CON score. Your mileage may vary, of course. Your table may be good with CON loss just being a game trail to zero CON and death. No judgements.
- The CON bonus is left out in the cold. What do we do with the CON bonus now though? While previously right up there with Strength and Dexterity in the top tier of ability score bonuses of all editions, this change puts the CON bonus, well, nowhere. That's not a problem, however, as we can find new ways to get creative with this bonus. Perhaps adding CON bonus to saves against poisons (in earlier editions) or having the bonus itself set the minimum value a character can roll on a hit die when rolling hit points (in later editions). This inserts the CON bonus back into the picture squarely alongside Wisdom in that second tier of ability score bonuses.
- Later editions. Later editions (third, fourth, and fifth) assume that characters have lots of hit points. I'm not sure I would use this house rule in fourth or fifth edition unless I was going for a grittier type of game. The assumption that hit points are going to be inflated is baked in to the design of later editions. So much so that a character with a 6 CON is nearly impossible to create and hardly worth playing. If I were to give this rule a try in later editions, however, I would dramatically reduce the monsters' hit points – cutting them by a third or up to a half. The downside here is that overall this house rule would make higher level characters more "at risk" and would have virtually no effect on low level characters in many cases. In other words, it slightly curtails the problem of hit point inflation at higher levels but doesn't do much on the lower end with survivability because these later editions (fourth and fifth to be exact) already do a lot to mitigate that. An unexpected upside is that lowering monster hit points (and by extension higher level character hit points) would speed up combat a fair clip – which seems to be something a few folks are interested in.
Thanks for reading. It's been a while since I posted and I hope you all have found something interesting here. This is kind of been where my head is at lately. Hopefully, I can share more of these little tweaks in the future.