How would parents’ ability scores affect their offspring?

Question

Problem and Question

In my campaigns, sex is an integrated part of the game experience, and as such, the joys and/or problems that may come from that are part of the game. Last session one of my players’ characters gave birth and got a daughter, and as I've previously done (a few years since it happened the last time), she gets to roll stats for the child which are then modified by a child template.

This time around, however, I’d like for my player to get to further modify the child's stats by inherited biology, ɔ: by the father’s and mother’s ability scores. Are there any rules published anywhere addressing this in D&D (3.5e)? If none exist, empirical knowledge and experiences on house-ruling such adjustments, would give valuable insights.

Notes

1: If not for D&D, then solutions from other 3d6 ability-based games could be of interest.

Answer 1

While there don't appear to be official rules, an answer to How to determine PC genetics in D&D for the purpose of creating 2nd generation PC's details a method of determining the ability scores of an offspring based on their parent's.

Answer 2

I think you misunderstand what ability scores represent.

Humans, to say nothing other creatures, have a wide array of diverse aptitudes. The degree to which any one of these is heritable is difficult to discern, and not well-supported (or well-denied, to be fair) by science. Tons and tons of research have gone into these questions, and have basically managed to come up with a muddled mess that does not clearly confirm any conclusion. A lot of it seems to come down to semantic arguments about how to define and measure whatever particular aptitude you are interested in.

That’s real life. In D&D, we have just six ability scores, rather than the myriad things a person could be naturally suited or unsuited for. A person in D&D is just strong, not strong in some ways but not others. Likewise for each of the other ability scores. These are abstractions, an attempt to fudge all these different aptitudes through a streamlined numerical process that is workable for a game. Abstractions are crucial to having a game that is actually playable, and the choices one makes in the abstractions for a game determine a lot about what sort of game it is.

D&D’s six ability scores, then, is a very high degree of abstraction. Each of the six ability scores is covering infinite different fields of endeavor that one might have natural aptitude for. Remember the state of the art with respect to the heritability of these kinds of traits? A muddled mess, I called it. Lots of semantic arguments about definitions and the appropriateness of various measures. The D&D ability scores have to cover all of those definitions and measures. Those arguments are abstracted away entirely.

Which means that each ability score is rather schizophrenic¹ about what it actually represents. It might represent something highly heritable while at the same time representing something that has absolutely nothing to do with genetics and cannot be inherited at all (particularly with the mental ability scores).

On top of this, the typical array of ability scores for NPCs in 3.5 is 11, 11, 11, 10, 10, 10. The thing the average person is best at is only 1 higher than the thing they’re worst at! In other words, ability scores are massively disconnected from our everyday life, where there is great variety. All that variety is stuck in just 1 ability score point. Differences larger than these are extremes rarely if ever found in real life. That means that no matter what we do, we are already dealing with something that is outside the realm of our real-life intuition here.

To go further, even the elite array has a highest score of 15 and lowest of 8. PCs can go to 18, but it’s better to ignore them for this—PCs are not remotely realistic² and we have absolutely no metric for saying that special something that makes someone a PC is heritable or not. So that 15 represents the height of regular human endeavor,³ and 8 represents the regular nadir. But these scores are exceptional, ability scores that might have someone labeled “freak” and so on. These are only more outside our intuition and understanding of real life, even as limited as that is.

So I would have a child determine his or her scores exactly the same way everyone else does, without any special reference to his or her parents’ ability scores. If the child has similar scores, maybe those were inherited—after all, the ability scores can represent traits that may be genetic. Or maybe they were just the result of being raised by those parents. And if the child is particularly different, maybe that’s because ability scores also can represent things that aren’t inherited at all, and so of course the child would be unique.

For personal experience, I have certainly had many characters across many campaigns who were the children of other characters. Some of them had similar ability scores; others did not. I have never had any difficulty or problem describing this, and have never felt any need to use anything more. Per the above, I actually think that doing so would misrepresent reality more than not.

1. _{Used colloquially, to mean having many identities and being pulled in many directions; my psychologist wife might never forgive me. The actual disorder schizophrenia has almost nothing to do with the colloquial usage.}

2. _{My favorite illustration of this: a 1st-level human barbarian can out-run the world-record sprint speed, but maintain that speed for minutes at a time, and do it while wielding a battleaxe, wearing chain, and carrying 50-odd pounds of gear besides. And when his endurance finally runs out, he isn’t even fatigued—he just can’t run for a minute, and after that he’s totally fine.}

3. _{I am intentionally not attempting to actualize ability scores by comparing what a given score lets you do (e.g. maximum lift weight for Strength) or is said to be (e.g. the sometimes claim that Int×10 = IQ), since this falls in the trap of trying to treat the ability scores as exactly one thing when, as established, they each cover many, many things.}

Answer 3

I'm not aware of any rules for this - Pathfinder has rules governing the creation of child characters in general, but nothing about picking up hereditary traits as far as I can tell.

In any case, there's a good chance I wouldn't use those rules if they were available, because I think the most important question is how the child character will be used.

The child is fluff

If you don't expect the child to have any direct effect on gameplay and the stats are simply to make the child feel more "real" to the player, you have a lot of freedom. You could standard racial adjustments with others of equivalent power that better match the parents, or you could even let the player define the child herself using a point-buy system - after all, she's going to be there to teach the child and shape her development.

The child will remain an NPC

I'd replace the standard racial adjustments like I suggested above. It's worth noting that there's probably no rush here - just because she rolls an 18 Str doesn't mean the baby can start wielding a greatsword on her first day out of the womb. I'd probably give the child standard NPC stats modified for age for at least the first 5 years or so, then gradually grow into the stats that were rolled - it seems reasonable to say that the gameplay effects of having an 18 Int rather than a 10 Int don't kick in until at least that point, if not puberty.

The child is a future PC

I've heard of multi-generational games where players wind up playing as the descendants of previous characters (usually because the previous generation of heroes was killed before they could stop the BBEG's plan, so the action skips ahead 20 years to the children of the PCs, now grown up and leading the rebellion against the BBEG). In that case, I would try to avoid defining their stats until they become a PC so as not to lock the player into a specific class. There's a good chance the child won't be used as a PC for real-life years, if ever, and I wouldn't want to be in the position of telling a player, "Sorry, I know you wanted to play a Fighter this time, but we rolled the stats for this character three years ago and we're stuck with them." The potential upsides don't seem worth it.

That said, you could always just ignore the previous stats in that case if you like - people change a lot as they mature, and it's easy to hand-wave the old stats as being "one possible future" or some such.