Half-dragon + half-dragon: do they breed true?

[redking]

If a half-dragon human (for example) mates with another half-dragon human, do they breed true? Will the offspring also be half-dragon humans?

[shaikujin]

If a half-dragon human (for example) mates with another half-dragon human, do they breed true? Will the offspring also be half-dragon humans?

There are no rules support for this afaik.
The offspring will be a human. (Who will have to take the half dragon template, or not).

Lycanthropes have some support due to the existence of Natural Lycanthropes.

[Psyren]

You can't get a true dragon that way if that's what you're wondering. But you could get anything from another half-dragon, to a spellscale, to Silverbrow human etc. Possibly you could get a regular {insert humanoid} with some dragony traits or alternate racials.

[redking]

You can't get a true dragon that way if that's what you're wondering..

I am wondering if the offspring will be a human with the half dragon template.

[Xervous]

Rules wise I am not certain. All the flavor/setting color I can recall have half dragons interbreeding down to dragon blooded or other variants.

[Biffoniacus_Furiou]

This has been discussed previously, quite extensively.

Each parent contributes half of each chromosome pair. So each parent's chromosomes are 50% human and 50% dragon. For every individual chromosome, each parent has a 50% chance of contributing their dragon half, 50% chance of contributing their human half. For some chromosomes both parents will contribute their dragon half, for others both parents will contribute their human half, and others still can be 50/50 like their parents have.

So if those two human half-dragon parents have three children, one could be ~75% dragon, one could be ~25% dragon, and one could be 50% dragon like their parents. While extremely unlikely, they could actually produce a true dragon offspring, or a normal human offspring.

[redking]

Each parent contributes half of each chromosome pair. So each parent's chromosomes are 50% human and 50% dragon. For every individual chromosome, each parent has a 50% chance of contributing their dragon half, 50% chance of contributing their human half. For some chromosomes both parents will contribute their dragon half, for others both parents will contribute their human half, and others still can be 50/50 like their parents have.

I find this convincing.


So if those two human half-dragon parents have three children, one could be ~75% dragon, one could be ~25% dragon, and one could be 50% dragon like their parents. While extremely unlikely, they could actually produce a true dragon offspring, or a normal human offspring.

But the idea that a dragon could be produced, not so much. Maybe if the other half was an egg laying creature. I find it hard to believe that a mammal could spawn a dragon.

[liquidformat]

AFB but Half-Dragons do show up in Races of Dragon and Dragonimicon one of those books might talk more in-depth about breeding. Also there is third party book bloodlines and bastards which is a decent place to reference, though some of the rules in there may fly in the face of the half-dragon template rules...

Part of the issue in general though is you can gain the half-dragon template through magic rather than simply breeding since it is a template so that might cause some issues with half-dragon breeding...

[Biffoniacus_Furiou]

I find this convincing.

But the idea that a dragon could be produced, not so much. Maybe if the other half was an egg laying creature. I find it hard to believe that a mammal could spawn a dragon.

Like I said, it's extremely unlikely. Humans have 23 chromosome pairs, so for a 100% dragon to be produced you would need 46 consecutive 50/50 coin flips to all land on heads, the chances of which are roughly one in 70.37 trillion. You'd have the same chances of them producing a 100% human.

Granted dragons may not have the same number of chromosomes as humans, but due to their magical nature it simply works. If that's the case, the above 100% dragon chromosomes wouldn't be the right chromosome count to be a dragon. It likely wouldn't be viable at all, unless you hand-wave it with magic, or pretend chromosome count doesn't matter for dragons, or similar.

Regarding the egg comment, maybe it hatches out of the mother like a xenomorph?

[lord_khaine]

Initially i think its important to recall that we are dealing with an intense degree of magic here.
So step 1 is pushing the natural rules of genetics outside.

With them out of the way, we can instead look at what the usual behavior is in these cases.
And the general theme seems to be that the magic is generally diluted.
So yeah, im with Psyren on this one.


But you could get anything from another half-dragon, to a spellscale, to Silverbrow human etc. Possibly you could get a regular {insert humanoid} with some dragony traits or alternate racials.

[Batcathat]

But the idea that a dragon could be produced, not so much. Maybe if the other half was an egg laying creature. I find it hard to believe that a mammal could spawn a dragon.

This seems like an odd point to get hung up on considering the entire situation already depends on a mammal and a reptile (or whatever dragons count as) not only having children but fertile children with each other.

[Nifft]

If their children are true dragons, then obviously they did breed true.


But seriously, in most of my games I don't even have multiple species of dragon anymore. The population numbers which I prefer just don't support multiple species. Instead, I usually have dragons take their color from the environment or domain to which they attune themselves.

[liquidformat]

This seems like an odd point to get hung up on considering the entire situation already depends on a mammal and a reptile (or whatever dragons count as) not only having children but fertile children with each other.

Since when does it depend on a mamal and a dragon procreation? A creature can become a half-dragon through a ritual in no way requiring a dragon being present or doing the deed.

[Xervous]

If their children are true dragons, then obviously they did breed true.


But seriously, in most of my games I don't even have multiple species of dragon anymore. The population numbers which I prefer just don't support multiple species. Instead, I usually have dragons take their color from the environment or domain to which they attune themselves.

Out of curiosity what numbers, regional distribution and population densities do you usually work with? I remember some startling numbers coming out of allotting the traditional larger size domains that didn’t speak well for genetic diversity among the 10+ gummy flavors to say nothing of the mystery packages.

[Nifft]

Out of curiosity what numbers, regional distribution and population densities do you usually work with? I remember some startling numbers coming out of allotting the traditional larger size domains that didn’t speak well for genetic diversity among the 10+ gummy flavors to say nothing of the mystery packages.

I'm not hopeful about being able to dig up the exact numbers, it was a spreadsheet from several laptops ago...

Generally, what I came up with was a monster palette which allowed interbreeding for some hybrids -- like a griffon could breed with a lion or a giant eagle, and an owlbear could breed with a giant owl or bear -- and that change allowed a range of adventure-friendly monsters.

For Dragons, it was a tremendous caloric intake while the dragon was awake. I might have used bears for the baseline? Or tigers? Sorry, I mostly just remember my solution.

IIRC this same type of single-species dragon was used in Pillars of Eternity (a video game), and they came up with some pretty cool designs for the "unique" dragons which evolved by claiming a domain with a specific environmental aspect.

[Thurbane]

For the sake of simplicity in my game, I'd probably rule the offspring to be Humans with the Draconic Creature template, which represents a creature with some Dragon heritage, without being a full Half-Dragon.

[Xervous]

I'm not hopeful about being able to dig up the exact numbers, it was a spreadsheet from several laptops ago...

Generally, what I came up with was a monster palette which allowed interbreeding for some hybrids -- like a griffon could breed with a lion or a giant eagle, and an owlbear could breed with a giant owl or bear -- and that change allowed a range of adventure-friendly monsters.

For Dragons, it was a tremendous caloric intake while the dragon was awake. I might have used bears for the baseline? Or tigers? Sorry, I mostly just remember my solution.

IIRC this same type of single-species dragon was used in Pillars of Eternity (a video game), and they came up with some pretty cool designs for the "unique" dragons which evolved by claiming a domain with a specific environmental aspect.

I stumbled across an interesting assessment of Smaug that modeled him off of bird caloric consumption with most days spent resting. https://worldbuilding.stackexchange.com/questions/10098/what-is-the-approximate-caloric-intake-of-a-dragon
Granted that Smaug is utterly massive compared to the average D&D dragon I was surprised to see how small this estimate ended up at. This shifts the issue to a population size suitable for genetic diversity which strongly dissuades the Heinz 57 variety approach unless you’re in Monster Hunter land where literally every creature is half dragon.

[redking]

For the sake of simplicity in my game, I'd probably rule the offspring to be Humans with the Draconic Creature template, which represents a creature with some Dragon heritage, without being a full Half-Dragon.

This does make a lot of sense. I think I will go with this.

[Asmotherion]

I suppose.

For refeance, 5e half dragons are unable to breed save for magical means. But 3.Xe does not have this limitation, suggesting that two half dragons would produce a half dragon I suppose.

[Xervous]

Past a point I suspect you just end up with mongrelfolk.

[Remuko]

Id probably just roll 1d4. Full Human, Draconic Human, Half Dragon Human, and Full Dragon all being potential results.

[Nifft]

I stumbled across an interesting assessment of Smaug that modeled him off of bird caloric consumption with most days spent resting. https://worldbuilding.stackexchange.com/questions/10098/what-is-the-approximate-caloric-intake-of-a-dragon
Granted that Smaug is utterly massive compared to the average D&D dragon I was surprised to see how small this estimate ended up at. This shifts the issue to a population size suitable for genetic diversity which strongly dissuades the Heinz 57 variety approach unless you’re in Monster Hunter land where literally every creature is half dragon.

That's a more nuanced analysis than what I had crumbled together -- he's got leisure time lounging measured as well as active, while I just had active vs. hibernating.

[Promethean]

I stumbled across an interesting assessment of Smaug that modeled him off of bird caloric consumption with most days spent resting. https://worldbuilding.stackexchange.com/questions/10098/what-is-the-approximate-caloric-intake-of-a-dragon
Granted that Smaug is utterly massive compared to the average D&D dragon I was surprised to see how small this estimate ended up at. This shifts the issue to a population size suitable for genetic diversity which strongly dissuades the Heinz 57 variety approach unless you’re in Monster Hunter land where literally every creature is half dragon.

Granted, as messed up as D&D ecosystems are already, would a dragon slowly filling it's environment with half-dragons actually be surprising?