Devils and Demons

[Kavok]

A few questions regarding these planar races.

1. Do angels, devils, and demons sexually reproduce with one another? I know tieflings exist, but I haven't seen any material that mentions devil/angel/demon young.

2. How are new angels/devils/demons created if not sexually? When mortals die does the god they worshiped 'transform' them into something else if he/she wishes?

3. How probable is it that the demon/devil side of a tiefling parentage would be the female side? (IE Female demon + human male? ).

 

[kreynolds]

Honestly, you have a lot of breathing room with a topic like this, so feel free to do what best fits your game, but...

1. Do angels, devils, and demons sexually reproduce with one another? I know tieflings exist, but I haven't seen any material that mentions devil/angel/demon young.

Various books cover this. In particular, the Fiendish Codex books do. Hordes of the Abyss said most demons are spawned directly from the chaos of the abyss, so the population of demons in the abyss, as we know it, is not largely due to sexual reproduction. Demons with the ability to shapeshift/polymorph, in particular, can produce offspring sexually. It says that demons with the necessary "equipment" typically have sex only to produce half-fiends, so there you go.

2. How are new angels/devils/demons created if not sexually? When mortals die does the god they worshiped 'transform' them into something else if he/she wishes?

I have seen mention of gods transforming their faithful champions into planar beings, but I cannot remember where I saw that.

3. How probable is it that the demon/devil side of a tiefling parentage would be the female side? (IE Female demon + human male? ).

Very possible. If a succubus takes on the form of a human female, she can most certainly produce a child with a human male. This kind of case is not covered in great detail by any WotC books that I know of, but more than a few third-party supplements have done so.

 

[Squeaky Bill]

I handle a race's origins in my world's cosmology. Consider what plots you want to use, the myths you use for inspiration, and the key forces that drive the monsters' actions.

It might be helpful to create a personality for a representative NPC for a monster type. Then you can decide what sort of biology and society spawned it.

Try to favor origin stories are open ended and that freely explain secondary elements in the monster's description. Try to avoid origin stories that restrict your plot options and feel contrived.

 

[Hedgemage]

I can't remember exact references, but Fiendish Codex II explains how the creation and promotion of devils is strictly controlled as part of the infernal hierarchy. That being said, Asmodius and one of his Dukes each have a daughter that rules a level of the Pit, so at least these unique beings can reproduce. I would imagine that reproduction has rules in the very organized layers of hell regarding who can and can't.

Since the Abyss is either infinite or composed of 666 infinitely large layers (depending on how old school you are) there's plenty of room for demons of all kinds to breed, spawn, spore, or whatever they do.