Aging for the (half) ageless

[Thatdumbdm]

So I'm running a game where significant in game time may pass between adventures and I've run into a slight snag. I was reviewing the rules for ageing so I could make sure that my players applied the penalties and buffs correctly and couldn't find any rules on what to do for half breeds. The life span of half elves seems to suggest that all you need to do is split the difference. Now that's all well and good and that's a simple enough solution that I think I'll run with it but then I came up against the fact that one of my players is a half celestial and another a half fire elemental and a third is a half vampire. That leaves my simple rule at half of forever as an age limit:/ anyone have any advise on the subject? Any rules they can find or any general advise on what you all would do would be helpful.

[Kelb_Panthera]

Double the mortal parent's lifespan or no aging?

[Thatdumbdm]

Perhaps double the mortal parents age category length but no max lifespan?
Edit: that seems like a fair median between those two options. That way they age but the immortality of their immortal parent keeps them from dieing?

[Kelb_Panthera]

Perhaps double the mortal parents age category length but no max lifespan?
Edit: that seems like a fair median between those two options. That way they age but the immortality of their immortal parent keeps them from dieing?

That's actually more horrifying than the fate of the liger; a creature who's cross-bred nature leads them to just keep growing until their body collapses under its own weight.

... I approve

[Thatdumbdm]

Alright I'll roll with that one then. Thanks for the help kelb:) oh quick question I've been meaning to ask you: does the link in you signature not work or am I just having trouble with it for some reason?

[Kelb_Panthera]

Alright I'll roll with that one then. Thanks for the help kelb:) oh quick question I've been meaning to ask you: does the link in you signature not work or am I just having trouble with it for some reason?

Seems to be broken. Thanks for the heads up.

Wait. Worked after all. Just took a few seconds.

[Thatdumbdm]

it doesn't appear to be working on my mobile devises but i got it to work on my computer. thanks again for the help

[ShurikVch]

Half-Celestial, Half-Elemental, and Half-Vampire aren't races, but templates
Template change whatever it says it change - and nothing more
For example, this thing about the Shade template (Races of Faerûn):

Shades have extraordinarily long lifespans. By trading some portion of their souls for the stuff of shadow, they extend their lifespans tenfold. Shades created from humans use the following aging effect characteristics instead of the ones in Table 6-5 in the Player's Handbook:
Shade (human) 300 450 600 +6d% years

Unless templates in question say something like this, they have no impact on longevity
Say, Dragons have very long lifespans, but Half-Dragon Mayfly still die at the end of the day

[Flickerdart]

A star that burns twice as bright, burns half as long. To provide an in-setting justification for the rules Shurik quotes, you can say that even though one parent creature is immortal, the toll of being half-X takes on mortal biology offsets that immortality.

Of course, you could also say that this only makes sense for creatures that remain mortal, such as half-dragons (dragon type) or half-vampires (type unchanged). A half-celestial becomes an Outsider, but not a Native one, so they should be immortal.

[Inevitability]

For what it's worth, in 5e half-dragons live about twice as long as the base creature.

[ShurikVch]

A half-celestial becomes an Outsider, but not a Native one, so they should be immortal.

Half-Elementals are Outsiders too. Does it mean they are also immortal?

[MaxiDuRaritry]

Half-Elementals are Outsiders too. Does it mean they are also immortal?

Shouldn't they be, I dunno, elementals?

[Flickerdart]

Half-Elementals are Outsiders too. Does it mean they are also immortal?

Sure, unless otherwise specified.

Shouldn't they be, I dunno, elementals?

You'd think so, but no! The template says: "Because the half-air elemental is still mostly flesh, it cannot be of the elemental type. Instead, the creature's type changes to outsider."

[Inevitability]

Shouldn't they be, I dunno, elementals?

Not really. I believe the general 'elemental' ancestor to a half-elemental is assumed to be a genie, which is an outsider itself.