Assuming that in a setting, souls are made of energy and that the laws of thermodynamics still apply...

They aren't. There are a large number of pre existing souls who are waiting for their chance to come down and inhabit a mortal body. When the soul enters the body it forgets it's time prior to entering said mortal body. Souls come down and take bodies voluntarily, because it's a way to earn a better place in the cosmos after they die and return assuming they do well, but it's a risk because you may screw up royally and end up in a worse place. If you screw up eventually you can try again, but when you "reincarnate" as it were you tend to get a crappier hand then you would have otherwise. There are tons of spirits, an order of magnitude more than there are people on the earth at any given time. Hows that sempai.

Their made from the soul energy derived from the food the mother ate/absorbed from the environment.

>the laws of thermodynamics still apply
The god of fertility is also the trickster god and cheats the law all the damn time.

Yeah the universe isn't expanding the stars are just getting smaller.

they wont

after passing a certain line of living population number, the newborn are all weird, soulless things and only the deaths of a bunch of people could "create" new souls.

that's actually a pretty interresting campaign setting, with some people being born with a soul and therefore having some kind of intellectual ability that soulless ones dont have.

In the forge of souls duh, Every kid knows that. There the soulsmith hammers energy he gathers into souls.

The Gods of Life and Death have an energy budget for all new souls until the End of Times.

That's only the case for Avatars in Hinduism OR the case for Llamas in Tibetan Buddhism, no both I think.
And why Hinduism or Buddhism should be true in all fantasy settings with reincarnation ?

Well obviously it's either reincarnation or a limited supply.

Like Pillars of Eternity?

A large preexisting reservoir of soul-energy exists on some higher plane. Large, but still finite. The world is slated to end well before it runs dry.

Souls are like sticky taffy, as we grow and age, we collect ambient energy and it "sticks" to the outside layer of the soul. After enough years (the same amount of years it takes to reach puberty in humans) there are enough layers on the soul that both the father (during the act of conception) and the mother (gradually during gestation) shed off multiple layers of their soul and this combines, to create the nucleus of the new soul.

yes, this! puts a new spin on zombies!

i wonder, would people want to have sex less because they knew that making babies without spare souls would create horrifying, gormless mounds of flesh (thus creating a prudish, bitter culture) or would a society become even more violent, with murder and war being more common with people understanding that death must happen often so that real people could be born.

>tfw you realize that humans are the ones lacking souls and elves are what humans should be when born with souls...

I think it would make frequent wars more likely. If you want to certain that your kid has a soul, you gotta make sure a thing or two dies first. Killing those guys over there en masse becomes an appealing choice.

mom's sugar reserve. It grows slowly, causes vomits and dizziness. Your're welcome.

>There are tons of spirits, an order of magnitude more than there are people on the earth at any given time. Hows that sempai.
Thats fine for now, but what about the future when we reach that figure? It was only abour 300 years ago that the human population was an order of magnitude less.

Will fertility essentially crash as it has to match the death rate as there are 0 loose spirits at any one time?

Alan Kardec called....

Or his current incarnation anyway.

He wants you to know he exist(ed).

>would people want to have sex less because they knew that making babies
As reliable contraception is now generally readily available the link between sex and pregnancy is going to diminish. People will still have sex for fun, deciding to have children probably would become a rarer thing though yeah.

I mean the child is usually half of the mother and half of the father, so doesn't that mean it takes a chunk of soul from each party?

The child doesn't really develop a conciousness until later on in its' life, so it wouldn't need much. Over time that void could be filled through residual soul energy in the air, like condensation.

As for the parents, they're probably used to having their souls hacked to pieces at this point, so they don't feel a thing unless they have 3 or more kids within a short time frame. Then they feel like they're slowly dying, which they're wrong about. They're quickly dying.

So having kids kills your hopes and dreams? Sounds about right.

Mother's food like in real life? I don't understand the problem.

The same place all energy comes from: the sun.

If this is D&D, please play the adventure with Ashreadorn, the Dragon, starting with Nightfang spire, events which are canon and lead to Ashradorn becoming a Vestige for Binder usage.

That, and the ban on the unborn.

What about sperm and eggs? Perhaps each one contain little chunks of soul. Would explain why succubi want the dick so badly

That's only half true.

See, you only need one sperm to fertilize an egg; thus, when that connection is made, and the egg is fertilized, only then does soul pour into it. Though, since souls are non-solid and attached to their host, the rest of what was not used can flow quite easily back to the male.

Now with succubi, they mime this same act of zygote formation, except they don't stop at one single sperm cell; indeed they attempt to absorb all of it, and since the man's body does not understand what's happening, it pours each chunk of soul it can muster into the demon, hence why the man thereafter seems a lot less... present than when he started.

I like it. Lets crank it to 11 on the dial.
After sitting around waiting in a neather plane waiting for bodies for millennia. All those souls go crazy. A few of the (not so crazy/cazy like a fox) spirits manage to get a group effort together and tear into the mortal plane. Suddenly the flood gates open and countless spirits driven mad come flooding in. Most aren't powerful to push souls out of bodies and take them. When they cant get in they try to claw their way in and rip people to shreds. God of life and the god of death flip their shit and try to put a cap on it by no longer sending souls period. Most newborns end up stillborn or just feral without intellect. Of course if you had a skilled healer or magic user you could put energy into a baby and pretty much make it a homunculus with a (fake) soul.

If souls are pure energy, then they could be condensed into matter. You could build a fortress out of a countless number of souls.

God already made all the souls when He created the world, and has just been doling them out ever since. Once they're all used up, the heat death of the universe will occur.

I have this in my setting, except you just can't get pregnant without spare souls. Space and resources are not a problem, souls are the limiting factor of population. The best way to expand your empire is to take your army and raze your neighbors, then send your army home to their husbands and wives.

A cycle of reincarnation where souls are made of a core layer that is always whole and indestructable and an outer layer that houses the memories and expiriences of a life that can be swept away and separated during death, sometimes it doesn't happen and someone maintains memories of their past life.

Is a soul an elementary particle? Or is it a pattern or arrangement of particles? If the latter, it can be destroyed without violating any physical principles, just as you could destroy a chair. Maybe its pieces can't be completely annihilated, but after a certain point it ceases to qualify as a chair.

Makes genociding enemy populations now a goal so they take up less souls so your guys can expand.

>

Conception creates a new soul out of friction energy. This energy is released upon death in the form of an explosion.

There is no longer any need for graveyards.

Ask literally any atheist since this is our universe if materialistic existentialism is correct.

lets crank it up to 11 AGAIN!
what if all that psychic energy sitting around waiting for humans to develop is why humans are fundamentally insane to begin with? what if that is the original sin of this universe?

They aren't created. Energy is merely transferred from one form to another.
Increasing birth rates will actually pull energy from elsewhere. If you have too many kids, the stars may start to go oit.

>llama reincarnation

That's why pregnant women eat weird shit.
Like zap bug's maggots, clay and grass from graveyards. It's all transmuted into a new soul with vaginal magic.