How can I discourage parents from exploiting celestial events?

Question

The moon has an effect on the mana content of an individual. During high tides, a person's mana increases and becomes more powerful. This is the time in which more powerful spells can usually be performed, as a person's power reaches its crescendo. During low tides, mana decreases. However, the times in which your mana reaches its highest or lowest point are dependent on the celestial alignment at the moment of your birth. Low tides are linked specifically to the individual, and occur when the exact celestial alignment occurs again. Due to this fact, the times of increases and decreases of mana will vary from witch to witch.

The exception to this are those born during a solar eclipse. These individuals never experience low tides, and are born with significantly higher mana content than other children. Witches born during this period enjoy a constant balance of high mana compared to their compatriots, who must deal with their mana going up and down consistently. Knowing humans, many parents would obviously prefer that their kids would be born around this time. Mothers would take steps to give their offspring any advantage they could in life. As predicting eclipses are easy, witches would go out of their way to plan ahead when children are conceived, in order to align their birth with a solar event.

I would like to prevent a mad dash to have kids around this time, as these kids should be considered lucky rather than planned out. Witches should be discouraged from taking advantage of the cosmology. Is there any way to prevent this?

Answer 1

Not possible as suggested. People will game the system.

When it comes to pregnancy and childbirth, there are many a danger to both mothers and children. Yet that hasn't stopped people trying to "game" it and try to get something more out of it for millennia.

Other answers suggest some sort of rationality from people at large yet even in our world we have had parents try to get benefit from their progeny. Sometimes it's real, like The Great Stork Derby from the early 20th century but that's one of the few cases where the parents had a tangible benefit in front of them.

There are many folk beliefs and practices that have no basis in reality whatsoever, yet mothers subject themselves and their unborn for supposed benefit:

• some milder variants are just fortune reading or horoscopes. They don't require anything from the parent and child and are shown to be completely unreliable. Yet the practice continues to this day and is quite popular. In some (admittedly rare) cases, a potential parent will try to "influence" the fate of their child by trying to bring it on a specific date, so perhaps they would be born under a different sign or otherwise will get a different fortune reading.
• speaking of trying to bring children on specific times - there have been a lot of cases of this over the years. It doesn't have to be tied to fortune reading - some parents would try to bring their children on a specific holiday (so, the child might be blessed or protected in some way) or perhaps avoid some supposedly bad days (when it would be cursed in some way). And there are many other reasons to assign special meaning to a birth date. Again, there is nothing tangible or real behind this yet parents have been trying to force a birth despite this.
• some folk beliefs aren't that much about the birth itself but might assign special meaning to actions the mother does during the pregnancy. These include practices supposed to grant the child some benefit (beauty, strength, intelligence, courage, luck, etc.) or avoid some potential harm (laziness, cowardice, stupidity, ugliness, misfortune, etc.). Yet again, there is no actual link between the practice and the supposed quality it would give or avoid, yet parents have and do practice these. So milder variations might have the mother do or avoid doing something that's ultimately of no consequence. But some practices might involve the mother imbibe poisonous, toxic, or otherwise dangerous substances. Or even harm herself and/or the baby physically. Some of the practices are not very pretty and luckily are mostly left in the past, yet even today there are home made pregnancy tests and even tests for the sex of the baby...
• ...home made anything related to pregnancy has the potential to be harmful. These home made recipes are still widely practised today but have their roots in ages past. Most of these have reliability less than 50% - pregnancy tests, tests for the sex of the baby, recipes that are supposed to help the mother or the child, recipes supposed to protect, etc. The sort of common thing between them is that they require mostly everyday stuff. Maybe bleach which can be highly dangerous, maybe some salt which isn't. Some foods might be preferred or avoided which, at best, has no relevance, but might deprive the mother and/or child of valuable nutrients.

So, for ages people have tried to influence the pregnancy and birth to result in some benefit, even when they can't or actually harm the mother and/or child. If there is any real benefit to be had, they'd intensify their efforts.

At the very least, you can expect more pregnancies and births. So, perhaps you can see a lot of polygyny relationships where one man has many women as spouses, so if at least one gives birth to a child at the right time, the whole family benefits. If we take this a step further, it could be applied to a whole community - if at least one child in the village is born at the right time, it would be of great boon to the whole village, as their protector. So, the village can only benefit of many pregnancies.

This...could turn dark. So here is the thing - pregnancy and birth are a potential problem to the woman. Even today there are many dangers. Not sure the exact state of medicine in your world but I'd expect there to still be dangers. So, of the father cares about the (future) mother, they won't take the decision to have a baby lightly. I'd avoid most of the details, but let's say that if the father didn't care about the (future) mother, they would be free to take the decision to have a baby together. The woman doesn't exactly need to have a choice in the matter. Men can take concubines to have children with and then just "adopt" the right child into their own family. The concubines could be slaves. Or worse.

So, overall, people will be trying to get a powerful child as it's a real benefit to themselves, their family, and their community. That is despite the potential problems the birth can pose to the mother. Thus, the system where everybody has a shot at getting a powerful child, instead of that being a lucky occurrence, cannot work.

There is a way to preserve the overall idea but...

You have to change the system

The major problem is that everyone has a shot at giving birth to a powerful witch. And since the parameters are known (or can at least be guessed quite easily) then everybody can plan and act accordingly.

Here is some things you can do to make the powerful witch child a lucky occurence:

Drop the solar eclipse requirement. Make it unpredictable

The problem is that it's too easy to aim for it. Even if there is no way to predict the correct time 9 months in advance, if it's calculable at any length of time, people will try to aim for it. Just try to space out the conceptions in a community within about a week of each other and you're set - there would be at least a few mothers that will be ready to give birth about every week, so whenever the even arrives, they'd try to induce an early birth.

So, it has to be completely unpredictable. Perhaps not until something like 5-10 minute window. That way, nobody will be able to plan and try to induce an early birth. It it might not even be a global event but something highly localised in some fashion. That way, even if people from city A don't get a powerful witch baby, they wouldn't be able to know that people from city B had the opportunity to get one.

In fact, it might be best if nobody is even aware that the baby is a powerful witch at birth. Because a rival city or family might try to kidnap the baby at the very least. So, it's better if only later does their power manifest. At least around 6-8 years old would be good enough to make it feel special and lucky.

People will still try to get advantage for their children. You cannot stop that - again, just look at the real world. However, if their efforts don't work, that would limit the risk they expose the mother and the baby to.

Limit the pool of powerful witches

This could be an interesting way to keep the "lucky" element and keep the time of birth being predictable. Simply limit how many powerful witches can there be in the entire world.

As an example, in Avatar: the Last Airbender and the successor show Legend of Korra there is a single Avatar in the entire world. Once they die, a new one is born. This is heavily based on the Dalai Lama as the Avatar is partly a spiritual leader who reincarnates. At any rate, it's one way to make the "limited amount of witches available" - once one dies, they reincarnate. Or perhaps there is a different reason for the limit - maybe even unknown. It could be as weird as "there is only one per constellation and no more".

If you keep the celestial event requirement, then they can only reincarnate (or whatever the justification is for the limit) at that that point in time.

You can restrict on how many powerful witches can there be - only one, like in Avatar, or perhaps 100 or 10 000. Depends on how you want the story to go but you simply cannot have more than that number in the entire world. Or maybe there are very special requirement to join the ranks of the powerful witches and increase their number permanently. At any rate, even if one gives birth exactly on time, there is no guarantee that the child will have the powers of a powerful witch.

Do note, that this can put the witches at more risk. After all, if no more can be born now, then a simple solution is to kill one and plan a birth at the next significant celestial event. You can have quite good chances of success, then.

Make the powerful witch highly dangerous

This can make the powerful witches feel special but in a completely different way. Simply having them might be bad news. They might lack morals, or lack restraints, or be highly volatile. Or any other thing to make them incredibly dangerous. In that case, having a powerful witch child might be more of a curse than a blessing.

Here are some possibilities

Uncontrollable

The powerful witch can produce powerful magic but...not always what you want. Not always what even the witch wants.

• The magnitude of the spell they cast might be off - lighting a campfire and burning down the forest are both possibilities when they try to produce a flame.
• The effect might be unintended. Even if the witch wants to produce flame and can get the correct amount, perhaps sometimes they get a flock of birds in addition or instead. There can be all sorts of things that show up you don't want.
• The witch can manifest effects despite their wants or needs. They might need to work hard at controlling themselves to not randomly summon a lightning bolt or maybe there is no controlling that. Of particular problem might be times the witch is not in any control, for example when sleeping.
• The magic the powerful witch casts might be bound to very specific restrictions. Perhaps they cannot affect cold iron or anybody wearing it. Or people born on a Tuesday. Or other weird characteristics would come into play. So, while this might be reliably always the case, it's not going to be easy trying to determine the limits. Also, the conditions might switch. For extra fun (well, from out of world perspective) the powerful witch might get new sets of restrictions and rules for their magic instead of experiencing high and low tides. So, in effect, their magic might be powerful but would seem quite random from the outside. And they might not even be able to completely figure out the rules by the time a new switch comes in.
• The powerful witch itself might be rebellious and would simply despise following any rules or guidance. They would be unruly to such an extent that they won't be a boon to their community. Not for very long, at least.

Unreliable

This is different to the above. Instead of the powerful witch being sort of random, they would be consistent...but ultimately not very useful:

• The powerful witch has exceptional magical talents at their disposal. However, instead of being a boon to their community with their spells, the witch is lost within the world of magic. Daydreaming, fantasising, absent-minded, lost within the world of magic. It's exceptionally hard to make them focus on the real world and harder still to keep their attention there enough to ask them to do something for you.
• the powerful witch might be bound by different rules of magic permanently. So, even if they cast the same spell as a "normal" witch, they'd get a different effect. The difference in this scenario could be that it's not random...but it's still sufficiently different that it makes learning and using magic much harder. Imagine if there is a brilliant mathematician but for them calculating 2+2 always yields 5. A triangle for them will also somehow have two sides. The rules just don't work the same as for anybody else. So, they can still be of benefit but it's hard to work together and especially hard to get a specific effect.
• The witch just cannot understand others. Either cannot relate, or tends to misinterpret, or literally is unable to comprehend communication. It makes the powerful witch exceptionally hard to deal with.

Evil

As an example, the tabletop game Mage: the Ascension has the widderslainte. These are mages who followed a dark path in a past life and managed to permanently taint themselves and essentially turn to evil magic. Once they reincarnate, they don't remember any of this but are still evil and uncontrollable psychopaths even as normal mortals before the Awaken (read: become mages). Once they do, any magic they cast is evil and twisted. In the Mage cosmology, the source of magic is sort of separate from the human who wields it. So, it's in theory possible for the human to be redeemed (but exceptionally hard), yet they cannot cast anything but magic that is corrupt and brings harm and ruin to the world. Even killing a widderslainte doesn't help much as they would just reincarnate and you'd have to face them again.

So, working with "widderslainte"-like idea - perhaps the powerful witches are also unable to do anything but harm. So, having one in your community is probably bad. If they not only wield "bad magic" but are also bad people, you definitely don't want them around your family or your community. Just imagine a bunch of little Damiens from The Omen.

This has to actually be counter-balanced in some fashion because of the powerful witches are so undesirable, people will steer way clear from giving birth to more and can even just kill the child young or even the mother than let one loose in the world.

Answer 2

Solar eclipses on Earth are quite rare already and short (less than two hours). Only one in 25 pregnancies ends in exactly 280 days (the average), that means even if you time the fertilization right, chances on success are at most 1 in 400. (Less if the mother isn't fertile 280 days before the eclipse.)

Giving birth is already dangerous, but suppose there's some magic involved such that during an eclipse this danger is greatly increased, to the point of likely killing mother and/or child. That would actually discourage partners to plan births during eclipses; only unplanned births (perhaps by less educated couples) would have a chance to occur during an eclipse.

Answer 3

You need two things:

1. Give the world multiple suns. An eclipse is only when only one is in the sky and the moon covers it. With three-or-more body problem, the eclipses become impossible to predict... even with modern computers it’s near impossible.

2. Any child born by cesarean section has no magic. Magic requires a hormonal change in the mother that only happens during actual birth. Once they have the medical tech to induce births, you may have a problem (you’ll need another explanation).

Answer 4

The celestial events at birth are just a coincidence. What's important is celestial events at the moment of conception. (Or, alternatively, a specific moment after conception when the embryo develops enough complexity to begin forming/hosting a soul - perhaps 27 days? Assuming that 3 is a magically powerful number, and 3³ is more so...)

After copulation, conception (fertilization and implantation of the egg) can take place anywhere from a couple of minutes, all the way up to 5 days later. This makes controlling the time a lot more difficult than simply getting roughly in the right ballpark and inducing/preventing labour according to a "magic moment".

Due to this delay between the visible act that kicks things off, and the important one that actually determines mana content, it has been overlooked - and everyone is obsessed about the completely irrelevant moment of birth.

(This then lets you set up a character who was born several months premature - both physically weak in early life, and believed to have a low mana content, they are surprisingly powerful once they grow up...)

Answer 5

My suggestion is rather straightforward: specify that a total eclipse is required at the relevant point in childbirth, and you're good to go, for several reasons.

One: Biology does not tend to be perfectly predictable; you don't need magic to impose severe limits. Conception is by no means guaranteed on any given day in humans. Childbirth can happen in a fairly wide window (several weeks of variation, even before you include premature births). Childbirth itself certainly does not take a fixed amount of time. Put the points together, and only a fraction of those who plan for a child to be born on a specific day will actually manage that feat.

Two: A partial solar eclipse is fairly straightforward, but (assuming that this is functionally Earth) you are limited to at most two total eclipses per year, and they cover a comparatively tiny section of the planet's surface; any given location will only ever see a few total eclipses in an individual's lifetime. There's just not going to be that many opportunities for any one community to even try for a child during the eclipse.

Three: A total solar eclipse lasts for all of eight minutes at any given point. Even if we assume a thousand mothers give birth on the same day at the same place (fat chance of that), on average only about five or six children (assuming each mother gives birth to one living child; twins, stillbirths, etc., could affect the numbers) will be born in those crucial few minutes. Even with modern medicine, I'm pretty sure birth cannot be induced for so precise a timing. Even a C-section is unlikely to be that exact, never mind the fact that that is actually a very hazardous operation in older times that often killed the mother (or the magical ramifications of circumventing the normal process of childbirth, which are whatever you want them to be and could easily include weakened or nonexistent magic).

Four: You say that the solar eclipse needs to be when the child is born. At what instant is that defined for magical purposes, seeing as childbirth can go on for hours? Is it when labor starts? When the mother's water breaks? When the baby enters the world? It doesn't particularly matter for this answer which one you pick, as long as you pick a point and run with it.

Conclusion: You don't even need to discourage parents from trying to exploit the eclipse, and in fact it makes for an interesting source of conflict (read: excellent plot material) as parents try to manage it. Almost always, they're going to miss that crucial slice of opportunity no matter how hard they strive to catch it. Lots of potential for bitterness, angry parents (especially royalty), etc., so use it!

Answer 6

Various answers to this will probably require the world to either not be as you've described it in some detail, or to add other details.

For instance:

• What if eclipses aren't easy to predict? Frankly, it wasn't until the 1500s that Western civilization rediscovered the heliocentric theory and solidified the math of orbital motion behind it, and it wasn't until the 1800s that the knowledge of what caused eclipses and they weren't the end of the world became common enough that men didn't kill their whole families to save them from the apocalypse when they saw one.
  • That might not make sense in your universe given the importance of what an eclipse does, however what if your planet doesn't have its own moon? What if eclipses are caused by an occlusion of the Sun by another planet, like a gas giant, which orbits the Sun within your planet's orbit in a more complex precessing pattern, and is hard to observe when not close to eclipse? What if the resulting eclipses are so far apart that they, and the people born under them, are the stuff of legend passed down from your great-great-grandmother's generation?
• What if gestation period wasn't predictable? It's practically impossible for even modern humans to predict a natural childbirth to the day (elective Cesarean is "cheating" in this regard, and you might make it so that medical intervention to induce labor spoils the effect in your universe). Gestation times might vary widely between women or even between pregnancies due to the influence of their magical powers or other handwaves like genetic variation in the population; so, even knowing that an eclipse is likely within the average gestation window, it would be useless to try to figure out the exact day or month you should try to get pregnant in order to even have a better chance of giving birth at the exact moment of an eclipse.
  • Along similar lines what if the eclipse itself caused magical changes that affected pregnancy? Even if your due date was on the day of an eclipse, the impending eclipse would push onset of labor to either side of it, inducing mothers early who are further along before the full eclipse, and/or delaying other mothers' labor days or weeks, making it that much rarer for a mother to fall right on the knife's edge and give birth during the eclipse?
• What if there's a tradeoff? There commonly is a balance in human traits between things we value and things we avoid. Exceptionally high intelligence stereotypically comes with a dearth in social or soft skills and in physical strength, the extreme being savant syndrome which is often co-diagnosed with an autism spectrum disorder. In your universe, someone born under an eclipse might gain a stably high level of magical capacity (mana), but this blessing could be its own curse:
  • The higher mana levels might cause mental or emotional instability.
  • The higher mana may require the person to use magic uncommonly frequently to keep their mana from "overflowing" with destructive consequences (which could violate social conventions or taboos about the use of magic, like not "showing off", that makes them a pariah).
  • Mana may interfere with physical development, so eclipse mages are frozen in a childhood form, or conversely age very rapidly (whether this affects actual lifespan is your prerogative).
  • Higher natural mana may make the person physically frail their whole lives, unable to do much of anything except by using magic.
  • The higher natural mana may be coupled with a magical version of savant syndrome; the eclipse mage might be exceptionally gifted not only with a higher natural supply of mana but with a talent for a specific type or school of magic, but they are far less talented or even incapable of even the simplest spells of another basic realm of magic. Meanwhile other mages are "jacks-of-all-trades", with competency in multiple magical areas, nothing world-shattering but definitely enough to handle themselves in general.

Answer 7

They're not given a choice of birth date.

An ancient and powerful spell covers the entire world. When someone wishes to have a child, they perform a ritual and recieve two dates - a date of conception and a date of birth. It is impossible to become pregnant outside of your day of conception, and you will give birth on your day of birth. Trying to circumvent the day of birth is... unwise. The best case scenario is that the child dies during the attempted induced labor or c-section.

Nobody knows where the spell came from. The leading theory is that the witches in deep antiquity created it to solve the problem of eclipse babies, but another popular theory was that it exists to prevent unwanted pregnancies. (It is not entirely successful at that. Never underestimate humanity's ability to frustrate even the most idiot-proof systems.)

Answer 8

In addition to all proposed solutions, you could add a sort of clause.

The birth has to be natural. If the mother tries to force the birth of her offspring prematurely in order to make it coincide with a celestial event, it will interfere with destiny, or the natural order of things and render her baby a creature incapable of performing magic (or less attuned to magic, if you wish).

Answer 9

You need to consider two points.

1) Why is it a problem? (To the society, and to you as an author.) If there is a system, people will attempt to game it. That's just natural, people send their kids to Eton to try to give them a better chance at life and I would expect if they can game the birth system to give their children a better chance at being powerful mages then they would do so. I don't see who loses out - the parents get a baby with better life chances, the society becomes more powerful because it has a greater number of powerful mages, and the babies who are not born at the correct time are no more disadvantaged than they were before (and perhaps less so, because if there are more powerful mages around then there is greater competition so the prices of mage services should decrease).

2) What specific aspect of being born is it that triggers the person's mana level, and how? On one hand, the baby is already fully formed before the time of birth and there is no substantive physiological difference between the unborn baby at t-1 day and at t+5 minutes. On the other hand, birth is traumatic. You get squeezed through a small tube, go from a comfortable warm place into a cold place, have to breathe for yourself, no longer receive nutrients through the umbilical cord and so on. So perhaps it's this moment of trauma that sparks something in the mind and establishes the connection with mana. Babies born by Caesarean section experience less trauma than vaginally delivered babies, and perhaps C-section babies, even if born at the correct time, do not bind to the mana to the same extent. Natural birth is difficult enough to predict that if the mana binding requires the trauma of natural birth then you don't really have a problem. (I guess if that's the case it could lead to the awful prospect of people trying to game the system by beating their C-section delivered newborns to increase the trauma, which would be horrible.)

3) Balance the gift some other way. Perhaps babies most closely attuned to the mana are limited in some other way. The connection might stunt their growth: the idea of mighty but physically puny wizard is already pretty much stereotypical. Or perhaps it renders them infertile. Mages then would be respected for their magic powers but not necessarily all-powerful or even particularly envied.

Answer 10

Solutions:

1) Make it less predictable. Add more satellites to the planet, to calculate orbits of more than 2 bodies is actually hard!

2) The Government actively hunts eclipse babies. They are feared and coveted, some groups hunt them to kill, other to forcibly recruit them.

3) Only naturaly born on the eclipse count. Eclipses last mere minutes, and it is impossible to calculate conception with such exactitude. Artificialy born in eclipses (C-section or the such) behalve like every other witch.

Answer 11

I have 3 suggestions, none without their problems.

1. People don't know about the eclipse correlation

The first possibility is that while this does occur, people don't know that a solar eclipse is the cause and just think that these people are lucky. Of course it might be difficult to prevent them from finding out, especially if it's a sort of enlightened, scientifically minded society, as they might be trying to figure it out.

But the occurrence is so rare that it wouldn't be noticeable to an individual, only to someone who did a survey of many such children with this power. And depending on the type of society we live in, this research might not be carried out, or might be carried out by only someone with the wisdom to recognise your concern (perhaps by these witches themselves) and it remains a closely guarded secret.

2. Economy II

(Inspired by kleer001's answer) Demand on maternity services increases around eclipse time (and maybe the process is more complicated given all the magical stuff going on) so parents have to pay a lot of money to have a baby delivered around this time. This would discourage them from planning a baby at this time. Of course this will just result in mainly rich children gaining the benefit. Not the kind of luck you're thinking of, I think.

3. True love / lust is also required at conception

You could add a condition - that the child must be conceived in an act of passion/love/lust - practical considerations must not be on their minds. This would rule out forward planners, but also possibly most planned pregnancies whether the date is on their mind or not.

Answer 12

I've found that in worldbuilding there are few problems that cannot be solved by a massive, worldwide, theocratic bureaucracy. You need one randomly selected person from each town to be executed at the end of every year that begins on a Friday? Massive theocracy. You need an entire country to refuse to leave their houses on the first day of every month? Massive theocracy. You need people to wander into the desert on their sixteenth birthday, get high on weed for a week, and then come back? OK, technically that can just be sixteen-year-olds under their own initiative, but you see the point. The solution in this specific case is quite simple. You want an ordinary number of births during the eclipse, and for those who are born during the eclipse to be considered lucky.

All we need is for that Perfectly Legitimate, Ordinary Theocracy, aka a Diety-worshiping Establishment of Very Interesting, Completely non-Evil bureaucrats (henceforth PLOT DEVICE), to carefully take account the number of births throughout the time between eclipses. Then, 42 weeks before the next eclipse, the members of PLOT DEVICE divide this number by the number of days that have elapsed since the last eclipse, to get an average number of babies per day. They then proceed to separate all men and women into distinct groups throughout the entire world, with no intermingling, for four weeks. The only exception is a number of couples, chosen by random lot from all interested couples, equal to the number of babies required for that four-week period, as previously calculated by PLOT DEVICE, multiplied by a "fudge factor" for couples that fail to conceive. Then, nine months later, the babies are born, roughly within that four week period, with some overlap around the edges. Almost all babies born on the day of the eclipse are babies from those couples chosen randomly, thus, such babies are seen as lucky (having been born to lucky parents), and we get no unusual spike in childbirths.

Tada, all our problems are solved by a massive worldwide theocracy. Why does the theocracy do this? Because their deity told them to. That's been a good enough justification for ritually murdering tens of thousands of people each year, it's good enough for this too.

Answer 13

There's a great downside--the child's power comes at the expense of the mother's power. The child always has high manna--so the mother always has low manna.

Answer 14

Two things, I think, would help your plan.

First, you'd need to have a penalty for trying - if there's no cost, and possible gain, from having a baby around that time, then that's what folk will do.

One option may be children who will be born near-but-not-exactly-on-the-eclipse are generally weak, unlucky, low manna, etc. Various methods of interfering with pregnancy or birth to try and force a specific outcome may negate the potential for eclipse-born, or guarantee bad luck/low manna, or something. If the gamble is very unlikely to be (very) good for a kid vs very likely to be (very) bad for the kid, well, that'll change people's risk assessments, and so fewer kids will be born around that time (as much as folk can manage). It might not be enough on its own, but it can help... especially if one does another thing:

The other thing is, you can take that chance of bad luck and think to ask what folk do know. If the timing surrounding an eclipse is very broad for bad luck/low manna, and narrow for good luck high manna (someone else was saying eight minutes?), if folk are relying on tradition from before people have precise-to-the-minute clocks in widespread use and the skills to use statistics, if there's no really strong reason what folk would "know" would be accurate... well, everyone knows eclipses are very bad times for childbirth, the babies have low mana and bad luck, really, who would ever want their kid born anywhere near that time - um, no one! Oh, now and then you'll get an odd exception that has high manna and tons of luck, but folk wouldn't necessarily know why (especially before time was tracked with minute-precision). Maybe it was the parents, or fate, or suspiciously-specific rituals, or ancestor-spirits, or the meddling of gods that cause this child or that to be the exception.

To be fair, you'd still get folk trying to game the system (some might even succeed). but most wouldn't know what system to game, whether it's precise timing or rituals or sacrifices or bloodlines or talismans or various things done/not done along the way. Folk might figure it out once birth times are routinely tracked, and eclipse times (to the minute) are recorded, and someone runs a statistics search... but by then most would already have found something to believe from the traditions and rituals and explanations of older history.

Answer 15

Unpredictable gestation periods

In our world, babies are in the womb for more or less the same average time, regardless. No matter what the pedigree of the child, it always takes approximately the same amount of time (ignoring preemies and what have you.)

Your world doesn't have to follow this. It can differ from ours however you like.

So change it. In the one extreme, a few instances have been recorded where a child has to have been conceived at most a mere one month before being born. But women are also regularly with child for more than a year, and the most extreme verified case is more than three.

What's most important for your problem is that the standard deviation is large, and that it not be predictable. People in the world can't be able to say "well, John and Leah's last two children were both 10-monthers, so their next child will probably be 9 to 11 months". It needs to be so random as to be essentially unpredictable.

If the "average pregnancy" lasts, say, nine months - but comes with a "plus or minus six months" qualification, it is essentially impossible to predict when any given child will be born, and thus the system cannot be gamed.

This also gives you an opportunity to divvy out abilities and skills, by associating types of magic to specific gestation periods, but specify so little is understood about how to affect gestation periods that it is effectively uncontrollable.

Answer 16

Economy.

Have these Eclipse born also get some kind of balancing detriment. Maybe their mana is larger to begin with but takes longer to resupply? Maybe their spells are less likely to work? Maybe they're outcasts as everyone is afraid of them?

You should be doing this with your magic system on the whole...

That is managing your costs to balance with their benefits.

Brandon Sanderson does a great job of this:

https://coppermind.net/wiki/Sanderson%27s_Laws_of_Magic

Another good source:

https://mythcreants.com/blog/how-to-create-a-rational-magic-system/