Forty five years ago, the world was a different place.
There were no character screens, there were no random numbers, there were no class unlocks, and if you wanted to craft something you had to do it the old fashioned way, with lots and lots of practice, time, and education.
Back then, luck was pretty much unseen, invisible, and more often than not entrusted to Rando, the god of the unexpected.
But everything changed, when the event happened.
The first notice some communities had of it, was when meteors started dropping out of the sky, monsters blitzed forth from the wilderness, and plagues struck without warning. It was sheer chaos for a while there, and it took the various sages, mages, and other learned folk a while to make sense of it.
Luck was a quantifiable thing now, and the lower YOURS was, the more bad things would happen to you.
And then the first wave of births after the event hit, and many prospective parents found, to their dismay, that when people are born their luck is the lowest it's ever going to be.
Human infants come out of the womb at around 25, plus or minus a few variances for reasons nobody's ever been able to figure out. Other races, like orcs, average in at 12. That's roughly out of "inexplicable meteor" range, but still around "lightning magnet from freak storms" range.
Some people whisper that given how fast orcs breed and how many they drop, it's probably best that the orcs were hardest hit during the event, while everything was chaos and many established communities were struggling to recover. This is a commonly-held but rarely voiced sentiment, especially around orcs, half-orcs, and other "uncivilized" races like goblins, gnolls, and football hooligans.
At any rate, clerics petitioned the gods for an answer, particularly Rando. But most prayers to him were met with uncontrollable weeping, so a horrible theory began to surface;
Whatever had happened, the gods were not behind it. In fact, they were no longer in control. (If they ever had been, some heretics whispered. Those guys mostly got burned for saying that.)
But the gods could help in other ways... as could practitioners of the world's oldest profession.
What? No, not THAT. I'm talking about midwives.
Clerics have access to the Blessings skill, which allows them to massively boost an attribute on someone they bless, at the expense of tying up some of their sanity while the blessing is going. Thus they were able to bless newborn infants, until the kids were able to get their luck up out of the danger zone.
Midwives have an even more specific, if less effective blessing that lasts for years, boosting the child's luck while diminishing a bit each year. While not as effective as clerics, midwives are also very good at things like washing up all the blood, getting the baby out alive, that sort of thing, so generally what most people who can afford it do is hire a cleric and a midwife to be around for the birth. This is why rich kids are generally luckier than most other kids.
Of course, blessings wear off, and luck is slow to grind through normal life.
Then someone realized that games of chance could, eventually, raise your luck.
It was a small farming family of halfen who invented grindluck, a mind-numbing color-matching game that depended entirely on the luck of the draw. And halfens being halfens, they made it both thoroughly boring and easy enough for a toddler to grasp. Grindluck did the trick, and selling the decks made the family rich, so it did the trick not only for kids, but for those specific adults, as well.
Grindluck stops being effective around luck rating forty, but by that time most kids are sick of playing it anyway, so it's a moot point. Since then, worn grindluck decks are handed down as family heirlooms, in the generations that followed the event.
For those "uncivilized" races without clerics, such as orcs, they had no real clerics, or clerics were rare enough that they weren't an option for most. So they fell back on tribal ways. Midwives were still a thing, and that helped, but the entire tribe would band together to raise children and protect them, and help them grow. Some of the more clever tribals hit on things like grindluck, but playing more to their harsh ways. Similar games with higher stakes, like "poke the bear," or "blindfold and try to eat the right mushroom" worked in a pinch. But ultimately, the most pragmatic shrugged, and threw their kids into the hardest challenges possible that they could reasonably withstand. The strong ones would survive, and gain luck and other stat boosts for surviving. The weak ones would die anyway.
Rando's no longer taking calls, so the position of god of luck is vacant now. Although rumors abound of a goddess, whose name is unknown but whose initials are RNG. Evidently she's also responsible, now and again, for pulling people from other worlds into Generica. Or at least blamed for it. But anything else she does is a mystery, and she seems to like it this way.
Clerics of luck still find their prayers spells work, but nobody talks on the other end. But if they talk into the emptiness, rather than guidance, sometimes something totally random happens. Which is why clerics of luck save their prayers usually for when things absolutely can't get any worse. Because they know the odds, and that the house always wins.
What of Fortune and fate? Those mysterious things, which combine luck and perception? It's speculated that they fit together because one's fate isn't just luck, but recognizing your opportunities when they come.
Fortune, like any other attribute pool, is used to power spells and skills which require it. There aren't many of those, except for those who have the bard, grifter, or oracle job, or a few odd second tier jobs. The monsters who attack your fortune range from small annoyances like gremlins, to the overwhelming divine servants, who can erase you from reality if you blaspheme too much.
Fate, like any other armor, reduces the effects of spells and skills that target fortune. It's also one of the hardest armors to raise. Normally it raises naturally, being equal the highest class level that a person achieves. Some races, like halfen, get a boost there anyway. But beyond being armor of a sort against special attacks, no one's quite sure what it DOES.
There's at least one second-tier job that revolves around luck, the gambler class. It's all about luck manipulation and stacking the odds, though for reasons unknown it's also about throwing magical cards and dice as weapons and causing giant slot machines with random magical effects to materialize. It's unlocked through the archer and grifter classes, oddly enough. Most gamblers, when they're done adventuring, usually settle down and open up casinos. Either that or use their airships to crash perfectly respectible opera performances. (Though there's only one event of that nature on record people still talk about it today.)
Some speculate that it's possible for someone to be born into a racial job so weird and unsuited to the world, that their luck would have the chance of being in the single digits when they're born. But that's ludicrous, frankly! Their early life would be a series of nigh-unsurvivable events, culminating in tragedy for the parents, the child, and all involved! Surely the gods would not allow it. What species indeed would be capable of surviving such a thing?
No, the very idea is foolish.