Where do goblins come from?
While only the most skeptical of city-dwellers, insulated from the terrors of the wilderness, would opine that there are no such things as goblins, those that have encountered them are largely at a loss to explain their origin. Though many a hero for law and goodness has worried about the ethical conundrum that would entail from finding innocents of the species, none know of such a thing ever happening. Occasionally, a nest or warren of them is found that, if squinted at, seems like a cruel mockery of a town, but there is no real evidence of a greater culture or interaction with other goblin groups. Most religions write them off as merely the sins of the kith personified, to be killed on sight.
They’re not far wrong.
Another great mystery of the world is the nature of heroism. If a city gets large enough, it begins to train advanced techniques in the pursuit of battle, craft, and magic. Those that spend years and years training at colleges and gaining experience in the world can become extremely competent. Most humans and similarly-lived kith may master complex techniques equivalent to the third circle of magic before they enter their dotage, but it takes the lifespan of the elves to truly master such techniques. Still, only the most ancient of the elves, sequestered deep in their lands, profess to understand magics of the ninth circle.
Yet, there are constant tales of small groups of adventuring heroes that seem to have mastered skills while still young that rival the eldest scholars of the land. They don’t like to speak of what makes them different, if they understand at all.
There is a theory called spontaneous generation. While learned sages with an interest in experimentation are convinced that flies work much like moths, laying eggs that grow into maggots as a larval form before eating enough offal to become flies themselves, most common folk do not have access to this science. As far as they know, maggots and flies are spontaneously generated from rotting meat. When they leave meat to rot, maggots appear as if from nowhere, and flies thereafter.
They think the same thing about goblins, and they’re missing the point in exactly the same way.
Goblin hierarchies don’t make much sense. If they didn’t look similar in general shape and work with one another when no one else will, none would believe that the cowardly goblin, organized hobgoblin, and bestial bugbear were of one race. Were any hero to ever find evidence of a goblin civilization, it would have to explain much about the processes that could result in such differentiation in both size and temperament. Why are there no cowardly hobgoblins or organized bugbears? Does growing past a certain size change their entire mental state?
It all comes down to the flies.
Goblin flies are distinctive, if you look closely enough: greenish and with a goblinish cast to their features. Few have made a study of the differences, because they come in a swarm unaware on small villages far from scientists, and few kith tend to survive to spread the tale. First, they bite the livestock and small animals they can catch. The beasts get sick, and many of them die from the strange pox. If you don’t burn the bodies quickly enough, the larval goblins within manage to eat enough to burst free, fully formed. Their first task is to try to add more offal to the piles of their nascent siblings, creating enough rotting meat to build a whole goblin. Some say, in the death throes of the illness, the smallest animals are driven to seek out piles of other dead to add their own meat to the stores. Deep in the woods, sometimes a big predator falls ill. While prey and vermin universally produce the small goblins, a big enough predator can result in a bugbear. Those that named it must have known better than any ever guessed what was going on.
Kith are harder to bite, and tend to resist the illness better, in the early days. But as the goblins kill the livestock, foul the fields and the water, and wear down the town’s guards with their attempts at incursions, it becomes harder and harder to stay healthy. Once the disease takes, the people fall just as ill as the livestock. There’s something about the minds of the kith that speaks to the growing goblin, and so the hobgoblins that burst forth from kith corpses share the kith tendency towards organization and structure that their brethren born of beasts lack. Never think of them as your loved ones turned into hobgoblins: that’s not your friend, it’s what ate her from within. Any similarities are just echoes of her mind that the larvae picked up.
Sometimes, though, an infection gets resisted. The healthy, or just the lucky, overcome the disease, purging it from their systems. But something of the magic remains. Perhaps it was the soul triumphing over the evil of the goblin plague, or the strange effects of magical fever dreams, but the survivors gain powers. For kith, this is one way that an adventurer is born: somehow, it’s much easier and faster to pick up the skills of battle, craft, and magic than for others. For beasts, this is often how the stranger magical creatures arise.
Adventurers don’t like to talk about it, because for many of them their first adventure was using their newfound strengths to purge the goblin infestation from what was once their idyllic village home. Often there’s not much left. They adventure because everything they know is gone and, if they’re honest, they’re seeking an answer to what happened to their families.
It’s clear that the goblin flies aren’t natural. They choose their targets. They come when those villages are least able to defend them. Somewhere, there’s a malevolent intelligence directing these swarms to bring ruin upon the lives of well-meaning settlers and peasants:
A lord of the flies.
System sans Setting 