One thing that I have sitting in my grab bag of jigsaw pieces for creating homebrew d&d (or other fantasy) settings is this idea that, when you're making an character and all elves speak "elvish" and all dwarves speak "dwarven" and humans speak "common and one other language of your choice," that's not just a game mechanic, it's because humans are the only people who don't come with an external language hard-coded into them.
If you take an baby elf and dump him in the woods to be raised by wolves, thirty years later he's still going to be mutually intelligible to any other elf he comes across. He didn't have to learn the language because it's just a thing that he can do, as an elf. And humans don't have that. They have to build their languages as they go. That said, that degree of flexibility and the fact that humans are really good at developing trade languages as a result is part of what led to a certain human pidgin eventually evolving into the global lingua franca, aka "Common."
Part of this you can also tie into the fact that, in a lot of settings, there's not a "human pantheon" either. The elves have their own pantheon, and the dwarves have their own pantheon, but the humans worship a fantasy version of the Norse gods or the Egyptian gods or the Olympians, with what pantheon the humans worship often changing depending on what part of the world you're in. Maybe the humans committed some unspeakable sin or unforgivable hubris that shattered their ties with their creator. Maybe the first gods of the humans are dead. Maybe they died saving their creations from some great threat. Maybe they died at the hands of the humans themselves. Whatever the truth is, knowledge of it died with the Human Tongue.
If you really want to engrave this idea into the landscape of the setting, you could even take it a step further. Maybe each race has a Heavenly City created by their gods in a past mythological age. The elves still live in their city, with some family lines having lived there for, as near as anyone can tell, literally all of recorded history. The orcs likewise still inhabit their holy city, but it's been conquered and partially rebuilt by different factions more times than anyone can count, since conquering it is seen (somewhat justifiably) as either possessing or forcibly claiming a divine mandate to rule. The dwarven homeland has fallen, taken by a great enemy, but at least they know right where it is, it's just a matter of retaking it.
The human Heavenly City is just gone. Might as well never have existed. Nobody knows where it is—or was—on a map. Sure, different empires have claimed their capital as the Heavenly City, but it's always been propaganda. The humans are a lost people. Wanderers, in a sense, even when they build lasting nations.
Whatever caused the humans to lose their Language could also be part of why they're so good at hybridizing. There's a bit of their spiritual DNA that everything else has that's been stripped away, but that can be filled in by other things. That's how you get half-elves and planetouched and so on. You don't get elvish tieflings no matter how many infernal pacts their ancestors enter into, because an elf has that little something extra inside them that always says "you are an elf."
#how do the other pantheons view humanity? Did they know the humans' gods? Did the memory of the human gods very existence get wiped out?
As a general rule, deities tend to be reserved about the actual mechanics of the divine realms and the afterlife, something that they enforce on one another. That includes what they know about what happened to the human gods. As for the reason they're so quiet... I'll lay out a few possible scenarios about what caused the human collapse, as well as how that feeds into the other pantheons' reactions. None of these may be true, or more than one of them may be true, with parts of them overlapping to provide the whole story.
The singular human creator diety died driving off or sealing a great evil before any of the humans could ascend to their pantheon. The other gods don't speak of this because knowledge concerning the great evil is too dangerous to let spread.
Humans grew proud and built a great tower to the stars. They reached out for power, and in doing so they invited in something from beyond the boundaries of the world. They used its power to kill their gods, but the power shattered their minds in the doing. The other gods do not speak of this because they themselves don't completely understand what happened, and that terrifies them.
The first human deity was a cruel master, and their creations rose up in revolt and shattered their divine throne. The other gods do not speak of this because they do not want anyone to know that they can be killed by mortals.
The human gods were being corrupted by an outside force. Their death was a suicide—or, at the very least, they allowed themselves to be killed—rather than allow themselves to be taken over completely. The other gods do not speak of this because they quietly fear that the same could happen to them.
The human god was struck down in battle, or in a quarrel. The other gods never expected what would happen to its creations. They could not have expected. Forgive them. Forgive them.
The gods are not above mortal failings. The hands of the divine are not free of blood. The human gods fell for the same reasons that men do; jealously, betrayal, and lust for power. The other gods do not speak of this because it is better for their friends to be forgotten then have their memories sullied.
A god cannot die as long as their name is spoken. The humans didn't lose their language because their god was killed; they lost their god because someone killed their language. The other gods do not speak of this because they fear the human god's return.
#do you think you'd make the gods permanently gone (disappeared or dead) or recoverable/reconcilable?
The general consensus of most religions is that the original human god and/or pantheon is Capital D Dead, because if they weren't then someone would've had some sign of them since then.
That said, there is a cluster of human religions who think that "The Goddess" disappeared and 'freed' them from a common language deliberately, either as a test of character or because she wanted humans to grow into her equals rather than being completely subservient. And some people in this religion have demonstrated what looks like divine magic. Now, that could be rationalized away as them having made a pact with some sort of celestial, or unknowingly drawing on some sort of natural source like druids do, or being given miracles by an unrelated trickster deity to sow chaos, but still...
#what kind of prejudice exists against humans bc of their situation?
Humans are the redheaded stepchildren of the world. Scattered to the winds as they were and with no Heavenly City, humans collectively spent a lot more time as nomads and hunter-gatherers than other races, which feeds into stereotypes of them as vagabond barbarians, even long after most humans have become settled in one place. However, in a slightly less negative light, it feeds into stereotypes of them as explorers and, especially in ancient days, cavalry. The latter stereotype eventually bled over to orcs as well, especially in areas with lots of interbreeding between humans and orcs, but humans were the first masters of mounted combat.
In magical terms, humans lagged behind other races for a long time, due to their early lack of divine patrons and a lack of a singular language forcing them the reinvent the wheel several times on basic arcane practices. One thing that they can do as well as anyone else is make pacts. That, coupled with the fact that tieflings and other planetouched are descended from humans, has led to human casters being stereotyped as warlocks (and conversely, warlock pacts are sometimes disparagingly referred to as "human magic"). Additionally, the oldest human druidic traditions rivaled and maybe even exceeded those of the elves, though they've dwindled over time as humans urbanized and other forms of magic became more accessible to them.
That said, there's nothing that prevents human mages from studying the magical arts of other cultures, especially if they learn the language. As of about 300-400 years ago, the big human empires are basically caught up with everyone else in terms of the arcane fundamentals. At this point, the disparity in magic is mostly a matter of ubiquity; to a human, "wizard" is a thing that you are, but to an elf, "wizard" is a job that you do.
As a general rule, humans fall somewhere between the other Elder Races and the Young Races in the nebulous pecking order of the world. They're numerous and widespread, they've got a strong sense of their own history and identity (even if that identity isn't as homogeneous as everyone else's), and some of them have ascended to godhood; the Young Races tend to be lacking in at least one of those advantages, often multiple.
Like I said, redheaded stepchildren, but they're successful redheaded stepchildren, and that counts for a lot.
against halflings?#how do halflings work in this situation? are they humans (no language) with Other traits or Other (language inborn) with human traits?
To me, Halflings (or "Burras"), having their own racial language, are an Other who just happen to share a lot of traits with humans. But, then again, so do elves, and like elves they're also different from humans in a lot of respects. For one thing, burras are Lucky. For another, they're resistant to fear. For a third, they're short; they exist at a different scale than everyone else except for maybe gnomes and goblins. Those three things together paint a picture of a race that lives in a slightly different world than everyone else. It's not that they're reckless daredevils or blind fools or somehow immune to misfortune, it's just that they roll with things in a way that everyone else doesn't. They're no more or less intelligent than a human or a dwarf, but they are clever. Their adventurers are bards, they're rogues, they live in a world populated by them and a bunch of giants. They're an entire species of Jack and the Beanstalk protagonists.
All that is generalization, of course, but compare it to the generalized picture that I painted of humans up above as horsemen, warlocks, and hard-bitten explorers, and you can clearly see the differences.
#how did the humans new gods arise? what would the old gods return do to them/to humanity?
Alright so there's basically two ways to become a full deity, in my current working version of this setting. The first is to actively be uplifted by an existing pantheon, which is easier if you have divine ancestry. The second is that if you were exceptionally powerful in life, there's a chance (albeit a minuscule one) that you'll ascend to godhood 200 years after death (i.e. once your connection to the mortal plane finally snaps and you're beyond being resurrected).
The general line of descent goes like this:
Everything begins with either Primordial Chaos or the Big G God, currently undecided.
Patron Gods are formed.
Each Patron God creates an Elder Race (dragons, humans, elves, dwarves, halflings/burras, orcs, giants, maybe one or two others) in their own image.
Some members of the created races are either uplifted or ascend on their own, forming racial pantheons with a Patron God as the nucleus.
Celestials are either created ex-nihilo by a similar process to the ones the Patron Gods used to create the Elder Races (angels and co.), or literally birthed by godly parents (lesser deities).
Full deities begin creating new mortal races (the Young Races), experimenting with the humanoid template and giving rise to a lot of the more animal-themed or exotic races. Additionally, some Young Races are created as offshoots of Elder Races due to curses or other extreme transformations.
Human pantheons tend to be a lot more loose-knit, with different lineups based on region than a single universal one, plus different cultures using different names for the same gods. Collectively, they outnumber any other pantheon, but a lot of that is lesser deities who were born to ascend humans; they can empower a handful of clerics, but their scope is smaller, so they tend to focus most of their power in one or two areas (feeding into the tendency for human religions to vary by region), and they can't create new races on their own or uplift other people to deityhood.
Human deities do sometimes, if infrequently, get non-human worshipers. A few ascended humans have been folded into the edges of other Elder Races' pantheons in the same way mortals might form political alliances (including using marriages to seal the deal). Young Races tend to have the strongest affinity for whatever pantheon created them, but it's not uncommon for those with a lot of contact with humans to adopt their religious practices instead. The reverse—a human worshiping the deities of a different Elder Race—isn't unheard of, but it's a lot rarer; it goes back to the whole language thing, where a human lacks this innate bond with an elven deity that an elf or even a half-elf would have.
There have been other instances of full gods being "killed" after the fall of the primordial human gods, but never an entire pantheon at once, and there's usually an element of either divine reincarnation/time lord-style regeneration or "our god's just sleeping and will eventually awaken" involved. Every time this happens is still a major upset in the setting, but it seems like it's not the same thing that happened to the human gods.
As for what happens if the old god(s) return; anybody's guess.
