Ever-present and involved in seemingly every significant development in the last few thousand years, planar or Prime, it's nearly impossible to travel the planes without encountering humans. Yet with no cohesion tying them together, no common thread of origin uniting them, to most native planars their enduring existence is little more than a footnote, bearing little import to what many see as the "true" power of the planes; more the fool they.
Humans were one of the first mammalian species to arise in the Prime, with their first recorded appearance between 35,000 and 40,000 years ago across multiple worlds. For millennia, they were a largely unimportant species, barely noted in the greater scheme of things. On what Prime worlds of significance there were at the time, they were for the most part irrelevant, dominated by the reptilian species that then held sway over most material worlds. Upon the rise of the Illithid Empire, they served as the illithid's prime slave stock, likely due to the ease at which they could be psionically dominated and their relatively short lifespans compared to most of the then-insignificant species. Though already present on a wide number of worlds, their place in the squid ships of the illithid spread them even further, bringing them to every corner of the Prime.
On one world, breeding experimentations by the illithid brought forth the species that would eventually divide into the githzerai and githyanki, but on most, the human stock was left largely untouched. Thus it was that upon the fall of the Illithid Empire 16,000 years later, many worlds were primed and ready for new human civilization, even as others that managed to avoid the touch of the Empire — such as Oerth, Akar, Krynn, and other now-major worlds — had been slowly ascending all this time with no abandoned flayer artifacts to aid them. Still, in either case, it took time for humans to build to significance; indeed, it was not for over 10,000 years after the fall of the Illithid Empire that the first human cross-world nation arose in the Material Plane.
It is only within the last two millennia that humans truly began to stake a claim as the great presence across the planes that they are today, a fact connected with the rise of the great human magocracies in the Prime: Netheril, the Suel Imperium, the Al'Malamut Empire, and so on. With many worlds' human nations reaching heights of magic within but a few centuries of one another, humans — living humans — began to spill out onto the planes in numbers previously unseen by mortal peoples, a consequence both of their sheer population and of various Lower Planar forces spreading magical techniques to humans across the Prime, hoping to gain control over the flow of petitioners through more direct contact. Ironically, the first immigration wave did not occur at the height of these magocracies, as most capable of passing through to the planes were too well off to willingly abandon their holdings at home. Instead, such immigrations were most common only at the fall of such nations, as rich and poor alike all sought to escape the devastation that always seems to come along with the fall of such a nation. Such came the massive jump in human population on the planes in the last two thousand years, and within a few generations, the establishment of the planar human race. Today, planar humans can be found everywhere from the slopes of Mount Celestia to the depths of Fire.
Coming from hundreds, even thousands, of disparate Prime cultures, planar humans have no common cultural grounds holding them together, not even a core pantheon as with most peoples; likely a result of how early they were spread across the worlds of the Prime, before even ancestral cultural touchstones could take hold in their racial memory. Though a few bearing common origin have formed expatriate neighborhoods in the various planar metropoles, such neighborhoods are largely a recent phenomenon; New Tyr in Sigil as a result of the recent Athasian emigration, for example. For the most part, they have instead assimilated themselves well into the local cultures of the multiverse, such that few could ever tell that humans had only been present in significant numbers for the last thousand years or so. Of course, as a result of this broad variability in attitude and outlook, many native planars find humans somewhat untrustworthy for their unpredictability, so varied are they that few human stereotypes have managed to take hold beyond their everpresence; at most, humans are considered by most others as a species that will go anywhere, do anything, eat anything, sleep with anything, and be anything, with no conception of cultural limitations or taboos.
Humans are a warm-blooded mammalian species, the namesake for the term "humanoid" within Planar Trade (itself a variation of the Common tongue that had arisen throughout the worlds of the Prime by the time of the first human immigration wave and quickly established itself cross-planarly as a direct result). Of the various mammalian humanoid species, humans tend to be one of the shorter-lived, reaching adulthood between the ages of 15 and 20, and with a maximum natural lifespan of less than a century; many have theorized as to what role this lesser lifespan as compared to their compatriots may have on them psychologically in terms of their focus and adaptability. Omnivorous creatures, they can sustain themselves on a wide variety of foods, though disease is still more of a risk than with some. As they lack in innate magical abilities, humans are forced to adapt to circumstances through nothing more than talent and training, adding to their reputation for adaptability and flexibility as a result. Similarly, they can seemingly thrive in any conditions, with human settlements found in nearly every corner of the planes, finding a home anywhere where life of any sort can be found. Because of this wide ranging settlement as compared with most mortals, by far the majority of planetouched out there have at least some human blood, even if not the entirety of their mortal ancestry.
Humans tend to have a wide range of appearances; though two from the same culture will tend to resemble one another, the generations spent spreading and diffusing through the planes have long since removed any such similarity within most cities and towns. Skin colors can vary from a nearly-translucent white to a deep black and everything in between. Darker hair is most common, black and brown hues, but blond and red tones are far from rare. Eyes are generally blue, green, brown, or a blend of the three, with the occasional human having two eyes of differing hues. Physically, most humans range between five and six and a half feet in height, and between 120 to 240 pounds in weight, though individuals outside this range are not unknown; in general, women tend to be shorter and lighter than men, but either can still be found in either extreme.
- Hellbound: The Blood War - The Chant of the War, pg.15
- Planewalker's Handbook, pg.76