Humans in the Galthamar-verse are fundamentally similar to those in the real world, and some could blend in here. Many others, however, would be noticeably different.
Sex and gender
As in reality, most humans are physically male or female, with distinctive and functionally complementary reproductive organs, though some have organs intermediate between the sex types or otherwise atypical. There are some tendencies for males and females to to differ on average in characteristics such as bone structure and body hair, though the ranges of variation for each sex are similar. Many societies have social genders based on these two sexes, but the details vary (Galthamar’s gender system can wait for another post).
Humans vary considerably in height and build. Most adults are between about four and seven feet tall. Some individuals can be shorter still; at the other extreme a few can reach two or three times the average height, or even more. There is also considerable variation from slender to robust builds. There is little difference in size or physique by sex, certainly not compared to the wide range across the whole population.
Isolated populations in unusual circumstances can have averages or ranges considerably different from the above.
Skin colours from tan to rich brown are common, with a range from near-white to near-black. For populations settled for many generations in the same climate zone, darker skin tones come to predominate in strong sun, and lighter colours in regions that see little sunlight. There is also some regional variation in how much of a reddish or yellowish tint there is to the brown. More vivid reds and yellows, and even greens, blues and other colours are possible, but rarer. Of course people travel the world, either temporarily or to stay, and so most areas have minorities, and some areas have majorities, of people with colouring reflecting their or their ancestors’ migration history more than their current habitation.
Black is the most common hair colour, with brown next, and blond or ginger hair being overall uncommon (but lighter hair often goes with paler skin and likewise is more common in less sunny climes). Again, there are rare examples of hair naturally growing in other colours, some rather vivid. Head hair may naturally grow in any fashion between tightly curled and straight, and perhaps to considerable length or fullness. The amount of overall body hair varies from very fine and short to quite conspicuous, but is generally much less than most land mammals. Among the individual variation it is possible to observe that males tend to have thicker body hair than females, and there are also regional variations in average hairiness. Some, especially males, have greater hair growth on the lower face and neck, producing beards and/or moustaches in some. Given the means to do so, humans often cut, arrange or otherwise style their head hair and (if applicable) beard, and many remove at least some facial or body hair. These stylings are a major medium for social signalling.
Eyes and faces
Brown is the most common eye colour, with grey/blue next most common – again, shades vary widely, with lighter eyes somewhat associated with lighter skin or hair and found most in less sunny climates. Vividly coloured irises are rarer – most often blue, but with green, gold, violet and others possible.
There are also many differences in the detail of facial features: wider, narrower, squarer or rounder faces; wider, narrower, longer, shorter, hooked, straight or upturned noses; the size, positioning and shape of the eyes; rounded or pointed ears of differing sizes and shapes; small or large mouths, lips and (to some extent) teeth; jutting or receding chins, etc.
Humans can even have features resembling other species, such as fur, feathers, scales, muzzle-shaped faces, horns, claws, tails, wings and so on. The resemblance may be to a specific type of animal or may be more general, and may be localized to certain parts of the body.
(I’m actually not sure how much I want to use animal characteristics in my own Galthamar campaign. I’m not sure whether it might be too fantastical or even whimsical. I may need to consult with my players as I approach bringing the world to the table. I had considered making animal characteristics rare in Galthamar proper but more common in other parts of the world that will be exotic in the campaign. But since Galthamar the continent has a significant amount of inspiration from Europe, that could seem like linking animalistic characteristics to societies based less on Europe, and that’s obviously problematic.)
Humans also vary widely in the length of life cycle. The most common life cycle sees a pregnancy of around eight to ten months, a childhood of about ten to fifteen years, an adolescence of a few more years and physical adulthood reached around fourteen to twenty-three (with perhaps a few more years for the temperament to settle down). Humans with this life cycle have a mature phase of about 20 to 30 more years, and then start to suffer slowing and weakening effects from age. Mortality rates therefore increase and, even without infection or injury, age-related death may occur from about seventy onwards. Variant life cycles do not get very much faster than this, with twelve being about the earliest humans have been known to mature physically, but there is great variation at the slower end. Some individuals can spend up to two years in the womb, with decades of childhood, a decade or more of adolescence and many decades or even a few centuries of physical vigour. It is hard to say what the upper limit to natural human lifespan is, because disease or violence tend to intervene at some point, and some may be using magic or other means to prolong their lives beyond what nature has given them.
These physical characteristics are generally hereditary, though children whose parents differ may resemble either one, or a mixture, and children may in some or all respects resemble neither parent, often explained as a throwback to some earlier ancestor, whether known or imagined.
As Galthamar ranges from mid to high southern latitudes, with low sun and short days in winter and often considerable cloud cover, colouration there is often lighter than the human average. Tan to mid-brown skin, brown and black hair, and brown eyes are common. Darker brown skin is not rare, but very dark skin is rare other than in the north, sea ports and cosmopolitan cities, where there is more migration from sunnier lands. Pale complexions, fair or ginger hair and/or light eyes are more common in the wintry south, and sometimes found in the rest of the continent.