History
While there are a large number of different and widely varying cultures taken from Earth, there are a few similarities between them. First and formost among them is the experience of being uprooted from their home world and thrown into a war zone, surrounded and hated by hordes of creatures from the worst nightmares. Elves, orks, fey, walking rat-men and more were wrapped in a genocidal war of unimaginable proportions. In general, it was the humans that were able to stick together and present a united, militant front to the world were the ones who managed to survive.

The early years of humans on Lithgar saw many humans die, more enslaved and nearly everyone driven from their point of origin. MORE HERE

Biology
The human digestive tract contains strong acids that are capable of breaking down an immense range of organic materials. This allows them to eat nearly anything and obtain sustenance from roots, weeds, leaves, bark and the like. The need for vitamins and minerals remains the same so a varied diet is still necessary, but that diet may be made up of things that are not usually thought of as food.

The more fundamental the diet the more inefficient it is, and while an human in a forest can never starve to death he will spend the majority of his time foraging. Just because they *can* eat anything doesn't mean they enjoy it or get much much energy from it. Cultivated crops are much more palatable and efficient, and animal protein the best.

As a secondary benefit, humans are resistant to many ingested poisons, but this only applies to things that stay in the stomach and can be digested. Things like poisons absorbed in the mouth, liquids that pass quickly into the intestines and mineral-based poisons such as arsenic are unaffected and take effect normally. A mildly disturbing effect is immunity to botulism, allowing humans to eat spoiled meat. It still looks and tastes disgusting, but it won’t kill you and you won’t starve.

The same applies to the major herbivores brought from Earth, such as horses, cattle, pigs, chickens, sheep and goats. While carnivores have this ability they cannot take advantage to best effect and many of them have died out, and likewise omnivores (rats in particular) have not experienced the explosive population growth that an unlimited food supply would allow.

One of the practical upshots of this is that human societies are capable of surviving and thriving where other races would starve. While they cannot live in barren deserts or wind-blown rocky mountains, if there is sufficient plant life there can be humans. When they first came to Lithgar, humans moved (fled) to the far reaches of the world, established themselves and over time expanded to compete for the more agricultural lands.

Human Animals
Human livestock grants an impressive source of meat, milk and eggs in virtually any climate, as well as war steeds that do not require any special grains. These animals have allowed various human settlements to survive in places where other races would starve.

Their animals would not have remained a unique human advantage for long, except for the differences in body chemistry between humans and the native races. As with elves, humans have a "not-native" scent that makes inter-species disguise impossible, and apparently the natives have a "not-Human" smell that offends Earth animals. None of them will willingly remain in a native settlement, and if forced into captivity they will gradually stop eating - ultimately sickening and dying. Warhorses are especially violently opposed to being ridden by any of the native races. Elves can ride Earth horses but view them with distain - if the average elf needs a steed he'll either cast a spell and create one, or go to his family stables and saddle up a gryphon.

Half-humans
As with elf-native halfbreeds, there are a few recorded elf-human hybrids. These have also required magical intervention but are much more mentally stable. Half-elves are extremely rare (i.e. you'd have to have a very good background story) and get the worst of both worlds: natives and humans treat them as elves, and elves treat them as freaks. Perhaps because of this, the few half-elves that are known to have survived to adulthood are remarkable individuals, both physically powerful and magically talented.

Magical Ability
Humans are well attuned to the forces of magic, producing a suprisingly high number of low-level spellcasters relative to their population. Women have a small but noticable advantage, making up 5 of every 9 mages, and there is no correlation between gender and raw magical power. The relative proliferation of low-power mages is significant in in harvest, healing, disease control and child mortality.

Gender Equality
The dietary adaptation, in combination with the ability of magic to reduce infant mortality, lessens the pressure on women to be nothing more than baby factories. The fact that there are more women throwing spells than men enhances this concept. Things are often not all that much above the “women are property” view, but there is much more acceptance of women who reject their traditional roles and take up an independent or traditionally masculine profession. This does, of course, depend on the society in question – for example, the Middle Kingdoms are still very prejudiced.