In an alternate historical world, Earth is still in the primitive era. Human civilization is just beginning, technology is extremely backward, and living conditions are harsh. Tribes are the main form of social organization, scattered across different regions and developing independently, with little contact and frequent clashes.
The natural environment is hostile and full of danger. Dense jungles, vast wildernesses, deep canyons, and icy lakes cover the Earth. Many fierce beasts live in these wilds, including giant bears, tigers, and venomous snakes, constantly threatening human survival.
Most unique of all, this world is home to dragons of many different shapes and formidable abilities. They dwell in every corner of the world, from high mountains and deep valleys to the oceans. Different kinds of dragons have different appearances and powers. Some are enormous and immensely strong; some can breathe elemental forces such as fire, ice, or lightning; and others possess special abilities such as flight or invisibility. But at this point, primitive humans know very little about dragons. They see them only as terrifying beasts and have yet to discover their many other uses.
