Wikipedia
Glorantha is a fantasy world created by Greg Stafford. It was first introduced in the board game White Bear and Red Moon (1975) by Chaosium, and thereafter in a number of other board, roleplaying and computer games, including RuneQuest and HeroQuest, as well as several works of fiction and the computer strategy game King of Dragon Pass. The Gloranthan world is characterised by its complex use of mythology, heavily influenced by the universalist approaches of Joseph Campbell and Mircea Eliade, its Howardian ethos, its long and distinctive history as a setting for role-playing games, its community development and expansion, and (unusual among early American fantasy role-playing games) its relative lack of Tolkienesque influence.
Stafford began imagining Glorantha in 1966 as a way to deepen his own understanding of mythology. He founded the company Chaosium to publish the board wargame White Bear and Red Moon in 1974 (other sources say 1975), which was set in Glorantha. Chaosium later published other games in the setting, including the critically acclaimed RuneQuest. Various later editions of RuneQuest, the narrative role-playing game HeroQuest (the first edition of which was published as Hero Wars), and the video game King of Dragon Pass were also set in Glorantha, as were several prominent fan efforts. Stafford has also explored the Gloranthan setting in the fantasy novel King of Sartar and a number of unfinished works published under the collective name of "the Stafford Library".
In Glorantha, magic operates from the everyday level of prayers and charms to the creation and maintenance of the world. Heroes make their way in the world, and may also venture into metaphysical realms to gain knowledge and power, at the risk of body and soul. In the more recent material competing magical outlooks, such as theism, shamanism and mysticism, exist to explain the world. Within each metaphysical system, adherents may also compete - such as when theistic worshipers of rival gods battle each other. The world is flat, with a dome-like sky, and it has been shaped in large and small ways by the mythic actions of the gods. The 'historical' world of Glorantha is in a more or less fallen state, having recovered only partially from a universal battle against Chaos in the mythic Godtime.
Humans are the dominant race, but other sentient beings abound. Some, such as the mystic dragonewts, are unique to Glorantha. Familiar nonhuman races, such as elves and dwarves, are distinct from their common, Tolkienesque portrayals.