Cosmology
Cosmology of Alshard is called Yggdrasil universe and described as the world tree Yggdrasil. Many worlds are connected by Yggdrasil like as branches and leaves of the tree. Several major worlds (including Midgard and Blue Sphere) are called "root worlds". Minor worlds and parallel universes of root worlds are called "leaf worlds". The abyss that try to change everything into void is similar to the disease of the tree that blights leaves and roots.
Yggdrasil universe includes many worlds as follow.
- Midgard - The standard stage of Alshard. The central world of Yggdrasil universe.
- Blue Sphere - The standard stage of Alshard Gaia. An alternate Earth. Although the existence of magic is concealed from public knowledge in this world, the magic-integrated technology called Alchemy is well-developed in secret.
- Another Sphere - One of the parallel worlds (leaf worlds) of the Blue Sphere. The existence of magic is well known in this world. Magic and magicians are administrated under laws by all the U.N. member countries.
- Hero's Sphere - One of the parallel worlds (leaf worlds) of the Blue Sphere. The existence of magic is disbelieved and negated in this world. All Questers are considered as superheroes.
- Sanc Crimson - One of the parallel worlds (leaf worlds) of the Blue Sphere. In this world, Jupiter became a fixed star and the homeland of mankind is Mars instead of Earth. Sanc Crimson is a garrison kingdom dominated by a cruel Queen polluted by the abyss. It invaded and annihilated five worlds already.
- Utgard - It is also treated as one of the root worlds although in fact, it is Alf's flying battleship as huge as a continent that is traveling across dimensions to avoid the abyss. Most Alfs entered into artificial hibernation in the ship.
- Hades and Helheim - Two netherworlds, Hades's inhabitants are deaths and Helheim's are demons.
- No Future - A cyberpunk world which was devastated by worldwide disasters.
- Twilight world - A fantasy world whose inhabitants have faith in the God of monotheism. The setting bears a remarkable resemblance to Blade of Arcana's.
- 10th TERRA - The world of Tenra War, Tenra bansho and Terra the Gunslinger.
- Energy planes - Several energy planes (equivalent to non-material planes) are known such as Seireikai (精霊界, lit. elemental plane?), Mugenkyou (夢幻郷, lit. dreamland?) and several Youseikyou (妖精郷, lit. fairylands?).
- Asgard - The ultimate ideal world that Questers are seeking.