In this multiverse, there exists one singular law. The "Law of Souls" states: "A soul must be present for any being to exist." A person CANNOT exist without their soul. This fact is known to, and accepted by the world. The "Law of Souls" is the singular rule of this multiverse. However, as all rules...it was meant to eventually be broken....

The world lives by this rule. It has shaped each and every life. Towns, Cities, Kingdoms, and the world (or even worlds), have built their whole society around the existence of souls.

Academies around each world train talented individuals in the use of their soul. Souls themselves manifest in, usually, one of two ways. Through magic, or through something physical, be it a weapon or an enhancement. Extremely talented and gifted individuals are capable of using both. These trained people venture off into the world, some are lost to crime, others are picked up by various insignificant kingdoms, and the rest? Well, they become adventurers. Doing whatever menial tasks they can for money.

"Each and every being has a soul." Well, this doesn't exclude anything, even animals. They are restricted to the same type of soul manifestation as humanoids. However, extremely powerful and advanced beasts gain a sort of intelligence. Sometimes these creatures can form a dungeon, of sorts. Adventurers explore and conquer these dungeons in an attempt to minimize the damage these intelligent beasts cause world-wide.

Humans and beasts are not the only race to walk along the ground, however. Elves, Dwarves, Giants, Insectoids, Avians, and even Aquatic or semi-aquatic humanoids have formed their own Cities and/or kingdoms, but even so, their cultures all follow the "Law of Souls".