The Realm of Atlos
The Weave works to protect the world from the dangers of unrefined magic while giving the ability to cast spells to magic users.
It was created after an inexperienced spellcaster accidentally opened a portal to another realm, allowing Tiamat to enter the previously godless world of Atlos and inciting a terrible war for supremacy among the gods.
Destroying the Weave would result in widespread destruction. Reckless use of magic can also damage the Weave, creating areas of dead or wild magic where normal spellcasting doesn’t work.
The Weave is present in everything, being literally woven into the building blocks of existence. It was created by Mystra, goddess of magic, who actively wills its effects. When spellcasters abuse magic, Mystra can cut off the spellcaster’s ability to use magic. She also keeps a part of The Weave within her body, guarding it from those who seek to control or destroy it.