Magic

= The Weave = The Weave, controlled by Mystra, is a way through which raw magic is accessed, tapped into and used by casters of magic, both knowingly and unknowingly. The Weave is the way in which magic presents itself to beings for their use, and it flows throughout the world, touching almost every corner of existence, with exception of dead-magic zones.

In the years after the Spellplague, the term Weave also became a synonym of the use of magic.

Manifestation
The Weave is considered many things, including Mystra's body, the source of magic, all the studies of casters, arcane and divine alike, and the many energies and forces that exist around the planes. Many see it as a "fabric" on which magic is "drawn", and damaging the fabric causes magic to go awry. Some textbooks deliberately falsify the nature of the Weave, as an attempt to limit the knowledge associated with spellcasting. Casting a spell is equivalent to telling the Weave to rearrange itself to create an effect.

The Weave was also linked to fate, and a rare few individuals could manipulate such connection to alter the future to their advantage. However, usually the Weave punished those who used "her" in such way.

Spellplague
Because Mystra (and formerly Mystryl) was inextricably bound to the Weave (one cannot exist without the other), when Mystra was assassinated by Cyric and Shar, the Weave collapsed and initiated the Spellplague. Henceforth it presented itself as scraps of burning crystal tumbling through an endless void. With the death of Mystra, Shar collapsed as well.

it was revealed that Mystra foresaw her own fall and let it happen because the Weave was growing more and more unstable, and needed to be renewed as part of a cycle fated to repeat again and again.

Anomalies
Places such as dead-magic zones or wild magic zones were places where the Weave had been damaged or was non-existent.

Wild magic zones
In wild magic zones, a spell could backfire upon its caster, target the wrong location, be dramatically increased in power, or many other things. A wild magic zone and its parameters could be detected using a detect magic spell. A caster could temporarily fix a wild magic zone with any dispel or permanently fix it using a wish spell.

Cosmic disasters like the Time of Troubles caused the emergence of severe wild magic zones after the Weave was heavily damaged. After the Time of Troubles, most wild magic zone disappeared but some remained.

Another source of wild magic zones were the artificial distortions of the Weave called mythals. Apart from decay due to neglected maintenance, events such as the Fall of Netheril or the Time of Troubles damaged them. The damage turned these corrupted mythals into - even by wild magic standards - unpredictable wild magic zones.

Dead magic zones
Dead magic zones were places where the Weave was no longer in existence. Both it and its boundaries could be detected in the same way a wild magic zone could, but from outside the zone. Unlike wild magic zones, most casters innately knew when they've stepped into a dead magic zone. A dead magic zone could only be fixed with a wish spell.