Wards of Silverymoon

The wards of Silverymoon were a pair of magical protections that utilized a mythal that protected Silverymoon from all sorts of threats.

Area
The first ward encompassed an area that surrounded the city as well as beyond the city wall, while the second worked in concert with the first and provided further protections to the palace.

Effects
Full details of the mythal's effects, including the effects of the second ward, were known to only two people, the High Mage of Silverymoon and the ruler of the city, but a few others were trusted enough to be allowed to attune themselves to the wards and be able to control most of their powers.

The first ward prevented any evil and death magics from being cast as well as any portals from being constructed. Demons, devils, dragons, drow, duergar, giants, goblinoids, mind flayers, orcs, and trolls of evil intent were magically compelled to leave the city and never return. All creatures within the boundary of the mythal were also unable to become invisible, always knew when they were being scryed upon and were protected from negative energy and evil.

One of the effects of these wards was that temperatures inside the city remained comfortably high year-round and prevented the natural formation of ice. Whenever heavy snowfall occured they would repel snow from the city, as if Silverymoon were covered by a dome, redirecting it to the nearby River Rauvin.

Those who carried a ward token were exempt from the following additional effects:
 * Prohibition from casting evocation spells that created fire.
 * Prohibition from casting teleportation magic.
 * Prohibition from summoning things.

The few trusted enough to be allowed to control certain aspects of the mythal gained the ability to cast certain spells with a simple command word whenever they wanted to within the bounds of the mythal.

History
After the Spellplague of 1385 DR, the wards of Silverymoon were greatly weakened, eventually dissipating entirely. However, splinters of the power created by the mythal remained and empowered the abilities of the Spellguard.

Silverymoon's Mythal was thought lost during the Spellplague, but it was merely dormant within the Moonbridge. With Mystra's Return, the mythal of Silverymoon blossomed out of the Moonbridge in all its former glory.