Shiram
The Underdark of the Realms is suffused with a magical radiation the drow call shiram. A remnant of the mighty forces that shaped the terrain of the Underdark, shiram distorts and interferes with certain types of magic. Currently there are three major impacts of shiram on magic.
* Despite the absence of all sunlight, moonlight, and starlight,
the Underdark is darker than logic would suggest. A permanent
effect of shiram is a magical darkness throughout the area.
* Scry checks made on a target located with the Underdark fail
because of the magical radiation.
* Transmutation spells and effects such as teleportation do not
work reliably. Currently teleportation will fail in the Underdark
due to the interferences of shiram.