The most powerful arcane magic (such as that used by the Dragon) completely drains an area of plant and animal life. These dead magic locales have nothing left to give.
Effect: A creature in a square of dead magic takes a -5 penalty to the attack roll of any arcane or primal attack power. The arcane defiling power cannot be used in squares of dead magic.
Usage: Dead magic defiled terrain should be used sparingly, even more so when the adventuring party includes arcane and primal heroes. It takes an extremely powerful defiler (such as a sorcerer-king) to so thoroughly eradicate all life in an area.
Published in Dark Sun Creature Catalog, page(s) 135.