Once the gods of madness claimed such a domain, they began spreading their madness-related blessings to their followers. Though the Dismal Caverns were shared with other beings and deities, Ghaunadaur spent his time there alone, letting insanity creep up on him. In his madness, he released many abominations that carried madness to whatever plane they arrived on. Cyric, the Mad God, was an everlasting void of mania and instability. His insanity grew indefinitely, sometimes seeming to bring him back to what might be sanity, thus cementing his mind in the depth of his madness. Mortals wanted to keep Tharizdun's very name from their minds out of pure fear. His followers were inclined to take extreme actions and suffer much inner torment, as their god existed to bring about the end of everything.
Any divine caster that worshiped a god that claimed the madness domain could channel its powers. Divine casters who chose to channel the madness domain were more skilled at deception. When a caster that was aligned with the madness domain used an ability that harmed an enemy, their channelling of the domain could cause their target to become less accurate for a short period of time. The powers of this domain were known as enfeebling strike, overwhelming strike, righteous brand, and visions of blood.
Striking with fearful power, the deity's madness could also strike a worshiper's target, sending it into a quick turn of insanity and making it hit itself. Once a day, a devoted spellcaster could gain the clarity of madness and become more wise or strong willed.
Novice spellcasters were able to use (lesser) confusion, touch of madness, and rage. Clerics of some experience could cast confusion, bolts of bedevilment, and phantasmal killer. Those that were masters of this domain had access to insanity, maddening scream, and weird.
- Logan Bonner (August, 2009). “Domains in Eberron and the Forgotten Realms”. In Chris Youngs ed. Dragon #378 (Wizards of the Coast), pp. 25–38.
- Rob Heinsoo, Richard Baker, Logan Bonner, Robert J. Schwalb (July 2009). Divine Power. (Wizards of the Coast), p. 116. ISBN 978-0-7869-4982-3.
- David Noonan (May 2004). Complete Divine. (Wizards of the Coast), pp. 139–140. ISBN 0-7869-3272-4.