Dark aura was a divine magic spell available to priests of Cyric, the Mad God. It surrounded the caster with a gloomy atmosphere that greatly improved the caster's combat ability and, to a lesser extent, that of all evil-aligned creatures within the vicinity. At the same time, it hindered the combat ability of good-aligned creatures.
This spell lasted for seven minutes and had a spherical radius of 70 ft (21 m) centered on the caster. More experienced casters could extend the duration and the radius of effect. The dark aura was a noticeable dimness, similar to a partial eclipse (vision was not impaired, there was just less light) that enveloped the caster and all within the area of effect. Those that were evil in alignment felt a slight improvement in their combat abilities. Those that were of good alignment felt the weight of menace on them and had their combat prowess degraded by a similar amount. Beings that were neutral on the good/evil spectrum were completely unaffected by this spell. The caster received three times the boost that other evil creatures gained to combat actions.
Good-aligned creatures within the dark aura had to continually resist the spell and, if successful, were spared the sapping of their combat abilities for one minute. As a side-effect, all good-aligned creatures within the dim sphere were outlined with a glow that indicated their lawful/neutral/chaotic alignment. Lawful creatures glowed amber, neutral creatures glowed orange, and chaotic creatures glowed a bright red. This alignment-aura did no harm except possibly giving away their position if they were hiding. The dark aura penetrated obstacles like walls and floors out to the limit of its radius.
This spell did not require any concentration after casting was complete so the caster was free to cast other spells. For the duration of dark aura, the bonuses on the caster stacked with other spells or could otherwise be taken into account where applicable.
Only verbal and somatic components were required to cast this spell.