Spell: Dead Light

Scroll sold at the Savant tavern in Clerkburg, Greyhawk City

Dead Light

Conjuration (creation)

Level: Sorcerer 5, Wizard 5

BoXM: Wizard 10

Components: S, M (a dead firefly which has been preserved in a solution 

     made from mushroom powder, saffron, and fat)

Casting Time: 1 standard action

Range: Close (25 ft. + 5 ft./2 levels)

Effect: Shining mote of light

Duration: 10 minutes/level

Saving Throw: None

Spell Resistance: No

Source: The Mage's Tower website

You hold a dead firefly in your hand and as you concentrate, it dissolves into nothingness. Nearby, in a place of your choosing, a mote of light which can only be seen by arcane means appears.

This spell creates a mote of light whose radiance illuminates a 30 feet radius but which is only visible by arcane means such as arcane eye, arcane sight, greater arcane sight, or true seeing. To all others, there is no visible effect. You can move the mote at the beginning of your turn as you desire, forward or back, up  ordown, straight or around corners, up to 60 feet per round. This is a free action. You may also direct it to hover near you at a set distance and it will move as you do, within the limitations of its own speed.

The mote is both invisible and incorporeal and can pass through objects and nonmagical barriers. It partially illuminates hidden (10 + your caster level + either your Intelligence [for wizards] or Charisma [for sorcerers] modifier is added to your Perception check against an opponent attempting to hide within the area illuminated by the dead light) objects and creatures. Ethereal and invisible beings and items become visible (by arcane means) as insubtantial outlines. Ethereal creatures remain unreachable from the Material Plane (except with force effects), but any incorporeal or invisible creature illuminated by the dead light does not benefit from concealment, and so attacks against them suffer no miss chance.

The mote cannot be attacked or damaged, though dispel magic and similar spells can dispel it. The mote winks out if the distance between you and it exceeds the spell's range.

This spell may be cast in conjunction with glowing orb. When this is done, all of its effects become a part of the magical light source produced by that spell. If the glass sphere of the glowing orb is destroyed, the mote of dead light also ends. Casting this spell in conjunction with glowing orb produces a magical controllable light that lasts for one day per level of the caster (instead of the permanent light source glowing orb usually produces). 

The spell effect produced by casting glowing orb and dead light together may be made permanent via the permanency spell.

GM NOTE

This spell is considered unique in its rarity; it is thought that 3 or perhaps 4 copies of it exit in spellbooks through the Flanaess.

The BoXM entry is for players playing in the Arcane Age of Greyhawk campaign. It is based on Monte Cook's Book of Experimental Magic. I cannot recommend it enough.