Spidercloak armor

Spidercloak armor was an arcane conjuration spell, used in the Underdark, which surrounded the caster in a dark network of magic shadows and non-sticking webs.

Effects
The magical dark network acted as a barrier to both physical and magical attacks. Whilst under effect of the spell, the caster's armor would be raised significantly, and could become strengthened over time, as it fluctuated.

The spell also cloaked the caster's alignment aura, such that another spellcasters couldn't tell whether they were good, or evil. Any other magical auras were also cloaked.

Components
As well as a verbal and somatic component, the material component could be either a spider web part or a living spider itself. The living spider would be crushed to death in the process.

Appearances

 * Computer games:
 *  Menzoberranzan