This necklace has a small ruby gem with a silver wire twisting and meeting a blue gem on the opposite side of the pendant.  This necklace allows the attuned to guarantee critical damage for a level 1 single target spell but will deal half of the extra possible damage to themselves. (A level one spell that deals 1d10 damage will deal 2d10 but the caster loses 5 health.) The attuned caster may use this item a number of times equal to their proficiency level.

Notes: Spell Caster