Ars Magica GRIMOIRE

Cruciatus Curse (Perdo Corpus 20)

R: Voice, D: Concentration, T: Individual
This spell causes the target excruciating pain, and he must make a Stamina + Size roll against an Ease Factor of 9 to be able to do anything but writhe in agony. Enduring Constitution adds 3 to the Stamina roll; other Virtues, Flaws, or Abilities that affect the ability to endure pain may also modify the roll as appropriate.

(Base 5, +2 Voice, +1 Concentration)

(three pages of vetting over in the Cruciatus for ArM thread)