Exorcism is a Will/H skill that allows you to expel a spirit from a person it is possessing, or a location it is haunting. This works by religious, rather than magical, means and you're at -4 if you don't have Blessed, Power Investiture or True Faith (or Divine Favour, with that book in use). The defaults are Will-6, Religious Ritual (any)-3, Ritual Magic (any)-3 or Theology (any)-3. There are no other modifiers listed, but equipment modifiers might be relevant, and Time Spent (B346) applies, although an exorcism takes quite a long time anyway. If you are taking extra time, a team effort resembling ceremonial casting (B238) could make sense, see Combining Powers from Powers p170. Using less time stacks up serious penalties. As Bill Stoddard pointed out last week, Exorcism is one of the oldest schools of healing. It presumably dates from the period when everything not utterly mundane was religious or spiritual.
Doing an exorcism takes 15 minutes x the spirit's HT, and an Exorcism roll. Critical failure requires you to roll on the Fright Check table at +10 and means you can never exorcise that spirit; failure requires you to wait a week before trying again and critical success banishes the spirit immediately. Ordinary success allows a Quick Contest of Exorcism skill vs. the better of the spirit's ST and Will; you get a bonus against a spirit possessing a creature or person of the better of the possessed's ST and Will, making the job normally much easier than exorcising a haunting. If you win, and the spirit is that of a mortal, it passes on; if it's a demon or something similar, it makes a reaction roll and flees on Poor or better, or attacks in any way it can on Bad or worse. If you fail, you can't try again for a week. In both of the failure cases, if you can make an IQ roll afterwards, you learned something about the spirit which will give you +2 against it on subsequent attempts, but you can't get a bigger bonus for further failures. I could imagine that bonus being passed on to other exorcists, for really well-known spirits, in person or in writing.
Exorcism is common on templates for religious professionals, low-tech wise folk and monster hunters. In the highly magical world of Banestorm, Exorcism has an additional -4 against demons. Dungeon Fantasy uses the skill a lot: as a primary skill for Clerics, Holy Warriors and Exorcists, a part of several power-ups, holy symbols that give bonuses, and a good deal more. Fantasy has more rules about the skill, and Horror has lots of ways to use it. Magic has the Banish ritual, which only works on extraplanar intruders. Monster Hunters has modern-day rules. Power-Ups volumes 2, 3, 6 and 7 all have examples that include Exorcism. Psis has a lot about using Exorcism to counter psionic powers. Thaumatology has a Path/Book ritual for doing exorcisms, and Urban Magics covers the spirits of mobs. Some kinds of Zombies can be exorcised, although this isn't the first thing to try.
I don't think I've ever seen this skill used in play, although it's on my to-buy list for a character aiming at True Faith, and doing this write-up has made me wonder if it might be relevant to a scenario in a campaign I'm currently playing. I've seen the Path/Book ritual used, to good effect.
How have you exercised Exorcism?
[Basic] Skill of the week: Exorcism
