James Y.’s necromancer class uses harvested souls as fuel for necromancy spells. From the post:
Last Breath must be collected at the moment of a creature’s death and is usually stored in glass vials.
I like the flavor of this mechanic, and the way it interacts with the encumbrance system (by using flasks for storage). It would be interesting to use something like this as a more general resource. Here is a simple idea along those lines.
After death, souls linger for a short time before moving to the next phase. Conveniently for game purposes, this period is about ten minutes (which is to say, one exploration turn). A magician may spend this time collecting a soul if an empty flask is at hand. Do not neglect to roll for random encounters. Soul capture requires reciting minor incantations and performing the proper ritual gestures. At the end of this time, a soul is captured. Flasks, empty or occupied, are significant for purposes of encumbrance. No more than one soul may be stored per flask.
Such trapped souls have a number of different uses, including:
- Casting a prepared spell without expending it (called “drinking a soul”).
- Animation of an object (chair, broom, sword, corpse, etc) for one exploration turn.
- Feeding undead (like how rations or livestock work for living monsters).
Using the soul in any of these ways negates its existence and destroys it utterly. Some claim that this is an abhorrent act, but certain groups of magicians have developed entire philosophies around the liberation of the souls bound to the reality through eternal recurrence. Sages have remarked that such philosophies are convenient for the earthly needs of magicians, but do not entirely discount the validity of such beliefs.
Bottled souls may also be traded between magicians or otherworldly beings.
Postscript: believe it or not, I totally wrote and scheduled this post before I started playing Dark Souls recently!