L^: mu5	-	R#: (1")*	-	D^: S
C^: v.s.m	-	CT: 1r	-	S^: S
A^: One creature	-		-	MP: 7, 80

Effect: Magic jar is a very unusual spell.

It enables the magic-user to take over the mind of the victim and thus control the creature's body.
In fact, if the body is human or humanoid, the magic-user can even use the spells he or she knows.
The possessor can call upon rudimentary knowledge of the possessed,
    but not upon the real knowledge, i.e. a possessor will not know the language or spells of the possessed.

A. The spell caster transfers his or her life force to a special container (a large gem or crystal),
and from this magic jar the life force can sense and attack any creature within the spell range radius,
but what the creature is, is not determinable from the magic jar.
The special life force receptacle must be within spell range of the magic-user's body at the time of spell casting.

B. Possession takes place only if the victim fails to make the required saving throw.
Failure to possess a victim leaves the life force of the magic-user in the magic jar.
Possession attempts require 1 round each.

If the body of the spell caster is destroyed, the life force in the magic jar is not harmed.
If the magic jar is destroyed, the life force is snuffed out.
Returning to the real body requires 1 round, and can only be done from a magic jar in spell range of the body.

Saving Throw: Possession takes place only if the victim fails to make the required saving throw.
Failure to possess a victim leaves the life force of the magic-user in the magic jar.

The saving throw versus a magic jar spell is modified by comparing combined intelligence and wisdom scores
(intelligence only in non-human or non-humanoid creatures) of the magic-user and victim.
 

Difference	Die Adjustment
Negative 9 or +	*R*, +4
Negative 8 to 6	*R*, +3
Negative 5 to 3	*R*, +2
Negative 2 to 0	*R*, +1
Positive 1 to 4	*R*, 0
Positive 5 to 8	*T*, -1
Positive 9 to 12	*D*, -2
Positive 13+	*W*, -3

A negative score indicates the magic-user has a lower score than does his or her intended victim;
    thus, the victim has a saving throw bonus.

*R* Note that a possessed creature with any negative difference or a positive difference less than 5
is entitled to a saving throw each round to determine if it is able to displace the possessor's mind,
*T* a positive difference of 5 to 8 gains a saving throw each turn,
*D* a positive difference of 9 to 12 gains a saving throw each day,
*W* and a positive difference of 13 or better gains a saving throw each week.

If the magic jarred creature regains control of its mind,
the magic-user is trapped until he or she can take over the mind for control or escape.

MC: The "magic jar" (a special container : a large gem or crystal) is the spell's material component.

Quote:
Originally Posted by Gray Mouser

So, my questions are these:

1) What happens when someone is possessed? Should I just treat the effect as a "Magic Jar" spell?

Yes, that is basically what happens to the possessed individual.

Quote:
Originally Posted by Gray Mouser
4) The DMG mentions that a "Protection from Possession" scroll works even for dead bodies. I'm assuming that a possessed dead body would be animated and function under the influence of said possessing creature (and be able to be turned by a Cleric as a "special" on the turning table).

your assumption regarding dead bodies, and animals for that matter, is correct. they can be turned by clerics as "special." I'd vary chances depending on the strength of the possessing entity, but all will be difficult to turn.
 

Quote:
Originally Posted by Gray Mouser
5) Just out of curiosity, would you think it owuld be possible to possess an intelligent sword since it has its own poersonality?

No, the sword is possessed by a spirit.
that spirit would have to be dislodged/destroyed, and then the possessing entity would be stuck in the weapon...not a desirable thing for any demon or devil.