Magic jar

The magic jar spell enables the caster to shift his life force into a special receptacle (a gem or large crystal). From there the caster can force an exchange of life forces between the receptacle and another creature, thus enabling the wizard to take over and control the body of another creature, while the life force of the host is confined in the receptacle. The special life force receptacle must be within spell range of the wizard's body at the time of spellcasting. The wizard's life force shifts into the receptacle in the round in which the casting is completed, allowing no other actions.

While in the magic jar, the caster can sense and attack any life force within a certain radius; however, the exact creature types and relative physical positions cannot be determined. In a group of life forces, the caster can sense a difference of power and can determine whether a life force is positive or negative energy.

An attempt to take over a host body is blocked by a protection from evil spell or similar ward. Its chance of success is based on the mental prowess of the subject. If successful, the caster's life force occupies the host body and the host's life force is confined in the magic jar receptacle. The caster can call upon rudimentary or instinctive knowledge of the subject creature, but not upon its real or acquired knowledge (i.e., the wizard does not automatically know the language or spells of the creature). The caster retains his own knowledge and intellect. If the host body is human or humanoid, and the necessary spell components are available, the wizard can even use his memorized spells. The host body retains its own physical abilities and properties.

The caster can shift freely from the host to the receptacle if within the spell's range. The spell ends when the wizard shifts from the jar to his own body.

A successful dispel magic spell cast on the host can drive the caster of the magic jar spell back into the receptacle, while one cast against the receptacle forces the occupant back into his own body. If the wizard who cast the magic jar is forced back into his own body, the spell ends.

If the host body is slain, the caster returns to the receptacle, if within range, and the life force of the host departs (i.e., it is dead). If the host body is slain beyond the range of the spell, both the host and the caster die. Any life force with nowhere to go is treated as slain unless recalled by a raise dead, resurrection, or similar spell. If the body of the caster is slain, his life force survives if it is in either the receptacle or the host. If the receptacle is destroyed while the caster's life force occupies it, the caster is irrevocably slain.

Note: This version of magic jar originally appeared in the 2nd Edition Player's Handbook for Advanced Dungeons & Dragons from TSR. Its use here is for the purposes of providing context for the campaign only.