When a wizard casts Energy Drain, he drains 2 levels of experience from the target victim.
In-game description Edit
|“|| Energy Drain|
The casting of this spell opens a channel between the caster's plane and the Negative Energy Plane. The caster of the spell acts as a conduit between the two planes, sucking life from a victim and transferring it to the Negative Energy Plane, draining the target of 2 levels of experience. The target of this spell loses Hit Dice, Hit Points, and abilities permanently. These levels can only be restored by a priest's Restoration spell.