D&Dtools1

You can selectively destroy, alter, or implant memories in the target creature as you see fit.
Casting the spell gives you access to all of the subject's thoughts and memories, allowing you to implement as many of the following specific effects as you like.
Memory Erasure: Any or all memories possessed by the subject can be erased, including knowledge of specific events, people, or places.
Memory Implant: You can create false memories in the subject's mind as you see fit.
Memories of being friends with a hated enemy, events that didn't really take place, or betrayals by people the subject regards as friends could all be implanted.
Negative Levels: You can bestow a number of negative levels equal to 1/2 the subject's character level or less.
This effect represents erasure of class knowledge and training.
These negative levels never become permanent level loss, but they cannot be removed by spells such as restoration,
remaining in effect as long as the subject is under the effect of this spell.
Persona Rebuilding: By erasing the subject's previous personality and implanting a false set of memories, you can build a new persona for the creature, altering its alignment, beliefs, values, and personality traits.
Some class abilities are affected by alignment changes.
Programmed Trigger: You can program the subject to delay the onset of any of the above effects until a specific event takes place, such as the receipt of a coded message, capture by enemies, or arrival at some destination.
Similarly, you could specify some or all of the alterations you create in a subject to be removed by a specific event.
The nature of programmed amnesia is such that a subject given new memories (whether willing or not) might be given cause to suspect that those memories are false, based on how complete your programming is.
For example, a paladin subject to a persona rebuilding that changes her alignment to neutral loses her paladin abilities.
Unless you impart a specific believable memory of why she changed alignment, the character will perceive this unexplained gap in her memory and might take steps (such as seeking a magical cure for her "amnesia") that could negate the spell's effect (see below).
Generally, your subject must be either willing to undergo the spell or restrained in some way so that it cannot leave or interfere with the casting.
Programmed amnesia is normally permanent unless you care to specify events that will end the effect.
Its effect can also be removed by a greater restoration or wish spell.
Material Component: A set of small crystal lenses set in gold loops worth 500 gp.