Grave Strike(Complete Adventurer, p. 150)
Level: Cleric 1, Paladin 1,
Components: V, DF,
Casting Time: 1 swift action
Duration: 1 round
While this spell is in effect, you have a special connection to the forces of light and positive energy. For 1 round, you can deliver sneak attacks against undead as if they were not immune to sneak attacks. To attack an undead creature in this manner, you must still meet the other requirements for making a sneak attack.
This spell applies only to sneak attack damage. It gives you no ability to affect undead with critical hits, nor does it confer any special ability to overcome the damage reduction or other defenses of undead creatures.