View source for Revised Necromancer Handbook (3.5e Guide)/Unusual Rules

====A note on Undead Creation with a Rod of Undead Mastery====
Remember that undead creation is an instant effect that only checks your “max HD controlled” when you cast the spell, meaning you can cast the spell with the rod, then put down the rod to go to sleep and you won’t have to worry about undead becoming uncontrolled. You can pull similar tricks with temporary bonuses to your caster level, such as with Deathknell.