How is HD determined in Animate Dead?

Question

I have a dread necromancer playing in my game and I've been wondering if we're interpreting the Animate Dead spell correctly. Since the player isn't one to review the rules of spells herself, I've been leaving it up to the most experienced player to keep track of how their spells work (saves me the headache of digging through the Spell Compendium as well).

We've been running it by the most experienced player's interpretation, which is that when she casts Animate Dead, she can choose how much HD to give it, based on the spell components and the limits of controllable HD.

But after she raised and beefed up some creatures past their normal HD limits, I reviewed the spell description and now I'm beginning to wonder if the HD for the created skeleton or zombies based on the creature's original HD?

It sounds like the spell description could be read either way.

Answer 1

The HD for the created skeleton or zombies is based off the creature's original HD. When the template is applied to a creature, you use the creature's HD (minus any class levels) and raise them to d12s. From the SRD entry for Skeleton:

Drop any Hit Dice gained from class levels (to a minimum of 1) and raise remaining Hit Dice to d12s.

So, for example, a 9th level necromancer is looking at the corpses of three 6HD trolls. The necromancer is capable of animating 18HD worth of skeletons with a single casting. The necromancer cannot animate one of the trolls as an 18HD troll skeleton, nor can she animate a 16HD troll skeleton and a 2HD troll skeleton. She can, however, animate three 6HD troll skeletons.