Trap the soul Vs. Undead

[Vexed]

The spell opening text is "Trap the soul forces a creature's life force (and its material body) into a gem."

What happens if you try to do this to a vampire? Or other undead. If they are dead then the soul has already left the body on its way to a plane. But what happens if someone casts trap the soul? Does their soul or essence get pulled back from where it went to? Does the spell fizzle because they dont have a soul?

 

[shilsen]

You're right that when a body is dead, the soul has departed. But that is not the same as when a body is undead. Sentient undead do have souls. For a specific statement on the subject, see the Magic Jar spell description. So a vampire, as in your example, would be affected by a Trap the Soul spell just as a human or other creature would.