To be fair, Larian show precious thin understanding of creature lore in the D&D setting. If they think that stabbing Astarion with wood while you're talking to him should have any kind of effect on him beyond ruining his jacket, then it becomes hard to have much faith that they'll understand any of the more involved nuances of fiendish divisions and ancestry.
Lol. SO true, Niara. SO true.
I actually had to look up vampire spawn because I was like, "something's not right. BG2 made you enter the crypts where the vampires and spawn were, and you had to stake them in their coffins."
I'm not big on vampires, so I usually don't do a lot with them. I admittedly wasn't super familiar with the whole vampire spawn stats, etc. After reading up on them, I was like, "Can they not read? Do they read the lore and just disregard it? Seriously?"
"While incapacitated in its resting place.". That's when a stake kills them.
But then, Astarion isn't really a Vampire spawn in any major way, is he? He bleeds and dies like anyone else, so why shouldn't a stake through the heart kill him. It'd kill Gale or Lae'zel. Astarion isn't really different from them in game, is he?