Few Questions

[Luna_Mayflower]

1. So, one of the groups I DM were going up against a squad of Vampire Spawn. One player, who's character is a Barbarian, asked if they could shoot the undead through the hearts with small stakes from her crossbow. I kind of dismissed it, saying that she'd have to get a natural 20 or so to be that accurate at a decent distance. She 20'd the roll. So, since I'd said she could on a 20, she instant killed one of the spawn. Next attack, she 20'd again. My question is: Does shooting a Vampire Spawn in the heart with a stake work?

2. I'm home brewing a nasty devil assassin in the campaign, and, while I'm probably going to base it off some demon or devil, the main feature of the creature is that it can cast Dimension Door, at will, as a free action. Anyway, I'm thinking, since it will be able to pop around in battle and sneak attack a lot, that maybe the target of it's 'port attack should get a spot check to see it poping in behind them and negating the sneak attack. Does this sound fair and good? And what kind of DC would you think for the spot check? (Party level 7th)

[Urpriest]

1. Technically, shooting it in the heart with a stake would work, but the rules don't say whether a) stakes are aerodynamic enough to use as crossbow bolts or b) whether it's possible to target that well. So I'd go with whichever interpretation seems the most fun here, the rules don't really hold you back one way or the other. Note that if you remove the stake the vampire comes back to life.

2. Dimension Door won't let it sneak attack in the first place, so that's not an issue. Your turn ends after using Dimension Door, and even if it didn't the ability just isn't that fast. You'd need some other ability to make it do that, and at that point it's a matter of whether the new ability you're adding is balanced. Note as well that most devils and demons get either Dimension Door or Greater Teleport at-will anyway.

[Yora]

With dimension door and teleport, the demon could move into hiding places somewhere nearby and since the PCs wouldn't know where he went, he could make a new Hide check, since he isn't being observed. Then on his next turn the following round, he could sneak up on a PC again.

[Nettlekid]

Seconding everything Urpriest said, because he knows what's up.

I'd also agree that shooting a stake through the Vampire Spawn's heart should suffice to kill it, and if the player got two nat 20s to do so, then the fate of the dice surely agreed. Perhaps there's no way it would be accurate enough without a nat 20.

As for the warping fiend, perhaps you could have it under a persisted/permanent Fiendish Quickening effect (spell from BoVD), or an evil version of Quickshift (which Fiendish Quickening basically is). Or give it some kind of prereq-waived Sun School feat or Shadow Pounce (maybe a bit too strong) to let it attack if it teleports right next to its target.

[Yora]

A babau happens to be an assassin demon with Sneak attack and greater teleport at will.

[Kuulvheysoon]

If we're descending into Homebrew-esque territory, maybe give it Inconstant Location 3/day as a Psi-like Ability? Lets it flit around through line of sight as a swift action once per round (and not causing any AoOs). Give it some sort of concealment (maybe in total magical darkness, which devils have no problem with) to make them flat-footed?

[Menzath]

Normally you can't just pew pew stakes. they are not arrow dynamic and would no fit onto a bow or crossbow. And notice that it has to be a stake, not some wooden arrows or whatnot.

Most of the time to "Stake" a (un)living creature someone has to succeed on a pin while another person "stakes" said pinned creature.
But something being helpless means you do not have to pin(it can't resist so what is the point?).

Maybe you could throw them, but they would do damage like a small dagger and have maybe half a daggers range increment, and yeah I would rule that said stakes could "crit" on nat 20's(with a confirmation roll) to stake one.