[3.5] Vampires and Vampire Spawn

[kpenguin]

From the SRD:

Fast Healing (Ex)

A vampire heals 5 points of damage each round so long as it has at least 1 hit point. If reduced to 0 hit points in combat, it automatically assumes gaseous form and attempts to escape. It must reach its coffin home within 2 hours or be utterly destroyed. (It can travel up to nine miles in 2 hours.) Any additional damage dealt to a vampire forced into gaseous form has no effect. Once at rest in its coffin, a vampire is helpless. It regains 1 hit point after 1 hour, then is no longer helpless and resumes healing at the rate of 5 hit points per round.

By "if reduced to 0 hit points in combat", does this mean exactly zero or zero or less? Also, once it is in its coffin and helpless, does this mean further damage can kill it without causing it to become gas again or is this just so people can stake it?

Also, from the SRD:

Fast Healing (Ex)

A vampire spawn heals 2 points of damage each round so long as it has at least 1 hit point. If reduced to 0 hit points in combat, it automatically assumes gaseous form and attempts to escape. It must reach its coffin home within 2 hours or be utterly destroyed. (It can travel up to nine miles in 2 hours.) Once at rest in its coffin, it is helpless. It regains 1 hit point after 1 hour, then is no longer helpless and resumes healing at the rate of 2 hit points per round.

The vampire spawn appears to lack a full vampire's invulnerability to damage when forced into gaseous form. Is this a mistake? If not, then does an attack while in gaseous form kill the vampire spawn?

[Biffoniacus_Furiou]

Undead reduced to 0 HP (or lower) are destroyed/killed, unlike living opponents who die at -10. A vampire (spawn) reduced to 0 HP or lower, i.e. if they would be destroyed like other opponents reduced to a fatally low HP total, they instead assume gaseous form and attempt to escape. Any additional damage after that point is irrelevant, they're not destroyed by HP damage, only by one of the described methods.

[kpenguin]

Undead reduced to 0 HP (or lower) are destroyed/killed, unlike living opponents who die at -10. A vampire (spawn) reduced to 0 HP or lower, i.e. if they would be destroyed like other opponents reduced to a fatally low HP total, they instead assume gaseous form and attempt to escape. Any additional damage after that point is irrelevant, they're not destroyed by HP damage, only by one of the described methods.

Nothing in the abilities says that, though. That's the point of my question.

If they were only going to be destroyed by a certain method, they would have been given regeneration, not fast healing.

[Biffoniacus_Furiou]

Creatures with no Con score cannot ever have Regeneration.

Vampire Weaknesses

For all their power, vampires have a number of weaknesses.
Repelling a Vampire

Vampires cannot tolerate the strong odor of garlic and will not enter an area laced with it. Similarly, they recoil from a mirror or a strongly presented holy symbol. These things don’t harm the vampire—they merely keep it at bay. A recoiling vampire must stay at least 5 feet away from a creature holding the mirror or holy symbol and cannot touch or make melee attacks against the creature holding the item for the rest of the encounter. Holding a vampire at bay takes a standard action.

Vampires are also unable to cross running water, although they can be carried over it while resting in their coffins or aboard a ship.

They are utterly unable to enter a home or other building unless invited in by someone with the authority to do so. They may freely enter public places, since these are by definition open to all.
Slaying a Vampire

Reducing a vampire’s hit points to 0 or lower incapacitates it but doesn’t always destroy it (see the note on fast healing). However, certain attacks can slay vampires. Exposing any vampire to direct sunlight disorients it: It can take only a single move action or attack action and is destroyed utterly in the next round if it cannot escape. Similarly, immersing a vampire in running water robs it of one-third of its hit points each round until it is destroyed at the end of the third round of immersion. Driving a wooden stake through a vampire’s heart instantly slays the monster. However, it returns to life if the stake is removed, unless the body is destroyed. A popular tactic is to cut off the creature’s head and fill its mouth with holy wafers (or their equivalent).

[Prometheus]

Undead are also immune to nonlethal damage, which makes it confusing (at least to me) how it would apply anyway.

The entry of the vampire does make it quite clear that what a vampire has is better than what a living creature with regeneration has (for one, it gets to fly away instead of being knocked out, for another, there is no limit to the hp damage).

[Tsotha-lanti]

Nothing in the abilities says that, though. That's the point of my question.

It's a logical conclusion.

Undead are destroyed at 0 hp. At 0 hp, however, vampires change into gaseous form and fly away. It's obvious that further damage is irrelevant, because they are already at 0 hp and weren't destroyed.

[JonestheSpy]

On a logistical level, it would seem to be an almost useless-ability if a vampire had to be reduced to exactly 0 HP to turn gaseous and fly away, but not if reduced to -1 or less.