Okay I created a house rule thread with Scion's rule (I hope you don't mind) and my own clutzy ideas 

KarinsDad said:So then, which magical defense protects against Vorpal?
So fortification would negate the burst from a shocking or flaming burst weapon?Hypersmurf said:If you're immune to crits, the crit still happens; you just don't take the extra damage. Crit-triggered effects - like Vorpal, Flaming Burst, etc - still trigger and have their normal effect.
If you have a % chance of negating the crit, and that chance arises, the crit never actually happened. Crit-triggered effects remain quiescent, because the critical that would trigger them was negated.
Not necessarily. Although I cannot think of one off hand (unless certain types of vermin, perhaps?) that can survive a beheading and are not immune to critical hits, I would rule in this case that they are beheaded and receive critical hit damage. This is, in my opinion, what happens when Vorpal is applied to undead, golems, etc. The beheading and the damage occur, but the damage is negated by immunity to critical damage.Nail said:And if the beheading weren't dependent on confirming a critical hit - a hit that has been negated by the Fortification property - I'd agree with you.
That is to say: The "two events" of which you speak are not simultaneous and independent. Beheading is dependent on the critical hit.
Scion said:High AC? Miss chance? Mirror Image?
All of those help to protect against it.
Changing into a form without a head works as well.. and i suppose there is something to be said for creatures who have heads out of reach.
mvincent said:So fortification would negate the burst from a shocking or flaming burst weapon?
KarinsDad said:At the level at which Vorpal swords come into play, high AC, miss chance, and Mirror Image might not be very viable options. Many characters, even Fighters, have ways to acquire True Seeing, See Invisible, etc. at those types of levels.
If you were the PC Cleric and you were about to fight the BBEG, wouldn't you put a True Seeing spell on the PC Fighter with the Vorpal weapon?
And typically, you do not change into a form with no head unless you know ahead of time that you will be facing a Vorpal weapon.
KarinsDad said:Basically, some minor defenses do exist (even Fly), but only Fortification can really be considered a defense purposely designed to counter Vorpal (and other special weapon / ability attacks).
HydraNyeshet said:I cannot think of one off hand (unless certain types of vermin, perhaps?) that can survive a beheading and are not immune to critical hits,
Scion said:But the wording on vorpal and fortification say that one does not effect the other.
Scion said:So, it could be that vorpal has no direct counter in the ruleset other than being immune directly. There are other items like that, but none that I can think of kill instantly.
More reason I think vorpal should be removed completely.
Even if fortification did work I still would think vorpal should be removed. It just isnt balanced when used.
So you are saying a "critical hit effect" does not follow from a "confirmed critical hit"?Scion said:I see them as seperate and distinct, given the wording. It definately does not say that it is a critical hit effect, merely that the critical that it already is must be confirmed for it to trigger.....