Enc.: varies	IS: metal, hard	Aura:	XP: 10k	GP: 50k
Swords	-	Magic Items	-	DMG

Sword, Vorpal Weapon, is similar but superior to a sword of sharpness.

A
vorpal weapon is +3 "to hit" and for damage bonus. When a score on the
"to hit" die as shown below is made, it will sever the neck/head of its opponent:
 
 

Opponent	Modified score to sever*
normal/armored	20-23
larger than man-sized	21-23
solid metal or stone	22-23

    * Considers only the sword's bonus of +3.

The DM will note that there are many creatures that cannot suffer
decapitation due to lack or mutability of form. There are also certain
creatures that may have heads but will not necessarily be killed by
decapitation (among these are dopplegangers, elementals, and golems).
 

Question: What does “vorpal” mean?

Answer: It comes from the nonsense phrase, “and the vorpal
blade went snickersnack,” written by Lewis Carroll in Alice in
Wonderland. In the D&D® and AD&D™ rules, it is a word used to
describe an extremely sharp (magical) sword or blade. — J.
Ward, W. Niebling

Q: Must a character be of lawful
alignment to use a vorpal weapon?

A: Yes, if the sword is to be used without
penalty. As page 165 of the DMG states, all
vorpal weapons are lawfully aligned. Vorpal
weapons can, however, be good, neutral,
or evil as well as lawful.
(146.56)

Q: Is there any way to prevent a vorpal
weapon from severing the neck
if the attack roll is high enough?

A: No. However, the DM might choose to
introduce some kind of protective magic
that would do this. Note the limitations
given on page 166 of the DMG. The DM
might choose to introduce some additional
limitations; for example, it would be impossible
for a human to sever a cloud giant's neck unless the giant was bent over
or the human was flying or levitating.
(150.38)


ADQ: For the purpose of MR, 
at what level of ability does a vorpal 
sword, holy avenger, etc. operate? 
ADA: The special cutting effects of such 
weapons are NOT affected by MR. 
If the sword has INT, treat all 
spell effects (Primary Abilities & 
Extraordinary Powers) as if they were produced by 
a level of caster equal to the sword's Total 
Personality Strength (INT + EGO). 
    Special note: This equation is official. 
Though the level of caster is notably high 
by this calculation, the weapon has far 
fewer abilities than a spell-caster of comparable 
level. This extra range, duration et al. 
gained thereby (as applicable) do not 
adversely affect game balance. --EGG
(Polyhedron #25)