Are there limitations/cautions to "Vorpal"?

Question

I want to give one of my good characters a vorpal Dwarven Ax. My first thought is about alignment issues. I realize that it's how it's actually wielded that would cause alignment conflicts, but is it necessarily "good" to be chopping people's heads off, when another less dramatic and disrespectful form of death will do?

Additionally, I want to know if there are any, and what limitations should be enforced. If my character is up against an enemy 2-3 size categories larger, would the vorpal magic be enough to finish the job? Does the character need to physically jump up to the height of the neck? What if the neck is thicker in diameter, than the total length of the blade of the ax?

Answer 1

Alignment

I would say, no. In general, killing vs. not killing is more of an alignment concern than how you kill them.

Some deities might be interpretable as being against vorpal. And characters at the very lawful end of the spectrum might have issues. But ultimately this is a DM/player call. It isn't an assumption of the setting.

(Personally, I'd recommend against alignment restrictions here, except perhaps for the most holier-than-though cleric or paladin. Vorpal is a marquee ability in the game, and as a player I'd be disappointed to have it locked away from me)

Beheading

The thing to remember here is that vorpal weapons are magical. Spectacularly magical. About as magical as it's possible for a weapon to be. Exactly HOW the beheading occurs isn't specified (perhaps the size of the weapon's cutting edge is enhanced by magical energy, allowing for the severing of distant or large necks). All that really matters is that if you can hit it, you can trigger vorpal.

Answer 2

Alignment

I can think of many more sadistic ways to kill someone than beheading them (the chaotic player characters in my games seem to be very good at inventing new ones!). Decapitation is messy, but not inherently evil. I agree with @AceCalhoon that this is much more of a cultural thing: samurai, for example, are lawful (Complete Warrior, page 9) but if Kurosawa's films are anything to go by, they have no moral qualms with severing their opponent's limbs.

Other Limitations/Gotchas

The description specifically mentions that oozes, constructs and undead (other than vampires) are immune to vorpal weapons.

I would think that a beheaded vampire would assume gaseous form as if it had dropped to 0 hit points, although the wording in the DMG is ambiguous.

Plants and elementals are immune to critical hits, but does that make them immune to vorpal weapons? This would seem to be up to DM discretion. Swarms should certainly be immune.

The description also says that an aberration is immune to vorpal weapons if it has no head, even though it is otherwise subject to critical hits.

Magically fortified armor protects against critical hits and sneak attacks (DMG p219). I think it is up to DM discretion whether this armor would also provide protection against vorpal weapons.

Answer 3

A point that might be relevant is that beheading has at various points in history been considered a relatively pleasant death. Sure, it's messy, but it involves no pain below the neck, and more importantly, is over pretty quickly.

Realistically, fatal battle wounds could include ruptured organs, internal bleeding, effectively unstaunchable blood loss and other such trifles, all of which would lead to long, agonising deaths. Compared to that, beheading is mercy. In fact, that's why the guillotine was important during the French revolution: It 'democratised' execution by making the beheading penalty available to everyone.

D&D stylises death and injury a great deal: A character dropped to negative hit points will typically die in under a minute unless stabilised, since dying in agony over a period of hours doesn't generally fit well with the 'heroic fantasy' theme. Still, unless the player characters are in the habit of bandaging up fallen foes, a quick end would still be more merciful than 1-9 rounds of bleeding out.

Also, adding to the "It's Cultural" argument, in at least one D&D setting I could name, vorpal weapons were widely used by the unquestionably evil Yugoloth. Make of that what you will.

Answer 4

There is no alignment restriction on vorpal blades

The other answers already covered that beheading is not inherently more good or evil than killing in some other instant way, like splitting the skull or stabbing through the heart; and that it is up to you how you narrate the effect against large creatures.

The rules for 3.5e also do not impose any alignment requirements on Vorpal weapons.

I'm mostly adding an answer to point out that historically, this was not always the case. When Gary Gygax originally introduced vorpal swords to the game in the Greyhawk Supplement, they required the wielder to be lawful to use, and performed best in the hands of a (mandatory lawful good back then) paladin, here from the weapon description:

it will perform in the hands of any Lawful fighter, although it requires a Paladin in order to act in its anti-magic capacity

That means, in the games historic context, a vorpal axe is actually a great fit for a good (and, as a dwarf likely also lawful) character.