Beheading and bisection
Beheading is a property that appears in NetHack, and is solely associated with Vorpal Blade; it is defined by SPFX_BEHEAD.
Contents
Description
When a monster (including you) is hit with Vorpal Blade, there is a 5% chance that Vorpal Blade will behead the victim - this deals HP damage equal to twice their maximum HP, and thus is technically not considered an instadeath. A player polymorphed into a monster with a head will die and be returned to their base form.[1]
This chance does not change if the target monster has a headless form: the sword will instead "miss <foo> wildly", dealing no damage. If the target is unsolid, the sword may slice "harmlessly" through its neck, and is treated as a normal hit. If Vorpal Blade hits a jabberwock (including a player in the form of one), it will always behead them.[2]
As implied by a comment in the code, how many heads the monster actually has (e.g. ettins and their zombie/mummy forms) is ignored - so long as it meets the above conditions, Vorpal Blade can behead and kill it.
Despite its name, the vorpal jabberwock that is deferred in vanilla NetHack does not have any beheading attacks, and is simply a tougher jabberwock.
Variants
In addition to Vorpal Blade retaining its usual traits in variants of NetHack, vorpal is an object property for weapons that is rarely encountered in some variants.
Most variants that implement the vorpal jabberwock often give its claw attacks the ability to behead monsters that it hits, and also make it so that Vorpal Blade always decapitates them as with normal jabberwocks.
SLASH'EM
In SLASH'EM, Vorpal Blade beheads foes 10% of the time instead of 5%, making it considerably more powerful. A similar weapon, Thiefbane, has a 10% chance of beheading any @. The vorpal jabberwock will not be instantly beheaded by Vorpal Blade, and has the same 10% chance as any other monster.
The potion of invulnerability does not protect you from beheading, since it only prevents standard HP loss.
GruntHack
GruntHack has the "vorpal" object property, which can only occur with bladed weapons. Single-handed weapons with the vorpal property function the same as Vorpal Blade, beheading solid non-headless targets with a 5% chance and always beheading jabberwocks. A two-handed vorpal weapon will instead bisect enemies as The Tsurugi of Muramasa does, with a 5% chance of instakilling small creatures or of cutting deeply into large creatures.
GruntHack also implements the vorpal jabberwock and gives this property to its two claw attacks.
UnNetHack
UnNetHack makes use of the vorpal jabberwock and gives its claw attacks the ability to behead targets, though the chance is halved to 2.5%.
dNetHack
dNetHack also has the vorpal object property, though it functions differently: the vorpal type is chosen based on the object's damage types, and vorpal weapons that are both slashing and piercing will decapitate the target. The chance of decapitation is 5%, as in vanilla NetHack; decapitation will also damage and potentially destroy that monster's helm, based on its AC value (and regardless of whether or not that helm would actually be caught in a beheading blow).
In addition, dNetHack introduces several new artifacts capable of decapitation:
- Release from Care and Crescent Blade can behead their targets, with the same chance as Vorpal Blade.
- The Lifehunt Scythe will only behead targets while sneak-attacking with it, with the normal 5% chance per hit.
- The Dragon's Heart-Stone can behead monsters that are not aware of your location.
- Snickersnee and The Kusanagi no Tsurugi are capable of beheading monsters.
- Levistus's Shadowlock can behead its target.
DynaHack and FIQHack
In DynaHack, the vorpal property functions the same as in GruntHack, except that it no longer occurs on randomly generated objects. The same is true in FIQHack.
EvilHack
In EvilHack, Cerberus is made immune to instadeath in this manner: if beheaded, he will instantly grow a new head in its place before the other two can be removed. EvilHack also uses the deferred vorpal jabberwock, which has decapitating claw attacks and behaves very similarly to GruntHack's version of the monster.
