Vorpal Blade

)   Vorpal Blade
Base item	long sword
Damage vs. small	1d8 +1
Damage vs. large	1d12 +1
To-hit bonus	+1d5
Bonus versus	(any)
Weapon skill	long sword
Size	one-handed
Affiliation	neutral
When carried	(none)
When wielded	beheading
When invoked	(none)
Base price	4000 zm
Weight	40
Material	iron

The Vorpal Blade is a very useful artifact weapon. It is a neutral long sword, and has a 5% chance of instantaneously killing monsters by beheading. It is shunned by some players because it only does +1 damage and d5 to-hit, but others find the insta-kill to be quite useful. The beheading only works on monsters with heads.

The Vorpal Blade originally appears in the poem Jabberwocky by Lewis Carroll. In the poem, an unnamed adventurer "took his vorpal sword" in hand and sought the dangerous Jabberwock:

"One, two! One, two! And through and through

The vorpal blade went snicker-snack!

He left it dead, and with its head

He went galumphing back."

The implication is that the vorpal blade beheaded the Jabberwock. Because of the origin of this weapon, in NetHack it has a 100% chance to behead Jabberwocks.

Instakill probability table

The following table summarizes the damage done by the Vorpal Blade. For example, after you hit a monster ten times, there is a 40% change that you have beheaded it. You have also done an average of 55 points of physical damage to it. The odds of beheading a monster rise above 50% after 14 hits, at which point you have damaged the monster for approximately 77 points anyway.

Hits	Cumulated instakill probability	Physical damage to small monsters (avg)	Physical damage to large monsters (avg)
1	5%	2–9 (6)	2–13 (8)
2	9.75%	4–18 (11)	4–26 (15)
3	14.26%	6–27 (17)	6–39 (23)
4	18%	8–36 (22)	8–52 (30)
5	22.6%	10–45 (28)	10–65 (38)
10	40%	20–90 (55)	20–130 (75)
15	53.7%	30–135 (83)	30–195 (113)
45	90%	90–405 (248)	90–585 (338)