Orcrist

)   Orcrist
Base item	elven broadsword
Damage vs. small	1d6+1d4 x2
Damage vs. large	1d6+1 x2
To-hit bonus	+1d5
Bonus versus	orcs
Weapon skill	broadsword
Size	one-handed
Affiliation	chaotic elven
When carried	(none)
When wielded	(none)
When invoked	(none)
Base price	2000 zm
Weight	70
Material	wood

Orcrist is a chaotically aligned elven broadsword. It is one of two artifacts in the game that can be created by #name-ing them, along with Sting. To do so type in #name, select a normal elven broadsword, and name it Orcrist. To make sure you did it correctly, you may now try to name the sword into something completely different—all artifacts resist naming. The Orcrist gives a +d5 to hit and double damage against all orcs. Orcrist can also be given as a gift by sacrificing.

Encyclopedia entry

The Great Goblin gave a truly awful howl of rage when he
looked at it, and all his soldiers gnashed their teeth,
clashed their shields, and stamped.  They knew the sword at
once.  It had killed hundreds of goblins in its time, when
the fair elves of Gondolin hunted them in the hills or did
battle before their walls.  They had called it Orcrist,
Goblin-cleaver, but the goblins called it simply Biter.
They hated it and hated worse any one that carried it.
        [ The Hobbit, by J.R.R. Tolkien ]

History

In Hack 1.0 and Hack 1.0.1, any weapon can be named Orcrist and do extra damage against orcs; there can even be more than one Orcrist.

Hack 1.0.2 restricted this advantage to two-handed swords. Other weapons could still be named Orcrist, but would do no extra damage.

Orcrist became an elven broadsword in NetHack 3.1.0.