Bane

The Banes are a group of artifact weapons, notable in that they do double damage to a specific group of monsters. They are generally considered to be worthless for most purposes, since they reduce the probability of receiving a more useful artifact. Despite its name, Magicbane is not included, for a couple of reasons: it has no double damage bonus, and it is actually useful. Likewise, Fire and Frost Brand are not included, because they are actually useful.

Demonbane

This lawful long sword deals double damage against all demons, as well as has +d5 to hit them. The Demonbane does not do any better than a regular long sword against the Riders, the mail daemon, sandestins, or djinni. Its utility or lack thereof depends on your opinion of the difficulty of most demons.

Dragonbane

This unaligned broadsword deals double damage against all dragons, as well as has +d5 to hit them.

Giantslayer

This neutral long sword does +d5 to hit and double damage against all H, giant mummies, zombies, but not ettins or titans.

Ogresmasher

This unaligned war hammer confers +d5 to hit and double damage against ogres.

Sting

This chaotic elven dagger provides +d5 to hit, and does double damage to orcs and no other species; it will do its damage to orc mummies and zombies, though. It also provides the warning intrinsic against orcs, and cuts through spider-webs.

Sunsword

This lawful long sword does double damage to all undead creatures; that's L, M, W, Z, ghosts, and shades. It is made slightly more useful by the fact that it's a light source, with a radius of 2, and that it prevents blinding from light-based sources. Again, the keep-or-toss decision is based on how much you hate undead.

Orcrist

Big brother to Sting, this elven broadsword is chaotically aligned, and gives a +d5 to hit and double damage only against orcs. Sting and Orcrist may be created by #naming a single elven dagger or broadsword.

Trollsbane

This unaligned morning star does double damage to all T, troll mummies, and troll zombies, and +d5 to-hit.

Werebane

This is an unaligned silver saber. It does double damage against all were-creatures as well as +d5 to hit. However, it is slightly more useful than the other banes in that when wielded, it protects you from lycanthropy.

Puddingbane

Not an actual artifact, but merely a nickname for a thoroughly rusted -7 orcish dagger (dip one a few times and engrave with it), which can be used to split puddings for farming without killing them, even with high strength.