The black dragon, D, is a monster that appears in NetHack. It has a younger form in the baby black dragon, D. The black dragon has disintegration resistance both intrinsically and from its scales, and its breath weapon fires rays of disintegration. It is the only guaranteed source of disintegration resistance in the game.
Players will not see baby black dragons through normal random monster creation outside of the Oracle and Sokoban levels; adult black dragons start appearing around the midway depths of the dungeon. Black dragons can be generated in throne rooms as early as dungeon level 15, and may appear when a throne at this depth or lower is looted. Black dragons can be created if a chaotic spellcaster casts the summon nasties monster spell.
Taking on a black dragon is an especially perilous endeavor - the ray can only be protected against either through reflection or disintegration resistance, and the latter is most easily obtained by either eating black dragon meat or wearing its scales. If a dragon's blast of disintegration hits a monster, including you, that is neither resistant nor reflecting, it destroys objects in the following order:
- Any worn shield.
- Any worn body armor, including cloaks.
- A worn amulet of life saving; this only applies in corner cases where a living monster wearing an amulet has been polymorphed into a form the amulet would not work on. Otherwise, it functions as normal.
- The victim in question. The rebound can still disintegrate the target if their gear saved them from the direct hit.
This makes the black dragon incredibly dangerous to engage at any non-melee distance within its line-of-fire, especially in unlit areas such as Fort Ludios. While it thankfully lacks any other resistances, care still has to be taken during combat - players who lack a source of reflection should avoid being caught down the hall from one. The breath weapon can be avoided either by trying to lure it close, or else using (very) fast speed in order to close the gap while avoiding the line of fire as much as possible. Eating black dragon meat or obtaining its scales ensures that disintegration will no longer be an issue for you during the rest of that game unless the property is lost, though you will still want to keep pets from being reduced to ash if possible.
The black dragon is often sought out as a pet, or more frequently used as a polyform, in order to dispatch particularly nasty foes who otherwise lack disintegration resistance. A Monk not doing polyselfless can use the form of a black dragon to evaporate Master Kaen without him reaching striking distance; Samurai can use the pet or polyform to engage and kill Ashikaga Takauji without risk of death by bisection (especially since dragons are too large to be instakilled this way). Disintegrating a quest nemesis will not destroy the quest artifact or the Bell of Opening.
NetHack 2.3e introduces the black dragon along with all of the other modern dragon types (and their breath weapons) except for silver. In this version, Black dragonbreath instakills the player, and there is no means of reflection, disintegration resistance, or amulet of life saving - the temptation of genocide must be balanced with the fact that dragons of any color are a guaranteed source of fire resistance, which is absolutely necessary to enter Hell; there is no means to genocide only black dragons.
NetHack 3.0.0 introduces baby black dragons alongside the other baby dragons. This version also distinguishes all color dragons, their younger stages and their corpses, and introduces dragon scale mail. In addition, reflection is now available and black dragon breath is toned down slightly; it also becomes possible to genocide only black dragons, ensuring that sources of fire resistance remained.
NetHack 3.1.0 introduces black dragon scales along with the other colors, as well as the current method of obtaining dragon scale mail.
Variants of NetHack often subject dragons to extensive changes, including the black dragon.
In the biodiversity patch, the black dragon is renamed to the sirrush.
As with all other dragons in SLASH'EM, baby black dragons have a base level of 4 instead of 12, and can be encountered via random generation in ordinary levels with a frequency of 2; they are also eligible for creation on many levels that generate random D on level creation. Adult black dragons have a base level of 18 instead of 15.
Baby black dragons hit as a +1 weapon, and adult black dragons hit as a +3 weapon. Adult black dragons have a chance to turn traitor while tame.
In the West the dragon was the natural enemy of man. Although
preferring to live in bleak and desolate regions, whenever it
was seen among men it left in its wake a trail of destruction
and disease. Yet any attempt to slay this beast was a perilous
undertaking. For the dragon's assailant had to contend
not only with clouds of sulphurous fumes pouring from its fire
breathing nostrils, but also with the thrashings of its tail,
the most deadly part of its serpent-like body.
"One whom the dragons will speak with," he said, "that is a
dragonlord, or at least that is the center of the matter. It's
not a trick of mastering the dragons, as most people think.
Dragons have no masters. The question is always the same, with
a dragon: will he talk to you or will he eat you? If you can
count upon his doing the former, and not doing the latter, why
then you're a dragonlord."