Bones

In NetHack, a bones level (also known as a bones file or simply bones) refers to a level that is saved when the player character dies, which may be loaded in place of a normal level in some future game. Only one bones file is stored per dungeon level: it has a ¹⁄₃ chance of being loaded in place of a standard map for that level, and will otherwise remain untouched.

Traps in early dungeon levels can feature "fake bones" that emulate actual bones files.

Generation

If a character dies on an eligible dungeon level, they have a $\frac{\lfloor \frac{depth}{4} \rfloor}{\lfloor \frac{depth}{4} \rfloor + 1}$ chance of leaving bones, where D is equivalent to the depth of that level. In practice, this means that a bones file is never created or loaded above dungeon level 4. It is also entirely possible for a bones level to be saved as bones again if it is loaded as an eligible level by another character who is then killed on that level - in rare cases, players may encounter a triple or even quadruple bones.

Assuming that the level in question is eligible, the odds of a bones file being created can be expressed as inversely proportional to the equation floor(depth/4) + 1 - there is a ¹⁄₂ chance of bones being created at dungeon levels 4-7, a ²⁄₃ chance of bones being created at levels 8-11, a ³⁄₄ chance of bones being created on DL 12-15, a ⁴⁄₅ chance of bones being created on DL 16-19, and so on.

In addition to dungeon levels 1-3, the other following levels are ineligible to create bones files on:

• Any level with dungeon branch stairs or a magic portal (including a level that has a portal in a Fake Wizard's Tower)
• The first level of the Gnomish Mines, if it is created on DL 3.
• Mines' End
• Sokoban
• The home and goal levels of the Quest
• Fort Ludios
• Medusa's Island
• The Castle
• The top and bottom floors of Vlad's Tower
• The top and bottom floors of The Wizard's Tower
• The vibrating square level
• Moloch's Sanctum
• Any of the Elemental Planes, including the Astral Plane

The same levels are ineligible to load bones files on, minus the Gnomish Mines if it appears on DL 3.

Bones files created in eligible special levels such as Minetown may be loaded as a different depth, and are generally exceptions to ad-hoc rules regarding dungeon generation (e.g. "no polymorph traps above dungeon level 8").

Fake bones

As mentioned above, "fake bones" can be generated on traps in early dungeon levels: a trap that is lethal in some manner will generate a pre-aged corpse along with some cursed objects atop the pile, and traps that generate and/or shoot objects will have at least a few of those objects among the pile.

Description

A bones level will contain some remnant of the former player character - this is determined at the time of death, and is usually a named ghost paired with an appropriate corpse, though other monsters and/or objects can be left behind depending on the monster who killed them:

• If the character was killed by any V (vampire, vampire lord, or Vlad the Impaler), a named regular vampire replaces the ghost.
• If the character was killed by any W (wraith, barrow wight, or Nazgul), a named regular wraith replaces the ghost.
• If the character was killed by a ghoul, the ghost is replaced with a named ghoul.
• If the character was killed by a mummy, the ghost is replaced with a mummy of the appropriate race (human mummy, elf mummy, etc.) bearing the late character's name and holding their inventory - they will also be generated with a mummy wrapping if they do not already possess one.
• If the character was killed or petrified by a cockatrice or chickatrice, a statue of the character containing their inventory is left instead of a monster and/or corpse.
• If the character was killed by sliming, the ghost is replaced with a named green slime.

If the cause of death does not leave behind a statue or a mummy, a headstone will be generated on the spot where the character was killed, with any monster that represents the former player character generated asleep atop it; every item in the former character's inventory will be placed atop the headstone, along with their corpse if applicable. A character that dies and leaves behind a statue will instead have their inventory made into the statue's contents.

The level will also be saved in the state it was in at the time of their death, with some exceptions:

• The invocation items and the Amulet of Yendor are always replaced with mundane equivalents:
  • The Amulet is replaced by a cursed cheap plastic imitation of the Amulet of Yendor.
  • The Candelabrum of Invocation is replaced by a cursed, partly-used and unlit wax candle.
  • The Bell of Opening is replaced by a cursed bell.
  • The Book of the Dead is replaced by a cursed spellbook of blank paper.
• Former pets will become hostile.
• The following monsters will not be present:
  • Medusa
  • the Wizard of Yendor
  • Vlad the Impaler
  • your quest nemesis
  • your quest leader
• Corpses of unique monsters are exchanged for doppelganger corpses, and their statues will be animated as doppelgangers in the guise of those monsters - tins of unique monsters will be made empty.

A character that loads a bones level will always have their quest artifact and any other artifact that was already created in their game replaced with their regular base items - for example, a character that has generated Stormbringer and loads a bones level where the former character had Stormbringer will find a runesword in their bones pile instead. All artifacts that are not replaced will revert to their base alignment, e.g. the Mitre of Holiness in bones is always lawful, even if found in the bones of a chaotic priest. Every other item in the former character's inventory has a ⁴⁄₅ chance each of being cursed outright, and with the above exceptions will otherwise retain their original beatitude; individual and per-type item names are cleared, with the exception of the nameable fruit.

Bones files locations

On the Windows port, the data for a bones file is stored in the playground directory. As the filename contains clues to where the player died, it is trivial to identify potential bones levels. The file is created when a character dies on a bones-capable level, and is deleted when a bones level is reached and incorporated into an active game - if the character later dies on a bones-capable level, the file may be re-created with the appropriate filename. A player observing the files within the playground can notice when a suitable level is coming up and spot if bones are loaded for that level.

The file naming format used is "bon<branch><role>.<level>" - for example, "bonM0.T" is a bones file for Minetown. The file itself is not meant to be human-readable. The characters used in the filename are defined in dungeon.def:

• <branch> is one of:
  • D – Dungeons of Doom
  • M – Gnomish Mines
  • G – Gehennom
  • T – Vlad's Tower
  • Q – Quest
• <role>:
  • Is normally "0", if part of the normal dungeon
  • Changes to represent role-specific quest branches, e.g. "Bar" for Barbarian quest, "Wiz" for Wizard quest, etc.
• <level> is one of:
  • Numbers 1 through 53 – these correspond to ordinary levels that are eligible for leaving bones. This number is offset from the first of the branch appropriate—e.g. if the bones are on the second level of the mines, the filename would be "bonM0.2".
  • O – Oracle (if <branch> is "D", as the Oracle can only be in the Dungeons of Doom and Orcus Town shares "O")
  • T – Minetown
  • R – Rogue level
  • V – Valley of the Dead
  • A – Asmodeus' Lair
  • B – Baalzebub's Lair
  • J – Juiblex's Swamp
  • O – Orcus Town (if <branch> is "G", as Orcus Town can only be in Gehennom and the Oracle shares "O")
  • X – Wizard's Tower

Wizard mode

In wizard mode, you will be prompted when you reach a bones level with the message "Get bones? [yn] (n)", allowing you to selectively retrieve the bones file for that level. You'll also get the prompt "Unlink bones? [yn] (n)". Selecting y removes that bones file from the possible set of bones files for normal games.

When you die on a bones-suitable level, you will be presented with the opportunity to "Save bones? [yn] (n)", allowing you to selectively save bones files. If there was already a bones file for that level (i.e. you said "no" to getting bones when entering a level) you will also be prompted with "Bones file already exists. Replace? [yn] (n)", allowing you to selectively overwrite the bones file for that level.

Strategy

Bones levels can be a double-edged sword: the bones pile they contain will have all the dead adventurer's possessions, including several valuable additions to bolster a character's current kit, but a majority of those items will be cursed - it is usually a bad idea to quaff, read, wield, or wear anything from a bones pile until its beatitude has been properly identified. The bones pile may also contain several artifacts: this also includes typically-unwanted ones, and any amount of artifacts will increase the count for that game and make future wishes for artifacts more difficult. The level will also contain most of the monsters present at the time of the character's death, most likely including the one that killed the previous character; if that monster has dangerous armor, weapons, wands, and/or other items, it is also very likely to use them against the current character that discovered it.

A ghost or other similar monster created on top of the bones pile can prevent monsters from gaining access to the former character's inventory until it is woken up and moves off the pile, keeping dangerous items out of their hands until you can get to them; conversely, a bones wraith or vampire that is woken up will immediately try to pick up and equip what they can to use against a character. It is a good idea to turn off autopickup temporarily before stepping onto the bones pile, in order to prevent sudden and accidental encumbrance while sorting through its contents; stealth may also be worthwhile for keeping the bones monster asleep until you can determine an ideal approach. If a headstone is generated under a bones pile, Elbereth cannot be engraved to keep away monsters, though a scroll of scare monster (including an existing one in the pile) will deter most of them.

Cursed bags

A bag in a bones pile may potentially be a cursed bag of holding, though there is the possibility of it merely being the sack of a former Rogue or Archeologist - see the section below on forensics for more details on determining bones contents by role. It is generally unwise to loot such a bag unless it is conclusively known to not be a cursed bag of holding, as this risks destroying valuable contents. A bag that places an unencumbered character at stressed encumbrance or worse is likely to be a cursed bag of holding, with higher encumbrance from the bag signifying better odds - even then, this is not always a certainty, e.g. the former character may have engaged in packrat behavior, or else been killed in the midst of transporting a stash.

If you confirm a cursed bag of holding and manage to get it into your inventory, and are not encumbered enough that you cannot act, you can use a scroll of remove curse, the spell of remove curse or a potion of holy water to uncurse it - if not, you can move aside items you do not want cancelled and zap a wand of cancellation at it, which sets a container's beatitude to uncursed without affecting the contents. As a last resort, you can #tip it onto the ground to try and preserve most of the contents.

Forensics

There are various observable signs that a character has found a bones level, in rough order of likelihood:

• The presence of fruit with a different name from yours is often a dead giveaway.
  • As type-naming fruit is a free action, a character that is about to die may rename their fruit to inform the next character that finds the level of their demise - engravings can also work for this purpose, though they are most effective when done ahead of time and without using a resource that may otherwise aid in survival. A character can only engrave a maximum of eight characters per turn, which limits their final vocabulary to phrases like "purple h", "GWTWOD", or "Archon".
• Abnormal monster presence (or lack thereof):
  • Detecting any named monster - particularly a named former pet, a ghost with a non-standard name, and/or is any of the other bones-eligible monsters listed above - is frequently a telltale sign.
  • Large concentrations of different monsters can signify a read cursed scroll of create monster, as well as possibly repeated castings of summon nasties on later floors.
  • Partially or completely empty special rooms, such as throne rooms, zoos or leprechaun halls.
  • A ghost outside of a graveyard, especially with a non-default name - note that this may also be the result of a monster quaffing a milky potion. A few special levels (e.g. Asmodeus' Lair) also generate a random ghost when they are created.
  • Out-of-depth or non-random monster generation, e.g. an Archon or a water demon on DL 4.
  • Wounded monsters can signal combat occurring prior to the character's death, and can be identified with a stethoscope - but note that ordinary traps can also wound monsters.
• Unusual item placement:
  • Few to no items lying on the floor.
  • Items that are not usually generated, such as disarmed bear traps.
  • Piles of items related to specific monsters, such as a collection of quarterstaves or leather armor for golems, or noticeable piles of racial equipment - this also typically indicates that some level of combat occurred prior to the character's death.
  • Chests and other containers with abnormal contents, such as weapons and armor.
  • The presence of corpses, which are only generated at level creation in the Valley of the Dead, Orcish Town, behind niches (sometimes marked with iron bars), and atop traps on the first four levels of the dungeon. Of note is that corpses may also be left if monsters are killed by traps before you encounter either.
• Non-random engravings.
• Broken doors (can be identified with far look).
• Unusual holes in walls - these may be created by a tunneling monster, especially if there are tunnels containing rocks nearby.

When encountering a bones level, it can be advantageous to know some details of the deceased character: for example, if a bones pile has a quarterstaff, a randomly named cloak, two spellbooks, and a magic marker, you can be fairly certain the corpse is that of an early wizard, from which you can deduce that the cloak is a cloak of magic resistance. This method comes with no guarantees, but the more "indicator items" you find, the more certain you can be.

Below is a list of each role's "indicator items":

Class	is indicated by
Archeologist	bullwhip, fedora, tinning kit
Barbarian	two-handed sword, battle-axe
Caveman	club, sling, large number of rocks and/or flint stones
Healer	scalpel, stethoscope
Knight	lance, many apples and carrots, saddle (possibly on a still-live pony or other steed)
Monk	many apples and oranges, a robe
Priest	4 potions of water, mace and robe
Ranger	two large stacks of arrows
Rogue	large stack of daggers, sack, lock pick
Samurai	large stack of ya (bamboo arrows), katana and short sword
Tourist	Hawaiian shirt, expensive camera, credit card, stack of 4 scrolls
Valkyrie	long sword, small shield, dagger
Wizard	quarterstaff, randomly named cloak, two spellbooks, two rings, a few scrolls and potions, one wand

Rogues and Valkyries are among the hardest to identify, since they both start with items that are either common to other roles or commonly generated. A +3 small shield almost certainly used to belong to a Valkyrie, but requires identification or wearing to reveal the enchantment.

Ethics

From a game design point of view, bones are potentially unbalancing, and a few players object to using bones items for this reason - finding one's own bones is an even more difficult position. Luckily, on a public server there are enough players that this is unlikely to happen frequently. If a public server provides dumplogs, other players that encounter bones may look up the dumplogs to see which one corresponds to the bones level and what items it contains were carried.

Some players consider this cheating and frown upon it, to the point of once being a subject of endless RGRN debates about the value of such wins. While using bones items in a normal game is perfectly fine, it can often make a difficult game much easier by providing items that the current player has not "earned" yet; speed runs typically do not load bones files at all unless actively performing bones-stuffed play.

With all this in mind, being able to "effortlessly" determine bones contents does not guarantee that a player will be able to use those items effectively, much less perform well in later stages of the game: Even with "perfect" outside knowledge of bones items, resources are still necessary to uncurse and properly utilize most of them, and this assumes that a character can reach the bones pile safely to begin with - every bones pile looks "free" until you are blindsided by Yeenoghu or a former character's pet arch-lich!

History

In NetHack 3.4.3 and some previous versions, including variants based on these versions, the statues and corpses of unique monsters will revive as those monsters - this is bug C342-54, and is fixed in NetHack 3.6.0 via commit fbfb8e92.

Variants

A user has suggested improving this page or section as follows:

"Add further information about changes introduced in variants (for example UnNetHack)."

SLASH'EM

In the Windows port of SLASH'EM, the portion of the filename containing the role name can be "Law", "Neu" and "Cha", which represents the alignment quests, and the letter representing the branch can be "N", which corresponds to the nymph level.

UnNetHack

In the Windows port of UnNetHack, the portion of the filename containing the letter representing the branch can be "N", which corresponds to the nymph level.

dNethack

In dNetHack, additional non-standard monsters can be left behind in place of a ghost if a bones file is created:

• Characters killed by dreadblossom swarms and shades that leave bones will become a monster of the same type behind instead of a ghost.
• Characters killed by dread seraphs leave behind skeletons.
• Characters killed by gnoll ghouls leave behind regular ghouls.
• Binders will always leave broken shadows instead of ghosts in a bones file.

Note that Mammon does not currently leave a golden statue in a bones file.

FIQHack

In FIQHack, bones are much more dangerous than in NetHack: any ghost or other monster will have the same intrinsics as the deceased character, and there is a ¹⁄₃ chance that the ghost will be replaced with a live player monster that has the same spells and intrinsics and access to their former inventory.

See also

• Hearse
• Ghost
• Options § bones