bone-340.txt Last edited 2002-11-27 for NetHack 3.4.0
Leaving and loading bones files in NetHack 3.4
Compiled by Dylan O'Donnell <psmith@spod-central.org>
HTML Conversion by Kate
Nepveu.
While NetHack is a single-player game, a certain amount of interaction between games (and, on a multi-user system, between players) is provided by bones files; levels on which a previous character has died being loaded into a new game for a new character to encounter, complete with the ghost of the former adventurer and their belongings (or indeed ghosts, since bones levels can be themselves left as bones should you die there).
On any given system, only one bones file can be waiting at any time for each distinct level. For this purpose, special levels are considered distinct from normal ones; for example, an Oracle level at DL 6 can leave bones despite the prior presence of a stored bones file for a regular Dungeons level at that depth, and can be loaded in at a different depth if that's where the Oracle happens to be located in the new game.
Some levels are ineligible to be saved as bones under any circumstances, and should you die on these levels you will never leave a bones file:
* This is a consequence of the formula given below
** If at DL3, as a consequence of the formula given below
This means that the following levels are eligible to leave bones and have bones files loaded for them (provided they don't contain the entrance to another dungeon branch):
* Stored bones for Mines level 1 may be loaded at DL3, but not left at that depth.
If you die on a level that is eligible to leave bones, the chance of your doing so is dependent on the depth of that level: 1-(1/(1+(DL/4))) (note that this, combined with NetHack's use of integer arithmetic, means that no level above DL 4 will ever leave bones). No other factors are considered: "Nothing else. Not how you died, not what level you were, not what's in your inventory, not whether it was loaded as bones, not any intrinsics or god status or nearby monster." (from a Usenet article).
When bones are saved, you and your possessions are saved along with them, along with the level layout, objects, and monsters. There are, however, certain modifications made:
You leave a corpse, under most circumstances. If you were polymorphed and unchanging, it will be that of your monster form (if that can leave corpses); otherwise, it will be that of a human representative of your role, regardless of your race. No corpse will be left if you are disintegrated, burned to death, die while unchanging and polymorphed into a monster that does not leave corpses, or arise from the dead as a different monster as detailed below. If you are stoned, you will instead leave a statue containing your possessions.
If you leave a corpse, a grave is created (with the tombstone bearing your character's name and manner of death) if the location is one where a grave can occur (a non-trapped "floor of a room" square of open space).
You become a ghost, under most circumstances. If you died by sliming, you instead arise from the dead as a green slime. If you were killed by any W, you arise from the dead as a wraith; by any M, as a mummy of your race; by any V and you are human, as a vampire; by a ghoul, as a ghoul. In each case, the monster you arise as will be carrying your possessions. If you are stoned, no ghost is created.
Items that were in your character's main inventory each have an 80% chance of becoming cursed, if they weren't already. Items that were inside containers are unaffected, whether the container is cursed or not.
Some monsters will never be saved in bones: the Wizard of Yendor, your Quest Nemesis and Leader, Vlad the Impaler, and Medusa.
When you first arrive at a level for which bones are eligible to be loaded and for which a stored bones file exists on the system, there is a flat 1/3 chance that that file will be loaded.
The monsters on the level will have their peaceful status adjusted to suit the character arriving there (for example, just because the dwarfs and gnomes on a Mines level were peaceful towards the dwarvish character that died there, doesn't mean they'll be peaceful towards your orc who's found those bones). In particular, this means that the previous character's pets will often be found hostile.
Artifacts in the bones file that exist or have existed in the new game will be converted to an ordinary non-artifact object of their type, as will the Quest Artifact for the new character's role. The four Unique Items will become normal items: the Amulet of Yendor a cursed cheap plastic imitation, the Bell of Opening a cursed bell, the Book of the Dead a cursed blank spellbook, and the Candelabrum of Invocation a number of partly-used wax candles corresponding to the number of candles (of any type) as had been in the Candelabrum (at least one). Tins of unique monsters will become empty.
Generally, bones files created by different versions of NetHack, or builds on different platforms or with different compile options, will not be compatible with each other. Bones created by a sufficiently similar build of the same version on a sufficiently similar platform may be compatible enough to be loaded; you can move them into place manually, or use a bones exchange service such as Hearse (http://www.krollmark.com/hearse/).
Corrections and clarifications provided by John Cater, Dayv, Jukka Lahtinen, and Spike.