|Genre:||Adventure & Action||Status:|
|Category:||Adventure & Action ➤ Role-playing game ➤ RPG ➤ NetHack||Commercial:|
|Tags:||RPG; Exploration; Action; Adventure; Strategy; Hack and Slash; Class-Based; Procedural Generation; Perma Death; Persistent World; Fantasy; Difficult||Demo:|
|Released:||Latest : 3.6.6 / Dev : B87d224||Package Name:||nethack-common, nethack-x11|
|Quality (record):||Quality (game):|
|Contrib.:||Goupil & Louis||ID:||12055|
|[fr]:||Un roguelike libre et multi-plateforme très ancien et une référence (comme Rogue) pour les Hack and Slash. Son scénario est centré sur la quête de l'amulette de Yendor dans les souterrains de Gehennom. Contrairement à beaucoup d'autres Hack and Slash, l'accent est mis sur l'exploration de ses souterrains (générés de manière procédurale) et non pas simplement dans l'élimination de tout ce qui bouge. En fait, tuer tout ce qui bouge est la meilleur manière de mourir rapidement. Le joueur est accompagné d'un animal domestique qui l'aide dans sa progression.||[en]:||A very old libre and multi-platform roguelike and a reference (like Rogue) for Hack and Slash games. Its scenario is centered on the quest for Yendor's amulet in the dungeons of Gehennom. Unlike many other Hack and Slashes games, the emphasis is on exploring his dungeons (procedurally generated) and not simply eliminating anything that moves. In fact, killing anything that moves is the best way to die quickly. The player is accompanied by a pet that helps him in his progression.|
Présentation des utilisateurs / Users presents :
How To utilisateur / User How To :
Version courante / Current release (3.6.6) :
Gameplay [en] / [en] / [fr] : v.3.6.2, v.3.6.1, v.3.4.3
Quelques exemples / Some examples (Mods=GUI for Nethack) : Vulture, glhack,
Linux joue / Linux plays : Hex DSL,
Website & videos
[Homepage] [Dev site 1 2] [Features/About] [Screenshots 1 2] [Videos cv(3.6.6) cv(3.6.6) pv pv t ts gd gu id r lp ht ht sr sr mod(3.4.3) mod mod(3.4.3) mod g(3.6.2) g(3.6.1) g g g g g g g g g[fr](3.4.3) g[de] g[ru](3.6.6) g[ru] g[pl] g[cz] g[sp] g[pt] g[it] g[tr] g] [WIKI] [FAQ] [RSS] [Changelog 1 2 3]
Commercial : (empty)
• Graphical user interface for NetHack : [NetHackWiki (Graphical user interface)]
• NetzHack (German-localized version of NetHack) : [NetzHack [de]]
• Some resources for NetHack & others RPG : [Ali's NetHack Page]
[Open Hub] [PCGamingWiki] [MobyGames] [NetHackWiki]
Devs (The NetHack DevTeam 1 2 [fr] [en]) : [Site 1 2 3] [twitter] [YouTube] [Interview 1 2]
Game : [Blog] [Forums] [twitter] [YouTube]
On other sites
[Wikipedia (Nethack) [fr] [en] [de]]
[JeuxLinux [fr]] [Jeux libres [fr]] [The Linux Game Tome] [Wikia] [Debian] [Snap] [Linuxaria]
[Gamasutra (Game Design Essentials: 20 RPGs)] [h2g2]
News / Source of this Entry (SotE) / News (SotN)
[Changes with v. 3.6.6 (20200308)] [full circle magazine n°152 (201912) (SotN)] [HOLaRSE [de] (20200613)]
Un roguelike en ncurses dont l'histoire est centré sur la quête de l'amulette de Yendor, par The NetHack DevTeam.
C'est un jeu dérivé de Rogue.
NetHack est un roguelike libre et multi-plateforme très ancien et une référence (comme Rogue) pour les Hack and Slash. Son scénario est centré sur la quête de l'amulette de Yendor dans les souterrains de Gehennom. Contrairement à beaucoup d'autres Hack and Slash, l'accent est mis sur l'exploration de ses souterrains (générés de manière procédurale) et non pas simplement dans l'élimination de tout ce qui bouge. En fait, tuer tout ce qui bouge est la meilleur manière de mourir rapidement. Le joueur est accompagné d'un animal domestique qui l'aide dans sa progression.
Le graphisme de ce jeu peut-être amélioré par une interface graphique, néanmoins les déplacements restent en case par case (et tour par tour).
Le paquet netHack-x11 (en dépôts) par exemple, apporte une interface graphique et un contrôle à la souris.
D'autres interfaces graphiques sont disponibles (dans le Bottin) :
EbonHack, Falcon's Eye, glHack, Gtk2hack, Necklace of the Eye, Nethack 3D, Ne.W.T., noegnud, Vulture's Eye,
"En dépit de leurs apparences, de nombreux roguelikes sont très addictifs et amusants à jouer.
Leur graphisme simple peut masquer des mondes à la complexité rarement atteinte dans d'autres jeux".
L'équipe du projet MAngband.
Crédit image (lien ci-dessus) : Debian.
Jeu Dungeon Crawl – fichiers communs
Nethack est un jeu d’aventure de type Donjons & Dragons merveilleusement décalé, mais assez captivant. Le joueur choisit un type de personnage (comme magicien, garde ou touriste) et se met en quête de l’amulette de Yendor (essayez de le lire à l'envers) pour son dieu. En chemin il peut rencontrer un ou deux « mécaniciens quantiques » (monstres télé-porteurs) ou peut-être le roi Arthur, ou s'il a vraiment de la chance la « Bête vorace et microbienne de Traal ».
Un frontal pour NetHack doit être installé pour pouvoir jouer. Les paquets suivants comportent tous la version originale non graphique, et peuvent être installés simultanément :
— nethack-console : aucun graphisme, seulement le jeu NetHack pur ;
— nethack-x11 : la version originale X11 avec graphismes Athena ;
— nethack-lisp : version Lisp avec fenêtrage.
Les différents frontaux graphiques pour NetHack ont tous un grand nombre de fichiers en commun. Ce paquet fournit les graphismes, les niveaux de donjon et les utilitaires communs à tous les frontaux de NetHack.
Ce paquet fournit quelques utilitaires tels que recover pour récupérer des fichiers de sauvegarde automatique en cas de panne de courant, dgn_comp et lev_comp pour fabriquer ses propres niveaux et donjons de Nethack. L’utilitaire recover est exécuté à chaque démarrage du système s'il existe des fichiers de sauvegardes automatiques disponibles.
NetHack est un jeu vidéo sorti en 1987, dont le nom ne signifie pas qu'il se joue en réseau, mais qu'il a été conçu (hacked) en réseau (net) : c'est le résultat d'un travail collaboratif via Internet.
Il appartient à la famille des rogue-like et est un logiciel libre.
À l'origine, NetHack vient de Hack (sorti en 1984), lui-même suivant Rogue (1980). NetHack connaît de la même façon plusieurs descendances, dont Donjon Hack, une tentative commerciale, mais surtout Slash'EM (Super Lots of Added Stuff Hack - Extended Magic). Mais la branche principale de NetHack (dite version vanilla, c'est-à-dire au goût basique) est toujours activement maintenue en 2011 (la dernière version remonte à 2003 mais le site internet publie de temps à autre de nouveaux fichiers exécutables et des informations.
Le joueur est invité à choisir une classe, une race et un alignement, et se voit attribuer un animal domestique qui l'aide dans sa progression. Le dieu assigne au personnage de récupérer l'Amulette de Yendor dans Gehennom, le monde souterrain (appelé Enfers dans les versions précédentes). Il faut donc descendre, trouver le Magicien de Yendor, surnommé Rodney par les joueurs, lui prendre l'Amulette (dont le port complique sérieusement le jeu) et enfin remonter à la surface, avec 5 niveaux supplémentaires à la fin. On dit alors qu'on a réalisé une ascension, car les dieux élèveront au rang de demi-dieu le héros qui aura accompli cette tâche.
La difficulté principale, comme dans tous les roguelikes, vient du fait que le personnage ne peut être récupéré une fois que la mort survient. Et il y a de nombreuses manières de trépasser. Il faut également manger, pour ne pas mourir de faim (mais pas trop sous peine d'étouffer), mais en prenant soin d'éviter tous les pièges et poisons que l'on peut trouver. L'alignement permet de savoir quel dieu vous supporte, ce qui peut sauver le personnage plus d'une fois, et il détermine la conduite que vous devriez avoir. Quand un personnage meurt, il arrive que le niveau dans lequel il se trouve soit sauvegardé, pour être inséré plus tard dans une autre partie, avec la cause de sa perte ; ces niveaux sont appelés bones levels et on y retrouve le fantôme et ses possessions, généralement maudites.
Un joueur débutant dépasse rarement quelques niveaux (sur une cinquantaine, variant avec la partie). Il y a peu de cas de joueurs ayant fini le jeu en moins d'un an, même en consultant les aides de jeu.
NetHack est un jeu rendu particulièrement riche par l'imagination des développeurs, la DevTeam. Le proverbe coutumier est La DevTeam pense à tout ; en effet, de nombreux cas de figure sont mis en œuvre. Par exemple, tenter de verser une potion dans elle-même produirait
That is a potion bottle, not a Klein bottle!
"A very old libre and multi-platform roguelike and a reference (like Rogue) for Hack and Slash games" -- Le Bottin.
What is NetHack?
NetHack is a single player dungeon exploration game that runs on a wide variety of computer systems, with a variety of graphical and text interfaces all using the same game engine. Unlike many other Dungeons & Dragons-inspired games, the emphasis in NetHack is on discovering the detail of the dungeon and not simply killing everything in sight - in fact, killing everything in sight is a good way to die quickly. Each game presents a different landscape - the random number generator provides an essentially unlimited number of variations of the dungeon and its denizens to be discovered by the player in one of a number of characters: you can pick your race, your role, and your gender.
Recently, you have begun to find yourself unfulfilled and distant in your daily occupation. Strange dreams of prospecting, stealing, crusading, and combat have haunted you in your sleep for many months, but you aren't sure of the reason. You wonder whether you have in fact been having those dreams all your life, and somehow managed to forget about them until now. Some nights you awaken suddenly and cry out, terrified at the vivid recollection of the strange and powerful creatures that seem to be lurking behind every corner of the dungeon in your dream. Could these details haunting your dreams be real? As each night passes, you feel the desire to enter the mysterious caverns near the ruins grow stronger. Each morning, however, you quickly put the idea out of your head as you recall the tales of those who entered the caverns before you and did not return. Eventually you can resist the yearning to seek out the fantastic place in your dreams no longer. After all, when other adventurers came back this way after spending time in the caverns, they usually seemed better off than when they passed through the first time. And who was to say that all of those who did not return had not just kept going?
Asking around, you hear about a bauble, called the Amulet of Yendor by some, which, if you can find it, will bring you great wealth. One legend you were told even mentioned that the one who finds the amulet will be granted immortality by the gods. The amulet is rumored to be somewhere beyond the Valley of Gehennom, deep within the Mazes of Menace. Upon hearing the legends, you immediately realize that there is some profound and undiscovered reason that you are to descend into the caverns and seek out that amulet of which they spoke. Even if the rumors of the amulet's powers are untrue, you decide that you should at least be able to sell the tales of your adventures to the local minstrels for a tidy sum, especially if you encounter any of the terrifying and magical creatures of your dreams along the way. You spend one last night fortifying yourself at the local inn, becoming more and more depressed as you watch the odds of your success being posted on the inn's walls getting lower and lower.
In the morning you awake, collect your belongings, and set off for the dungeon. After several days of uneventful travel, you see the ancient ruins that mark the entrance to the Mazes of Menace. It is late at night, so you make camp at the entrance and spend the night sleeping under the open skies. In the morning, you gather your gear, eat what may be your last meal outside, and enter the dungeon...
2 What is going on here?
You have just begun a game of NetHack. Your goal is to grab as much treasure as you can, retrieve the Amulet of Yendor, and escape the Mazes of Menace alive.
Your abilities and strengths for dealing with the hazards of adventure will vary with your background and training:
• Archeologists understand dungeons pretty well; this enables them to move quickly and sneak up on the local nasties. They start equipped with the tools for a proper scientific expedition.
• Barbarians are warriors out of the hinterland, hardened to battle. They begin their quests with naught but uncommon strength, a trusty hauberk, and a great two-handed sword.
• Cavemen and Cavewomen start with exceptional strength but, unfortunately, with neolithic weapons.
• Healers are wise in medicine and apothecary. They know the herbs and simples that can restore vitality, ease pain, anesthetize, and neutralize poisons; and with their instruments, they can divine a being's state of health or sickness. Their medical practice earns them quite reasonable amounts of money, with which they enter the dungeon.
• Knights are distinguished from the common skirmisher by their devotion to the ideals of chivalry and by the surpassing excellence of their armor.
• Monks are ascetics, who by rigorous practice of physical and mental disciplines have become capable of fighting as effectively without weapons as with. They wear no armor but make up for it with increased mobility.
• Priests and Priestesses are clerics militant, crusaders advancing the cause of righteousness with arms, armor, and arts thaumaturgic. Their ability to commune with deities via prayer occasionally extricates them from peril, but can also put them in it.
• Rangers are most at home in the woods, and some say slightly out of place in a dungeon. They are, however, experts in archery as well as tracking and stealthy movement.
• Rogues are agile and stealthy thieves, with knowledge of locks, traps, and poisons. Their advantage lies in surprise, which they employ to great advantage.
• Samurai are the elite warriors of feudal Nippon. They are lightly armored and quick, and wear the dai-sho, two swords of the deadliest keenness.
• Tourists start out with lots of gold (suitable for shopping with), a credit card, lots of food, some maps, and an expensive camera. Most monsters don't like being photographed.
• Valkyries are hardy warrior women. Their upbringing in the harsh Northlands makes them strong, inures them to extremes of cold, and instills in them stealth and cunning.
• Wizards start out with a knowledge of magic, a selection of magical items, and a particular affinity for dweomercraft. Although seemingly weak and easy to overcome at first sight, an experienced Wizard is a deadly foe.
You may also choose the race of your character:
• Dwarves are smaller than humans or elves, but are stocky and solid individuals. Dwarves' most notable trait is their great expertise in mining and metalwork. Dwarvish armor is said to be second in quality not even to the mithril armor of the Elves.
• Elves are agile, quick, and perceptive; very little of what goes on will escape an Elf. The quality of Elven craftsmanship often gives them an advantage in arms and armor.
• Gnomes are smaller than but generally similar to dwarves. Gnomes are known to be expert miners, and it is known that a secret underground mine complex built by this race exists within the Mazes of Menace, filled with both riches and danger.
• Humans are by far the most common race of the surface world, and are thus the norm by which other races are often compared. Although they have no special abilities, they can succeed in any role.
• Orcs are a cruel and barbaric race that hate every living thing (including other orcs). Above all others, Orcs hate Elves with a passion unequalled, and will go out of their way to kill one at any opportunity. The armor and weapons fashioned by the Orcs are typically of inferior quality.
Dungeon crawl game - common files
NetHack is a wonderfully silly, yet quite addictive, Dungeons & Dragons-style adventure game. You play a character from one of many classes (such as wizard, ranger, or tourist), fighting your way down to retrieve the Amulet of Yendor (try saying THAT one backwards!) for your god. On the way, you might encounter a quantum mechanic or two, or perhaps King Arthur, or - if you're REALLY lucky - the Ravenous Bugblatter Beast of Traal.
You should install a front-end for NetHack if you wish to play the game. Each of them includes the original non-graphical version, and they can all be installed at the same time:
- nethack-console: no graphics, just plain NetHack;
- nethack-x11 : original X11/Athena-based graphical version;
- nethack-lisp : Lisp window version.
The various graphical front-ends for NetHack all share a large number of files in common. This package contains the graphics, dungeon levels, and utilities common to all NetHack front-ends.
It also provides a few utilities such as recover, for retrieving auto-save files in case of a power failure, and dgn_comp and lev_comp, two utilities for making your own NetHack levels and dungeons. The "recover" utility will be run every time the system boots, if there are any auto-save files available.
NetHack is a single-player roguelike video game originally released in 1987 with ASCII graphics. It is a descendant of an earlier game called Hack (1982), which is a clone of Rogue (1980). Comparing it with Rogue, Engadget's Justin Olivetti wrote that it took its exploration aspect and "made it far richer with an encyclopedia of objects, a larger vocabulary, a wealth of pop culture mentions, and a puzzler's attitude." In 2000, Salon described it as "one of the finest gaming experiences the computing world has to offer."
The player chooses a character race and class for the mission of retrieving the Amulet of Yendor in a randomly generated dungeon.
History and development
The first version of NetHack was released by Mike Stephenson on July 28, 1987.
A core development team emerged with the release of NetHack 3.0 in July 1989. Over the next 14 years of development they established a tight-lipped culture, revealing little, if anything, between releases. Owing to the ever-increasing depth and complexity found in each release, the development team enjoys a near-mythical status among some fans. This perceived omniscience is captured in the initialism TDTTOE, "The DevTeam Thinks of Everything".
Stephenson licensed the software under the NetHack General Public License, allowing other developers to release their own versions. The license is certified as open source by the Open Source Initiative.
For 12 years, the last version to include new gameplay features was NetHack 3.4.3, released in December 2003. Subsequent updates included new tilesets and compatibility with variants of Mac OS. In the absence of new releases from the developers, several variants developed by fans emerged.
On December 7, 2015, version 3.6.0 was released, the first major release in over a decade. While the patch did not add major new gameplay features, the update was designed to prepare the game for expansion in the future. NetHack remains "...one of the oldest games still being developed". A public read-only mirror of NetHack's git repository was made available on February 10, 2016. Version 3.6.1 was announced on April 28th, 2018, a return to a somewhat more frequent release schedule.
Before starting a game, players are asked to choose their character's race, role, gender, and alignment, or allow the game to assign the attributes randomly. There are traditional fantasy roles such as knight, wizard, rogue, and priest; but there are also unusual ones, including archaeologist, tourist, and caveman. The player character's role and alignment dictate which deity the character serves in the game and "how other monsters react toward you".
After the player character is created, the main objective is introduced. To win the game, the player must retrieve the Amulet of Yendor, found at the lowest level of the dungeon, and offer it to their deity. Successful completion of this task rewards the player with the gift of immortality, and the player is said to "ascend", attaining the status of demigod. In addition, a number of sub-quests must be completed, including one class-specific quest.
The player's character is, unless they opt not to be, accompanied by a pet animal, typically a kitten or little dog, although knights begin with a saddled pony. Pets grow from fighting, and they can be changed by various means. Most of the other monsters may also be tamed using magic or tempting food.
NetHack's dungeon spans about 50 primary levels, of which most are randomly generated when the player character first encounters them. A typical level contains a way "up" and "down" (these may be stairways, ladders, trapdoors etc.), along with several "rooms" joined by corridors. The "rooms" are randomly generated rectangles (as opposed to the linear corridors) and may contain features such as altars, shops, fountains, traps, thrones, pools of water, and sinks based upon the randomly generated features of the room. Some "special" levels are of fixed design in every game session.
Items and tools
A player's inventory, as displayed after application of the "menucolors" patch
NetHack features a variety of items: weapons (either ranged or melee), armor to protect the player; scrolls and spellbooks to read, potions to quaff, wands, rings, amulets, and an assortment of tools such as keys and lamps.
NetHack's identification of items is almost identical to Rogue's. For example, a newly discovered potion may be referred to as a 'pink potion' with no other clues as to its identity. Players can perform a variety of actions and tricks to deduce, or at least narrow down, the identity of the potion. The most obvious is the somewhat risky tactic of simply drinking it. All items of a certain type will have the same description; for instance, all scrolls of enchant weapon may be labeled 'TEMOV', and once one has been identified, all scrolls of enchant weapon found will be labeled unambiguously as such. Starting a new game will scramble the items' descriptions again, so the 'silver ring' that is a ring of levitation in one game might be a ring of hunger in another.
Blessings and curses
As in many other roguelike games, all items in NetHack are either "blessed", "uncursed", or "cursed". The majority of items are found uncursed, but the blessed or cursed status of an item is unknown until it is identified or detected through other means.
Generally, a blessed item will be more powerful than an uncursed item, and a cursed item will be less powerful, with the added disadvantage that once it has been equipped by the player, it cannot be easily unequipped. Where an object would bestow an effect upon the character, a curse will generally make the effect harmful, or increase the amount of harm done. There are exceptions, however, which are usually very specific – for example, drinking a cursed potion of gain level will make the character literally rise through the ceiling to the level above, instead of gaining an experience level.
As in other rogue-like games, NetHack features permadeath: expired characters cannot be revived without having made backup copies of the actual save files.
Although NetHack can be completed by new or intermediate players without any artificial limitations, experienced players can attempt "conducts" for an additional challenge. These are voluntary restrictions on actions taken, such as using no wishes, following a vegetarian or even vegan diet, or even killing no monsters. While conducts are generally tracked by the game and are displayed at death or ascension, unofficial conducts are practiced within the community.
When a player dies, the cause of death and score is created and added to the list where the player's character is ranked against other previous characters. The prompt "Do you want your possessions identified?" is given by default at the end of any game, allowing the player to learn any unknown properties of the items in the inventory at death. Player's attributes (such as resistances, luck, and others), conduct (usually self-imposed challenges, such as playing as an atheist or a vegetarian), and a tally of creatures killed, may also be displayed.
The game sporadically saves a level on which a character has died and then integrates that level into a later game. This is done via "bones files", which are saved on the computer hosting the game. A player using a publicly hosted copy of the game can thus encounter the remains and possessions of many other players, although many of these possessions may have become cursed.
Culture around spoilers
NetHack is largely based on discovering secrets and tricks during gameplay. It can take years for one to become well-versed in them, and even experienced players routinely discover new ones. A number of NetHack fan sites and discussion forums offer lists of game secrets known as "spoilers". Fans of NetHack consider an ascension without having read spoilers very prestigious; the achievement is so difficult that some question whether it has been or can be accomplished.
NetHack was originally created with only a simple ASCII graphical user interface, although the option to use something more elaborate was added later in its development. Interface elements – environment, entities, and objects – are represented by arrangements of ASCII or Extended ASCII glyphs used in plain text, "DEC graphics" or "IBM graphics" mode. In addition to the environment, the interface also displays character and situational information.
A detailed example:
You see here a silver ring.
--------------- ###------------ |...(|
|...%...........### # ## |....|
+.......<......| ### ### |..!.|
--------------- # # ------
Hacker the Conjurer St:11 Dx:13 Co:12 In:11 Wi:18 Ch:11 Neutral
Dlvl:3 $:120 HP:39(41) Pw:36(36) AC:6 Exp:5 T:1073
The player (the '@' sign, a wizard in this case) has entered the level via the stairs (the '<' sign) and killed a few monsters, leaving their corpses (the '%' signs) behind. Exploring, the wizard has uncovered three rooms joined by corridors (the '#' signs): one with an altar (the '_' sign), another empty, and the final one (that the wizard is currently in) containing a potion (the '!' sign), chest (the '(' sign), and has just moved onto a square containing a silver ring. Parts of the level are still unexplored (probably accessible through the door to the west (the '+' sign)) and the player has yet to find the downstairs (a '>' sign) to the next level.
Apart from the original termcap interface shown above, there are interfaces that replace standard screen representations with two-dimensional images, or tiles, collectively known as "tiles mode". Graphic interfaces of this kind have been successfully implemented on the Amiga, the X Window System, the similar Microsoft Windows GUI, the Qt toolkit, or the GNOME libraries.
Enhanced graphical options also exist, such as the isometric perspective of Falcon's Eye and Vulture's Eye, or the three-dimensional rendering that noegnud offers. Vulture's Eye is a fork of the now defunct Falcon's Eye project. Vulture's Eye adds additional graphics, sounds, bug fixes and performance enhancements and is under active development in an open collaborative environment.
Bugs, humorous messages, stories, experiences, and ideas for the next version are discussed on the Usenet newsgroup rec.games.roguelike.nethack.
A public server at nethack.alt.org, commonly known as NAO, gives access to NetHack through a Telnet or SSH interface. A Java Telnet emulator is also available on the same site. Ebonhack connects to NAO with a graphical tiles-based interface.
During the whole month of November, the annual /dev/null NetHack Tournament takes place. It has been held every year since 1999. The Junethack Cross-Variant Summer Tournament has taken place annually since 2011.
Ports and forks
The NetHack General Public License allows anyone to create a fork or port it to a platform not supported by the official DevTeam, provided that they use the same license. Over the years this licensing has led to a large number of ports and forks (e.g. Slash'EM and UnNetHack) as well as versions in German, Japanese and Spanish.
NetHack General Public License
The NetHack General Public License is a copyleft software license certified as an open source license by the Open Source Initiative.
The license was written in 1989 by Mike Stephenson, who patterned it after the GNU bison license (which was written by Richard Stallman in 1988). Like the Bison license, and Stallman's later GNU General Public License, the NetHack license was written to allow the free sharing and modification of the source code under its protection. At the same time, the license explicitly states that the source code is not covered by any warranty, thus protecting the original authors from litigation.
The NetHack GPL requires all derivative works to be distributed under the same license, except that the creator of a derivative work is allowed to offer warranty protection on the new work. The derivative work is required to indicate the modifications made and the dates of changes. In addition, the source code of the derivative work must be made available, free of charge except for nominal distribution fees.