View source for NetHack

{{short description|1987 text-based roguelike video game}}
{{Use dmy dates|date=February 2020}}
{{Infobox software
| title = ''NetHack''
| name = 
| screenshot = Nethack releasing a djinni.png
| caption = A released [[genie|djinni]] grants the player a wish.
| developer = [https://www.nethack.org/v360/Guidebook.html#_TOCentry_60 The NetHack DevTeam]
| license = NetHack General Public License (derivative of BISON general public license, a precursor to the [[GNU General Public Licence|GPL]])
| released = 1.3d / {{Start date and age|df=yes|1987|7|28}}<ref>{{Cite web|url=http://ftp.acc.umu.se/mirror/archive/ftp.sunet.se/pub/usenet/ftp.uu.net/comp.sources.games/volume2/nethack/part01.gz |access-date=2016-04-23|title=part01.gz}}</ref>
| latest release version = {{wikidata|property|preferred|references|edit|P348|P548=Q2804309}}                                             | latest release date    = {{Start date and age|{{wikidata|qualifier|preferred|single|P348|P548=Q2804309|P577}}|df=yes}}
| operating system = [[Windows]], [[Linux]], [[Mac OS X]], [[Windows CE]], [[OS/2]], [[BSD|*BSD]], [[System V]], [[Solaris (operating system)|Solaris]], [[HP-UX]], [[BeOS]], [[OpenVMS|VMS]], [[Haiku (operating system)|Haiku]]<ref>{{cite web | url = https://www.nethack.org/v367/downloads.html | title = Nethack 3.6.7 Downloads}}</ref><ref>[https://depot.haiku-os.org/#!/pkg/nethack/haikuports/3/6/2/-/1/x86_64?bcguid=bc199-JRVA NetHack] – HaikuDepot</ref>
| genre = [[Roguelike]]
}}

'''''NetHack''''' is an [[open source]] single-player [[roguelike]] [[video game]], first released in 1987 and maintained by the NetHack DevTeam. The game is a [[Fork (software development)|fork]] of the 1984 game ''[[Hack (video game)|Hack]]'', itself inspired by the 1980 game ''[[Rogue (video game)|Rogue]]''. The player takes the role of one of several pre-defined [[character class]]es to descend through multiple dungeon floors, fighting monsters and collecting treasure, to recover the "Amulet of Yendor" at the lowest floor and then escape.<ref>{{Cite web|title = The Best Games You've Never Played|url = http://www.bit-tech.net/gaming/pc/2007/12/28/the_best_games_you_ve_never_played/1|website = bit-tech|access-date = 2015-11-08}}</ref><ref>{{Cite news |last=Au |first=Wagner James|title=Back to the Dungeon |newspaper=[[Wired (magazine)|Wired]] |date=August 1997|url=https://www.wired.com/wired/archive/5.08/streetcred.html?pg=3}}</ref>

As an exemplar of the traditional "roguelike" game, ''NetHack'' features [[Turns, rounds and time-keeping systems in games|turn-based]], grid-based [[hack and slash]] and [[dungeon crawl]]ing gameplay, [[Procedural generation|procedurally generated]] dungeons and treasure, and [[permadeath]], requiring the player to restart the game anew should the [[player character]] die. The game uses simple [[ASCII]] graphics by default so as to display readily on a wide variety of [[Computer terminal|computer displays]], but can use [[Curses (programming library)|curses]] with [[box-drawing character]]s, as well as substitute graphical tilesets on machines with graphics. While ''Rogue'', ''Hack'' and other earlier roguelikes stayed true to a [[high fantasy]] setting, ''NetHack'' introduced humorous and [[Anachronism|anachronistic]] elements over time, including [[Popular culture|popular cultural]] reference to works such as ''[[Discworld]]'' and ''[[Raiders of the Lost Ark]]''.

It is identified as one of the "major roguelikes" by John Harris.<ref>{{Cite web |last=Harris |first=John |title=Analysis: The Eight Rules Of Roguelike Design |url=https://www.gamedeveloper.com/pc/analysis-the-eight-rules-of-roguelike-design |access-date=2020-09-27 |website=[[Game Developer (website)|Game Developer]] |date=2 February 2011 |language=en}}</ref> 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."<ref>{{Cite web|title = The Game Archaeologist: A brief history of roguelikes|url = https://www.engadget.com/2014/01/18/the-game-archaeologist-a-brief-history-of-roguelikes/ |website = [[Engadget]] |access-date = 2015-11-09 |first = Justin |date=2014-01-18 |last = Olivetti}}</ref> In 2000, ''[[Salon (website)|Salon]]'' described it as "one of the finest gaming experiences the computing world has to offer".<ref name='Salon 2000-01-26'>{{Cite web|url=https://www.salon.com/2000/01/27/nethack/ |title=The best game ever |access-date=2015-04-03 |last=Au |first=Wagner James |date=2000-01-26 |work=[[Salon (website)|Salon]] |archive-url=https://web.archive.org/web/20080113042211/http://archive.salon.com/tech/feature/2000/01/27/nethack/ |archive-date=2008-01-13}}</ref>

==Gameplay==
Before starting a game, players choose their character's [[Character race|race]], [[character class|role]], [[sex]], and [[alignment (role-playing games)|alignment]], or allow the game to assign the attributes randomly. There are traditional fantasy roles such as [[knight]], [[wizard (character class)|wizard]], [[rogue (character class)|rogue]], and [[Cleric (character class)|priest]]; but there are also unusual roles, including [[archaeologist]], [[tourist]], and [[caveman]].<ref>{{Cite web|url=http://www.nethack.org/v360/Guidebook.html#_TOCentry_3 |title=NetHack 3.6.0: Guidebook for NetHack 3.6 |publisher=nethack.org |access-date=2016-04-23}}</ref> The [[player character]]'s role and alignment dictate which [[deity]] the character serves and is supported by in the game, "how other monsters react toward you", as well as character skills and attributes.<ref>{{Cite web|url=http://www.nethack.org/v360/Guidebook.html#_TOCentry_5 |title=NetHack 3.6.0: Guidebook for NetHack 3.6 |publisher=nethack.org |access-date=2016-04-23}}</ref>

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]]. Along the path to the amulet, a number of sub-quests must be completed, including one class-specific quest.

There are three major antagonists in NetHack: the [[Lucifer]]esque god [[Moloch]], who stole the Amulet of Yendor from the [[creator god]] [[Marduk]]; the high priest (or priestess) of Moloch, who holds the Amulet of Yendor; and the most prominent antagonist, the Wizard of Yendor, who will stalk the player throughout the rest of the game after the first encounter by resurrecting and attacking them periodically. The game's [[Final boss (video games)|final bosses]] in the [[astral plane|Astral Plane]] are the Riders: three of the [[Four Horsemen of the Apocalypse]], Death, Famine and Pestilence. It is often proposed that the player character represents the fourth horseman, War.{{citation needed|date=August 2024}}

The player's character is, unless they opt not to be, accompanied by a pet animal, typically a [[kitten]] or [[dog|little dog]], although knights begin with a [[saddle]]d [[pony]].<ref>{{Cite web|url=http://www.nethack.org/v343/Guidebook.html#_TOCentry_17 |title=NetHack 3.4.3: Guidebook for NetHack 3.4 |publisher=Nethack.org |access-date=2010-09-08}}</ref> Pets grow from fighting, and they can be changed by various means. Most of the other monsters may also be tamed using magic or food.

===Dungeon levels===
''NetHack'''s dungeon spans about fifty primary levels, most of which are [[procedural generation|procedurally generated]] when the player character enters them for the first time. A typical level contains a way "up" and "down" to other levels. These may be stairways, ladders, trapdoors, etc. Levels also contain several "rooms" joined by corridors. These 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 on the randomly generated features of the room. Some specific levels follow one of many fixed designs or contain fixed elements. Later versions of the game added special branches of dungeon levels. These are optional routes that may feature more challenging monsters but can reward more desirable treasure to complete the main dungeon. Levels, once generated, persist throughout a single game, in contrast to the non-persistent levels in ''[[Moria (1983 video game)|Moria]]''-style games.<ref name="arstech roguelikes">{{cite web | url = https://arstechnica.com/gaming/2020/03/ascii-art-permadeath-the-history-of-roguelike-games/ | title= ASCII art + permadeath: The history of roguelike games | first= Richard C. | last = Moss |date = March 19, 2020 | access-date = June 26, 2020 | work = [[Ars Technica]]}}</ref>

===Items and tools===
[[File:Nethack-inventory.png|250px|thumb|A player's inventory]]
''NetHack'' features a variety of items: [[weapon]]s (melee or ranged), [[armor]] to protect the player, [[scroll]]s and spellbooks to read, [[potion]]s to [[wiktionary:quaff|quaff]], wands, rings, amulets, and an assortment of [[tool]]s, such as keys and lamps.<ref>{{Cite web|url=http://www.nethack.org/v343/Guidebook.html#_TOCentry_20 |title=NetHack 3.4.3: Guidebook for NetHack 3.4 |publisher=Nethack.org |access-date=2010-09-08}}</ref>

''NetHack''<nowiki>'</nowiki>s identification of items is almost identical to ''[[Rogue (computer game)|Rogue]]''<nowiki>'</nowiki>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.<ref>{{Cite web|url=http://www.nethack.org/v343/Guidebook.html#_TOCentry_51 |title=NetHack 3.4.3: Guidebook for NetHack 3.4 |publisher=Nethack.org |access-date=2010-09-08}}</ref> 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 later 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 "[[blessing|blessed]]", "uncursed", or "[[curse]]d".<ref>{{Cite web |url=http://www.nethack.org/v343/Guidebook.html#_TOCentry_21 |title=NetHack 3.4.3: Guidebook for NetHack 3.4 |publisher=Nethack.org |access-date=2010-09-08}}</ref> 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. Such statuses can be changed (blessed to uncursed, uncursed to cursed, and vice versa) depending on player interaction.

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. However, there are very specific exceptions. 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]].

===Character death===
As in other roguelike games, ''NetHack'' features [[permadeath]]: expired characters cannot be revived.

Although ''NetHack'' can be completed without any artificial limitations, experienced players can attempt "conducts" for an additional challenge.<ref>{{Cite web|url=http://www.nethack.org/v343/Guidebook.html#_TOCentry_38 |title=NetHack 3.4.3: Guidebook for NetHack 3.4 |publisher=Nethack.org |access-date=2010-09-08}}</ref> These are voluntary restrictions on actions taken, such as using no wishes, following a [[vegetarian]] or [[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.<ref>{{Cite web|title = GameSetWatch @ Play: Thou Art Early, But We'll Admit Thee|url = http://www.gamesetwatch.com/2006/10/_play_thou_art_early_but_well_1.php|website = www.gamesetwatch.com|access-date = 2015-11-09|archive-date = 6 March 2016|archive-url = https://web.archive.org/web/20160306032222/http://www.gamesetwatch.com/2006/10/_play_thou_art_early_but_well_1.php|url-status = dead}}</ref> 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 their inventory at death. The 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.<ref>{{Cite web|url=http://hearse.krollmark.com/ |title=Hearse |access-date=2008-12-15}}</ref>

Because of the numerous ways that a player-character could die between a combination of their own actions as well as from reactions from the game's interacting systems, players frequently refer to untimely deaths as "Yet Another Stupid Death" (YASD). Such deaths are considered part of learning to play ''NetHack'' as to avoid conditions where the same death may happen again.<ref name="arstech roguelikes"/>

''NetHack'' does allow players to save the game so that one does not have to complete the game in one session, but on opening a new game, the previous save file is subsequently wiped as to enforce the permadeath option. One option some players use is to make a backup copy of the save game file before playing a game, and, should their character die, restoring from the copied version, a practice known as "save scumming". Additionally, players can also manipulate the "bones files" in a manner not intended by the developers. While these help the player to learn the game and get around limits of permadeath, both are considered forms of cheating the game.<ref>{{cite book | title = Role-Playing Game Studies | chapter = Single-Player Computer Role-Playing Games | first1 = Douglas | last1 =  Douglas | first2= Jon | last2= Peterson | first3 = Martin | last3= Picard | pages = 107–129 | publisher = Taylor & Francis | date = 2018 | editor-first1 = Sebastian | editor-last1 = Deterding | editor-first2 =  José | editor-last2= Zagal | isbn = 978-1317268314}}</ref>

===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.<ref>{{Cite web|url=http://sequoia.ict.pwr.wroc.pl/~witold/aiarr/2009_projekty/elitmod/|title=Reinforcement Learning for roguelike type games (eliteMod v0.9)}}</ref> A number of ''NetHack'' fan sites and discussion forums offer lists of game secrets known as "spoilers".<ref>{{Cite web |url=http://www.statslab.cam.ac.uk/~eva/nethack/spoilerlist.html |title=List of Nethack Spoilers |publisher=Statslab.cam.ac.uk |access-date=2010-09-08 |archive-url=https://web.archive.org/web/20091010042024/http://www.statslab.cam.ac.uk/~eva/nethack/spoilerlist.html |archive-date=10 October 2009 |url-status=dead}}</ref>

===Interface===
{{More citations needed section|date=May 2025}} 
''NetHack'' was originally created with only a simple ASCII [[text-based user interface]], although the option to use something more elaborate was added later in its development. Interface elements such as the environment, entities, and objects are represented by arrangements of [[ASCII]] or [[Extended ASCII]] glyphs, "[[DEC Special Graphics|DECgraphics]]", or "[[Code page 437|IBMgraphics]]" mode. In addition to the environment, the interface also displays character and situational information.

A detailed example:
<pre>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</pre>

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 player has uncovered three rooms joined by corridors (the '#' signs): one with an altar (the '_' sign), another empty, and the final one (that the player is currently in) containing a potion (the '!' sign) and chest (the '(' sign). The player 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 other interfaces that replace standard screen representations with [[2D computer graphics|two-dimensional]] images, or [[Tile-based video game|tiles]], collectively known as "tiles mode". [[Graphical user interface|Graphic interfaces]] of this kind have been successfully implemented on the [[Amiga]], the [[X Window System]], the [[Microsoft Windows]] GUI, the [[Qt (toolkit)|Qt toolkit]], and the [[GNOME]] libraries.

Enhanced graphical options also exist, such as the [[Isometric video game graphics|isometric perspective]] of ''[[Falcon's Eye]]'' and ''Vulture's Eye'', or the [[3D computer graphics|three-dimensional]] rendering that noegnud offers. ''Vulture's Eye'' is a [[Fork (software development)|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.

<gallery mode="packed" heights="150px" style="text-align:left">
File:NetHack for Windows Screenshot.png|''NetHack'' for Microsoft Windows in "tiles mode"
File:Vultures-2.1.0 screenshot.jpg|''Vulture's Eye'' offers an isometric perspective.
File:NeXTSTEP Nethack.png|''NetHack'' on [[OPENSTEP]]/[[NeXTSTEP]]
</gallery>

==History and development==
<small>{{Video game timeline | float="left"
| title = Major ''NetHack'' releases
| 1987a = v1.3d (First public release)
| 1987b = v2.2a
| 1989  = v3.0.0
| 1993  = v3.1.0
| 1996  = v3.2.0
| 1999  = v3.3.0
| 2002  = v3.4.0
| 2015  = v3.6.0
| last = 2025
}}</small>
''NetHack'' is a software derivative of ''Hack'', which itself was inspired by ''Rogue''. ''Hack'' was created by students Jay Fenlason, Kenny Woodland, Mike Thome, and [[JOVE|Jonathan Payne]] at [[Lincoln-Sudbury Regional High School]] as part of a computer class, after seeing and playing ''Rogue'' at the [[University of California, Berkeley]] computer labs.<ref name="craddock chapter 5">Craddock 2015, Chapter 5: "When the Inmates Run the Asylum - Hack-ing at Lincoln-Sudbury High School"</ref> The group had tried to get the source code of ''Rogue'' from [[Glenn Wichman]] and Michael Toy to build upon, but Wichman and Toy had refused, forcing the students to build the dungeon-creation routines on their own. As such, the game was named ''Hack'' in part for the hack-and-slash gameplay and that the code to generate the dungeons was considered a [[Kludge|programming hack]].<ref name="craddock chapter 5"/> After their classes ended, the students' work on the program also ended, though they had a working game. Fenlason provided the [[source code]] to a local [[USENIX]] conference, and eventually it was uploaded to [[USENET]] newsgroups. The code drew the attention of many players who started working to modify and improve the game as well as port it to other computer systems.<ref name="craddock chapter 5"/> ''Hack'' did not have any formal maintainer and while one person was generally recognized to hold the main code to the current version of ''Hack'', many software forks emerged from the unorganized development of the game.<ref name="craddock chapter 5"/>

Eventually, Mike Stephenson took on the role as maintainer of the ''Hack'' source code. At this point, he decided to create a new fork of the game, bringing in novel ideas from [[Izchak Miller]], a philosophy professor at [[University of Pennsylvania]], and Janet Walz, another computer hacker. They called themselves the DevTeam and renamed their branch ''NetHack'' since their collaboration work was done over the Internet.<ref name="craddock chp6">Craddock 2015, Chapter 6: "It Takes a Village: Raising NetHack"</ref> They expanded the bestiary and other objects in the game, and drew from other sources outside of the high fantasy setting, such as from ''[[Discworld]]'' with the introduction of the tourist character class.<ref>{{cite web | url = http://www.rockpapershotgun.com/2015/12/08/nethack-roguelike-update/ | title = The Twelve Years Of Nethack: Version 3.6.0 Out Now | first = Adam | last = Smith | date = December 8, 2015 | access-date = December 8, 2015 | work = [[Rock Paper Shotgun]]}}</ref> Knowing of the multiple forks of ''Hack'' that existed, the DevTeam established a principle that while the game was open source and anyone could create a fork as a new project, only a few select members in the DevTeam could make modifications to the main source repository of the game, so that players could be assured that the DevTeam's release was the legitimate version of ''NetHack''.<ref name="craddock chp6"/>

===Release history===
The DevTeam's first release of ''NetHack'' was on 28 July 1987.<ref name=":0">{{Cite web|title = Happy 20th birthday, 'NetHack'! – CNET |url = http://www.cnet.com/news/happy-20th-birthday-nethack/|website = CNET |access-date = 2015-11-09}}</ref>

The core DevTeam had expanded with the release of ''NetHack'' 3.0 in July 1989. By that point, they had 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 fans. This perceived omniscience is captured in the initialism TDTTOE, "The DevTeam Thinks of Everything", in that many of the possible [[emergent gameplay]] elements that could occur due to the behavior of the complex game systems had already been programmed in by the DevTeam.<ref name="craddock chp6"/> Since version 3.0, the DevTeam has typically kept to minor bug fix updates, represented by a change in the third version number (e.g. v3.0.1 over v3.0.0), and only releases major updates (v3.1.0 over v3.0.0) when significant new features are added to the game, including support for new platforms. Many of those from the community that helped with the ports to other systems were subsequently invited to be part of the DevTeam as the team's needs grew, with Stephenson remaining the key member currently.<ref name="gd 2016"/>

Updates to the game were generally regular from around 1987 through 2003, with the DevTeam releasing v3.4.3 in December 2003.<ref name=":0" /> Subsequent updates from the DevTeam included new tilesets and compatibility with variants of Mac OS, but no major updates to the game had been made.<ref>{{Cite web|author=Kenneth Lorber |url=http://www.nethack.org/ |title=NetHack |year=2009 |access-date=2011-04-08}}</ref> In the absence of new releases from the developers, several community-made updates to the code and variants developed by fans emerged.<ref name="gd 2016">{{cite web | url = https://www.gamedeveloper.com/design/the-story-behind-i-nethack-i-s-long-awaited-update--the-first-since-2003 | title = The story behind NetHack's long-awaited update--the first since 2003 | first = John | last = Bridgman | date = April 15, 2016 | access-date = June 26, 2020 | work=[[Game Developer (website)|Game Developer]] }}</ref>

On 7 December 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, with the DevTeam's patch notes stating: "This release consists of a series of foundational changes in the team, underlying infrastructure and changes to the approach to game development".<ref>{{Cite web|author=Kenneth Lorber |url=http://nethack.org/|title=NetHack |year=2015 |access-date=2015-12-07}}</ref><ref name="gd 3.6.0">{{cite web | url = https://www.gamedeveloper.com/design/-i-nethack-i-gets-first-major-update-in-over-a-decade | title = NetHack gets first major update in over a decade | first = Chris | last = Kerr | date = 8 December 2015 | access-date = 8 December 2015 | work=[[Game Developer (website)|Game Developer]]}}</ref> Stephenson said that despite the number of roguelike titles that had emerged since the v3.4.3 release, they saw that ''NetHack'' was still being talked about online in part due to its high degree of portability, and decided to continue its development.<ref name="gd 2016"/> According to DevTeam member Paul Winner, they looked to evaluate what community features had been introduced in the prior decade to improve the game while maintaining the necessary balance.<ref name="gd 2016"/> The update came shortly after the death of [[Terry Pratchett]], whose ''Discworld'' had been influential on the game, and the new update included a tribute to him.<ref name="gd 3.6.0"/> With the v3.6.0 release, ''NetHack'' remains "one of the oldest games still being developed".<ref>{{Cite web|author=Eli |url=http://jayisgames.com/archives/2006/07/nethack.php|title=NetHack |work=[[Jay Is Games]] |date=2006-07-16 |access-date=2008-12-15}}</ref>

A public read-only mirror of ''NetHack''{{'s}} [[git]] repository was made available on 10 February 2016.<ref>{{cite web | url = http://nethack.org/common/git.html | title=Information for NetHack Developers | work=NetHack | access-date=2016-02-11}}</ref> Since v3.6.0, the DevTeam has continued to push updates to the title, with the latest being v3.6.7 on 16 February 2023.<ref>{{cite web | url = https://www.nethack.org/v367/release.html | title = NetHack 3.6.7 Release Notes | access-date = 20 March 2023 | publisher = NetHack DevTeam}}</ref> Version 3.7.0 is currently in development.<ref>{{cite web|title=Official NetHack Git Repository|url=https://github.com/nethack/nethack|website=GitHub|access-date=28 December 2019}}</ref>

{{As of|2020}}, the official source release supports the following systems: [[Microsoft Windows|Windows]], [[Linux]], [[macOS]], [[Windows Embedded Compact|Windows CE]], [[OS/2]], [[Unix]] ([[Berkeley Software Distribution|BSD]], [[UNIX System V|System V]], [[Solaris (operating system)|Solaris]], [[HP-UX]]), [[BeOS]], and [[OpenVMS|VMS]].<ref name="nh366-dl">{{cite web |title=NetHack 3.6.6: Downloads |url=https://www.nethack.org/v366/downloads.html |website=NetHack |access-date=March 25, 2020}}</ref>

===Licensing, ports, and derivative ports===
{{Infobox software license
| name = NetHack General Public License (NGPL)
| image = 
| caption = 
| author = Mike Stephenson et al.
| version = 
| date = 1989
| OSI approved = Yes
| Debian approved = 
| FSF approved = 
| GPL compatible = 
| copyleft = Yes
| linking = 
| website = https://www.nethack.org/common/license.html
}}
''NetHack'' is released under the NetHack General Public License, which was written in 1989 by Mike Stephenson, patterned after the [[GNU bison]] license (which was written by [[Richard Stallman]] in 1988).<ref>GNU Bison is no longer distributed under the original Bison license; it has been distributed under an extension of the [[GNU General Public License]] since at least 1991.[http://dinosaur.compilertools.net/bison/bison_3.html]</ref> 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 General Public License is a [[copyleft]] [[software license]] certified as an [[open source license]] by the [[Open Source Initiative]].<ref>{{cite web|url=https://opensource.org/licenses/alphabetical|title=Licenses by Name|website=Open Source Initiative|access-date=16 December 2015}}</ref><ref>{{Cite web |url=https://opensource.org/licenses/NGPL |access-date=2016-04-23 |title=The Nethack General Public License (NGPL) |publisher=opensource.org |archive-date=29 April 2016 |archive-url=https://web.archive.org/web/20160429115623/https://opensource.org/licenses/NGPL |url-status=dead }}</ref>

The NetHack General Public License allows anyone to [[Porting|port]] the game 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 internationalized versions<ref>{{Cite web|url=https://nethackwiki.com/wiki/NetHack_in_other_languages|title=NetHack in other languages - NetHack Wiki|website=nethackwiki.com}}</ref> in German, Japanese, and Spanish.<ref name=":0" /> The license also allows for software forks as long as they are 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. This has also allowed source code forks of ''NetHack'' including ''[[Slash'EM]]'',<ref>{{Cite web|url=https://slashem.sourceforge.net/|title=The Slash'EM Homepage|website=slashem.sourceforge.net}}</ref> ''UnNetHack'',<ref>{{Cite web|url=https://github.com/UnNetHack/UnNetHack |title=UnNetHack|website=[[GitHub]]|date=21 October 2021}}</ref> and ''dNethack''.<ref>{{Cite web|url=https://github.com/Chris-plus-alphanumericgibberish/dNAO |title=dNethack|website=[[GitHub]]|date=21 October 2021}}</ref>

==Online support==
Bugs, humorous messages, stories, experiences, and ideas for the next version are discussed on the [[Usenet]] [[newsgroup]] rec.games.roguelike.nethack.<ref>{{Cite web|title = Nethack: The Best Game on your Mac|url = https://www.engadget.com/2007/05/20/nethack-the-best-game-on-your-mac/|website = Engadget| date=20 May 2007 |access-date = 2015-11-09}}</ref>

A public server at nethack.alt.org, commonly known as "NAO", gives players access to NetHack through a [[Telnet]] or [[Secure Shell|SSH]] interface. A browser-based client is also available on the same site. Ebonhack connects to NAO with a graphical tiles-based interface.<ref>{{Cite web |url=http://junction404.com/#ebonhack |title=Ebonhack webpage |access-date=4 May 2010 |archive-url=https://web.archive.org/web/20100512080207/http://junction404.com/#ebonhack |archive-date=12 May 2010 |url-status=dead}}</ref>

During the whole month of November, the annual /dev/null NetHack Tournament took place every year from 1999 to 2016.<ref>{{Cite web|title = GameSetWatch COLUMN: @Play: Ten Years of the devnull Nethack Tournament, Part 1|url = http://www.gamesetwatch.com/2008/10/column_play_ten_years_of_the_d.php|website = www.gamesetwatch.com|access-date = 2015-11-09|archive-date = 13 January 2016|archive-url = https://web.archive.org/web/20160113135436/http://www.gamesetwatch.com/2008/10/column_play_ten_years_of_the_d.php|url-status = dead}}</ref><ref name="tnnt-about">{{cite web |title=TNNT: About |url=https://www.hardfought.org/tnnt/about.html |website=The November Nethack Tournament |access-date=26 November 2020}}</ref> The November NetHack Tournament, initially conceived as a one-time tribute to devnull, has taken place each year since 2018.<ref name="tnnt-about" /> The Junethack Cross-Variant Summer Tournament has taken place annually since 2011.<ref>{{cite web|title=Junethack|url=https://junethack.net/|access-date=20 August 2016}}</ref>

==NetHack Learning Environment==
The [[Facebook]] [[artificial intelligence]] (AI) research team, along with researchers at the [[University of Oxford]], [[New York University]], the [[Imperial College London]], and [[University College London]], developed an open-source platform called the NetHack Learning Environment, designed to teach AI agents to play ''NetHack''. The base environment is able to maneuver the agent and fight its way through dungeons, but the team seeks community help to build an AI on the complexities of ''NetHack''{{'s}} interconnected systems, using implicit knowledge that comes from player-made resources, thus giving a means for programmers to hook into the environment with additional resources.<ref>{{cite web | url = https://venturebeat.com/2020/06/25/facebook-releases-ai-development-tool-based-on-nethack/ | title = Facebook releases AI development tool based on NetHack | first = Kyle | last = Wiggers | date = June 25, 2020 | access-date = June 26, 2020 | work = [[Venture Beat]]}}</ref><ref>{{cite journal | title = The NetHack Learning Environment | first1 = Heinrich | last1 = Küttler | first2 = Nantas | last2 = Nardelli | first3= Alexander H. | last3 = Miller | first4= Roberta | last4= Raileanu | first5= Marco | last5=Selvatici | first6= Edward | last6= Grefenstette | first7= Tim | last7= Rocktäschel | arxiv = 2006.13760 | journal = [[Machine Learning (journal)|Machine Learning]] | date = 2020}}</ref> Facebook's research led the company to pose ''NetHack'' as a grand challenge in AI in June 2021,<ref>{{cite web |title=Launching the NetHack Challenge at NeurIPS 2021 |url=https://ai.facebook.com/blog/launching-the-nethack-challenge-at-neurips-2021/ |access-date=5 September 2022}}</ref> in part due to the game's permadeath and inability to experiment with the environment without creating a reaction. The competition at the 2021 [[Conference on Neural Information Processing Systems]] involved agents of various designs attempting to ascend. None of the agents managed this; the results were ranked by median in-game score, with the highest-ranked agent (Team AutoAscend) using a symbolic (non-machine-learning) design.<ref>{{cite web |title=The NetHack Challenge: Dungeons, Dragons, and Tourists |url=https://nethackchallenge.com/report.html |access-date=5 September 2022}}</ref>

==Legacy==
''NetHack'' has influenced ''[[ADOM]]'',<ref>{{Cite web |last=Harris |first=John |date=November 19, 2018 |title=@Play 86: Interview with ADOM Creator Dr.Thomas Biskup |url=https://www.gamedeveloper.com/design/-play-86-interview-with-adom-creator-dr-thomas-biskup |access-date=2025-02-23 |website=Game Developer |language=en}}</ref> ''[[Minecraft]]'',<ref>{{Cite web |last=Knapp |first=Alex |date=2011-09-16 |title=Mojang Founders Notch and Jakob on Minecraft, Scrolls, and the Business of Indie Games |url=https://www.forbes.com/sites/alexknapp/2011/09/16/mojang-founders-notch-and-jakob-on-minecraft-scrolls-and-the-business-of-indie-games/ |url-status=live |archive-url=https://web.archive.org/web/20110923174319/http://www.forbes.com/sites/alexknapp/2011/09/16/mojang-founders-notch-and-jakob-on-minecraft-scrolls-and-the-business-of-indie-games/2 |archive-date=23 September 2011 |access-date=2025-02-23 |website=Forbes |language=en }}</ref> ''[[Spelunky]]'',<ref>{{Cite web |last=Harris |first=John |date=February 6, 2009 |title=@Play: 'Spelunk, Spelunk, Spelunk' |url=http://www.gamesetwatch.com/2009/02/column_play_spelunk_spelunk.php |url-status=dead |archive-url=https://web.archive.org/web/20090210103943/http://gamesetwatch.com/2009/02/column_play_spelunk_spelunk.php |archive-date=2009-02-10 |access-date=2025-02-23 |website=GameSetWatch}}</ref> ''[[Diablo (video game)|Diablo]]''<ref>{{Cite book |last=Waters |first=John K. |title=Diablo : the official strategy guide |publisher=Rocklin, Calif. : Prima Pub. |year=1997 |isbn=978-0-7615-0371-2 |pages=242 |url=https://archive.org/details/diabloofficialst00wate/page/242/mode/2up |url-access=registration}}</ref> and ''[[Mystery Dungeon]]''.<ref>{{cite web |url=https://www.famitsu.com/news/201406/08054671.html |access-date=August 2, 2021 |script-title=ja:すべては『ドアドア』から始まった――チュンソフト30周年のすべてを中村光一氏と振り返るロングインタビュー【前編】 |author=世界三大三代川 編集部 |date=June 8, 2014 |publisher=Famitsu |language=ja }}</ref> ''[[Time (Magazine)|Time]]'' included ''NetHack'' in its top 100 video games list in 2012.<ref>{{Cite web |last=Grossman |first=Lev |date=November 15, 2012 |title=All-TIME 100 Video Games: NetHack |url=https://techland.time.com/2012/11/15/all-time-100-video-games/slide/nethack-1987/ |url-status=dead |archive-url=https://web.archive.org/web/20121203004438/https://techland.time.com/2012/11/15/all-time-100-video-games/slide/nethack-1987/ |archive-date=3 December 2012 |access-date=2025-05-05 |website=Time Tech }}</ref> The game was part of the video game exhibit "Never Alone", in the [[Museum of Modern Art]]'s collection, which ran from September 2022 to July 2023.<ref>{{cite web |last1=Stanton |first1=Rich |title=Nethack is now in the Museum of Modern Art |url=https://www.pcgamer.com/uk/nethack-is-now-in-the-museum-of-modern-art/ |website=[[PC Gamer]] |publisher=[[Future plc]] |access-date=27 June 2022 |date=27 June 2022}}</ref>

==See also==
* [[List of open-source video games]]
* [[List of roguelikes]]

==References==
* {{cite book|last1=Craddock|first1=David L|editor1-last=Magrath|editor1-first=Andrew|title=Dungeon Hacks: How NetHack, Angband, and Other Roguelikes Changed the Course of Video Games|date=August 5, 2015|publisher=Press Start Press|isbn=978-0-692-50186-3}}

===Citations===
{{Reflist|30em}}

==External links==
<!-- Read external link policies before posting links here http://en.wikipedia.org/wiki/Wikipedia:External_links -->
{{Wikiquote}}
* {{official website|https://www.nethack.org/}}
** [https://www.nethack.org/v360/Guidebook.html A Guide to the Mazes of Menace (Guidebook for ''NetHack'')]
** [https://www.nethack.org/v360/downloads.html Download page for Official Binary and Source Releases]
** [https://nethack.org/common/git.html Info page for NetHack's public git repository]
* [http://www.nethackwiki.com The NetHack Wiki]
* [http://alt.org/nethack/ NAO website]
* [https://web.archive.org/web/20150910050253/http://nethack.devnull.net/ /dev/null NetHack Tournament]
* {{moby game|id=/nethack|name=''NetHack''}}
* [https://sourceforge.net/projects/nethack/ ''NetHack''] at [[SourceForge.net]]
* [https://web.archive.org/web/20120316213754/http://archive.gamespy.com/legacy/halloffame/nethack_a.shtm Hall of Fame – ''NetHack''] at [[GameSpy]]

{{Portal bar|1980s|Video games|Free Software}}

{{italic title}}

{{DEFAULTSORT:Nethack}}
[[Category:1987 video games]]
[[Category:Acorn Archimedes games]]
[[Category:Amiga games]]
[[Category:Android (operating system) games]]
[[Category:Atari ST games]]
[[Category:Cross-platform software]]
[[Category:Fantasy video games]]
[[Category:Free and open-source Android software]]
[[Category:Games with concealed rules]]
[[Category:GP2X games]]
[[Category:Linux games]]
[[Category:Classic Mac OS games]]
[[Category:Open-source video games]]
[[Category:MacOS games]]
[[Category:Roguelike video games]]
[[Category:Role-playing video games]]
[[Category:Video games with textual graphics]]
[[Category:Windows games]]
[[Category:Video games using procedural generation]]