NetHack

Before starting a game, players choose their character's race, role, genre, 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 roles, including archaeologist, tourist, and caveman. 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.

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.

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 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. 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 programming hack.

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. 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.

NetHack has influenced ADOM, Minecraft, Spelunky, Diablo, and Mystery Dungeon. Time included NetHack in its top 100 video games list in 2012. Other publications listing it among the best video games include 1001 Video Games You Must Play Before You Die (2013, 1001-game list), Digitally Downloaded (2016, 63rd in a 100-game list) and Polygon (2017, 87th in a 500-game list). 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. NetHack was also included in a list of the best open source video games by The Gamer.