NetHack

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 of the 1984 game Hack, itself inspired by the 1980 game Rogue. The player takes the role of one of several pre-defined character classes to descend through multiple dungeon floors, fighting monsters and collecting treasure, to recover the "Amulet of Yendor" at the lowest floor and then escape.