NetHack
(from nethack.txt:)
NetHack is a display oriented Dungeons & Dragons(tm) - like game. The standard tty display and command structure resemble rogue.
Other, more graphical display options exist if you are using either a PC, or an X11 interface.
To win the game (as opposed to merely playing to beat other people's high scores) you must locate the Amulet of Yendor which is somewhere below the 20th level of the dungeon and get it out. Nobody has achieved this yet; anybody who does will probably go down in history as a hero among heros.
When the game ends, whether by your dying, quitting, or escaping from the caves, NetHack will give you (a fragment of) the list of top scorers. The scoring is based on many aspects of your behavior, but a rough estimate is obtained by taking the amount of gold you've found in the cave plus four times your (real) experience. Precious stones may be worth a lot of gold when brought to the exit. There is a 10% penalty for getting yourself killed.
Source:
Unknown Source
Contributed by Droog.