Hack was created in 1982 by Jay Fenlason with the assistance of Kenny Woodland, Mike Thome, and Jonathan Payne, while students at Lincoln-Sudbury Regional High School. A greatly extended version was first released on Usenet in 1984 by Andries Brouwer. Brouwer continued to work on Hack until July 1985. Don Kneller ported the game to MS-DOS and continued development there. Development on all Hack versions ended within a few years. Hack descendant NetHack was released in 1987.
Hack is still available for Unix, and is distributed alongside many modern Unix-like OSes, including Debian, Ubuntu, the BSDs, Fedora, and others. Hack has also been ported to a variety of non-Unix-based platforms. NetHack is available for almost all platforms which run Hack. There is one exception: Hack is available, but NetHack is unavailable, for the Game Boy Advance.
This describes Brouwer's version 1.0.3, which is the most canonical version, being the one installed by package managers on Linux systems.
Being developed by one man means the game is balanced. Even when you have discovered all properties of monsters, wands, potions, and have fathomed the role of "luck", the game remains as playable as ever. It may take ages before you reach that stage. You're helped by rumors: cryptic hints, hidden in fortune cookies.
The object of the game is to delve into a dungeon to retrieve the Amulet of Yendor, and perish with as much game points as possible. The player can start out with a different ability set, such as Wizard or Cave(wo)man. The player confronts various monsters: hobgoblins, leprechauns, acid blobs, bats, centaurs, chameleons, dragons, ghosts, imps, trolls, and has weapons, armor, potions, wands, rings and special items to aid in this, e.g. related to fire there is a scroll, a ring, a monster and a wand, and their interplay is to be discovered.
There is time pressure because you die if your food runs out, food is scattered around the dungeon. There is a limit to what you can carry, forcing you to leave valuable items behind. The gold and gems you carry when you die increases your score, but it is heavy too.
The player must enter Hell to recover the Amulet. Entering Hell for the uninitiated just means that "you burn to a crisp". (In NetHack, Hell is renamed.)
The player encounters special rooms such as shops, crypts, and vaults. Other spatial elements in the game are traps and swamps. As your experience grows, so do your abilities, score and the need for food.
Retrieving the Amulet doesn't guarantee you the high score. After all the Amulet is just a very valuable gem.
Hack implements a graphical user interface using arrangements of ASCII or Extended ASCII glyphs to represent game elements. Some later ports of Hack, on AmigaOS for example, use graphical tiles in place of these letters and symbols.
Key:@ - the player character
+ - a door
$ - gold
% - food
L - monster; a leprechaun
[ - armor
# - corridor
< - stairway leading upwards