The NetHack General Public License allows anyone to create a variant, provided that they use the same license. Then, features from that variant may be reused in vanilla NetHack (under a small chance) or in another variant!

A variant typically contains many more changes to the game than a patch. A variant is either distributed as a very large patch against vanilla NetHack, or as a separate source code distribution.


Variant Description

Slash'EM or SLASH'EM, officially SuperLotsaAddedStuffHack - Extended Magic, is the most famous variant. This game and its ancestor variants are now part of vanilla NetHack's game history, because of the reuse of certain SLASH'EM code into NetHack 3.3.0. Perhaps because of this, and because so many players busy themselves with vanilla, SLASH'EM and other variants may have less attention than they had previously.

SLASH'EM puts more effort (than vanilla) into killing the hero; plenty of games end at Dlvl1. There are more than plenty of new monsters, items and magic. The dungeon features several new one-level dungeon branches for lose the hero in. Three new portals lead to quests for artifact keys. The player also has a larger choice of races and roles than in vanilla, and that alone is enough to make an experienced NetHack player rethink strategy.

SLASH'EM started as a combination of two other variants, SLASH and the Wizard Patch. In turn, SLASH was a merger of and addition to NetHack Plus and NetHack--. Work continues on merging the Lethe patch into SLASH'EM.

SporkHack is a variant no longer under active development; it aims to bring more challenge to the vanilla game for experienced players, as well as to make things less boring for _all_ players. Derek Ray maintains a telnet server at so that players need not compile or install the game. A patch and a Windows binary are available from the home page; the patch can be applied to a standard Nethack 3.4.3 distribution. SporkHack contains "more interesting" Caveman and Knight roles (including the Dark Knight), a number of new monsters, modified more-useful artifacts, and a number of balance adjustments throughout the game to special levels (Orctown), spells, monsters and items... as well as features typically obscured from the player, such as the "to hit" formula. There are also cosmetic changes; for example, the master lich is a green L.

Creator's note: players interested in Sporkhack's changes but looking for a live-development fork are suggested to look into UnNethack; many of the changes and new items have been brought over and merged by Patric over that variant's dev process.

UnNetHack 4.0.0 is a variant of NetHack 3.4.3, maintained by Patric Mueller and others. The main intent of this fork is to put more randomness, challenges and fun into NetHack. UnNetHack incorporates many improvements from other variants and patches made by the community.

It features more levels, several UI improvements, and a lot of game play related changes. There is a public server at

GruntHack is distributed as a patch of over seven hundred kilobytes and extends the game in multiple ways. Much of it is adding behavior to existing things, rather than adding new things. For example, objects of the same object type can be made from different materials and monsters can have different races. Monsters can now use more tactics when fighting other monsters; pets can become full and stop eating.

Some of the changes are similar to those in SLASH'EM or in NetHack brass, but GruntHack takes a different direction from either.

Coming from Japan, NetHack brass is lesser known among NetHack players who do not speak Japanese. The game is in English but most of the community uses Japanese. NetHack brass adds no new races or roles, but it has a few new items and a redesigned Gehennom. Its major features include the new #skills system and tweaks to how heroes gain experience levels and attributes. Minetown is now filled with shops, while the top of Sokoban offers prizes but permits the player to choose one and only one.

Despite the many changes in this variant, they do not feel so drastic, and NetHack brass feels more like vanilla than the other variants.

The biodiversity patch adds several monsters to the game, adjusts some monster behaviors and adds a few other features. This patch is about populating the dungeon with monsters, not about changing the dungeon. It even adds more trees.

Some of the changes have basis in reality (like echolocation for bats), but there are also some serious nasties, including the disintegrator and the goldbug.

The Lethe patch seems to be only a minor change to the game, before you reach Medusa. There you find the River Lethe which leads you into a very different Gehennom.

There are many new scares down there. If you are sufficiently powerful, then you can fight through it all, but it will far more difficult than the boring and relatively benign mazes of vanilla. Type carefully, and do not step into the river that causes amnesia. At Moloch's Sanctum, the high priest of Moloch is Cthulhu...

These days, more players choose SLASH'EM 0.0.7E7, which has most of the new items and monsters from this patch, but not the changed levels. Until the levels are integrated, one can play SLethe which includes the new levels. There is a 0.0.7E7F2 SLethe playground on

NetHack: The Next Generation was a variant that has mostly fallen into disuse. TNG contains several strange new monsters and items, but is mostly remembered for the Geek class and the Douglas Adams themed monsters.

There are some Japanese variants missing from the above list.

You can also mix multiple patches, large or small, to form your own variant. You can select patches from the Patch Database or L's collection – beware of conflicts and rejected hunks if you apply multiple patches!