DynaHack

NitroHack's engine, UnNetHack's dungeon · less tedium, more variety

Date of birth18 September 2013 first public release 0.5.0 (work in git from March 2012); this version 0.6.0: 17 February 2016

CreatorsTung Nguyen (tungtn) on Daniel Thaler's NitroHack, with UnNetHack's content (Patric Müller et al.)

LanguageC ~147,500 lines in 166 libnitrohack/src/*.c/include/*.h files

PlatformLinux, Windows, OS X curses terminal client; here: the browser

Lineage

DynaHack sits on NitroHack, Daniel Thaler's 2011 rewrite of NetHack 3.4.3 into a game library (libnitrohack) plus a separate curses client, with a new save format, key remapping and in-game options. Tung Nguyen started in March 2012 by porting UnNetHack (Patric Müller's NetHack 3.4.3 variant) onto NitroHack 4.0.4; the working name was “UnNitroHack”, never released under that name. By 0.5.0 it had its own name and had picked up changes from NetHack4, GruntHack (magical equipment), UnNetHackPlus (monster descriptions) and K-Mod, plus its own.

NetHack4 is a sibling, not a parent: it also grew out of NitroHack, and DynaHack ported selected changes from it. Sources: doc/changelog.txt (0.5.0 entry), doc/unnitrohack.txt, doc/nitrohack.txt and the git history. See the family tree, under NitroHack.

Credits

Tung Nguyen (tungtn)	Created and maintained DynaHack, 2012–2016 (1,268 commits)
Daniel Thaler	NitroHack: library/client split, log-based saves, the curses interface (748 commits in the shared history)
Patric Müller and the UnNetHack contributors	UnNetHack 4.1.1, the source of most new levels, branches, items and monsters
Alex Smith, Sean Hunt	NetHack4, source of ported interface and reliability changes (`[NH4]` in the changelog)
GruntHack, UnNetHackPlus, K-Mod authors	Random magical equipment, monster spoiler info and other ported changes (`[Gr]`, `[UnP]`, `[KMd]`)
The NetHack DevTeam	NetHack 3.4.3, the code underneath
This port	Browser client and build, tiles from the NetHack 3.4.3 set (memmaker/dynahack)

Trivia

Its working name was “UnNitroHack”: the plan was UnNetHack on a NitroHack base. (NetHackWiki)
It is based on NitroHack 4.0.4 of 19 February 2012. (NetHackWiki)
The release dates disagree by a few days: NetHackWiki and the changelog give 18 September 2013 for 0.5.0, RogueBasin 22 September 2013 (and 18 February 2016 for 0.6.0). (RogueBasin)
0.6.0 was the last release: the author wrote he would no longer work on DynaHack and asked for bug reports as GitHub issues instead of email. (GitHub README)
It can still be played online on hardfought.org. (NetHackWiki)
RogueBasin lists it as a “Beta Project” and puts a game at 8+ hours. (RogueBasin)
Dragons are shuffled every game: a red dragon may be a tatzelworm breathing ice in one game and a draken breathing disintegration in the next. (GitHub README)

What's unique

The NitroHack interface (the README's “advanced ASCII interface”): resizing, a multi-line message box, an inventory sidebar, HP/Pw bars, item action menus, remappable keys and options set in-game. Ctrl-O shows the dungeon overview, Ctrl-X your resistances, Ctrl-E engraves Elbereth, v auto-explores and _ travels (it routes around peacefuls and works in Sokoban). All are commands in cmd.c.
Magic chests: whatever you put in one can be taken out of any other, at fixed spots (e.g. next to the Mines altars in mines.des), so no stash trips.
Random magical equipment from GruntHack: any weapon, armour, ring or amulet can carry properties such as fire, frost, drain life, vorpal, reflection, speed, stealth or detonations (ITEM_* in obj.h). The starting kit itself follows NetHack's role lists.
UnNetHack's dungeon: over 80 new special levels, Gehennom without mazes, new branches Town, One-eyed Sam's Market, the Dragon Caves and the Advent Calendar; tin shops, instrument shops, pet stores; iron safes, tinfoil hats, the scroll of flood; the Convict role and the vampire race.
Rule changes: color alchemy (potions mix by colour), wishes for magical items only from a wand of wishing, partial resistances from corpses, delayed instead of instant petrification, poison drains max HP instead of killing, armour and shield skills, cross-training weapon skills and “heavyshot” for crossbows and thrown spears.

Code dive

Language: C (gnu99-ish, K&R roots): 147,539 lines in 166 files under libnitrohack/src and libnitrohack/include at upstream commit 25aaf2a; built with CMake.
Platforms: Linux and OS X natively, Windows with MinGW or Cygwin (doc/build-*.md); a dgamelaunch guide for servers.
Library and client: the game is a library with a small API (include/nitrohack.h): the client passes in a struct nh_window_procs (display callbacks) and drives the game with nh_command(). Commands and item actions come from the library (nh_get_commands(), nh_get_object_commands()), so a client needs no command table of its own.
The save is a log: the .nhgame file holds the random seed and every command, written as you play, plus a binary snapshot. A crashed game is restored by replaying the log (logreplay.c); finished games stay viewable as replays.
Data tables: monsters in monst.c, objects in objects.c, artifacts in artilist.h, roles and races in role.c; levels in dat/*.des (lev_comp) and the layout in dat/dungeon.def (dgn_comp).
Our port: a browser client web/webwin.c (~1,300 lines) replaces the curses client; the library is almost untouched (auto-explore stops on new messages and avoids boulders, </> walk to stairs). The data tools run as wasm under node because wasm32's 4-byte long changes the file headers. The log save lives in IndexedDB, so a closed tab is replayed to the same turn.
Source: memmaker/dynahack; upstream tung/DynaHack @ 25aaf2a; our changes.

Stats

Counted in the source at 25aaf2a (objects: named entries per class from the object table, 538 slots in all).

Thing	Count	Notable ones
Roles	14	NetHack's 13 plus the Convict, who starts in a striped shirt with a rock, nearly hungry and hated by their own race; the quest leader is Robert the Lifer, against Warden Arianna.
Races	6	Human, elf, dwarf, gnome, orc and vampire.
Monsters	403	Eleven dragon kinds with shuffled names (tatzelworm, draken, guivre…), the gold dragon, the vorpal jabberwock, the rodent of unusual size, the disintegrator, the wax golem, the black marketeer, Cthulhu, and Death, Pestilence and Famine.
Artifacts	36	Thiefbane and the Luck Blade (from UnNetHack), Stormbringer, Vorpal Blade, the Iron Ball of Liberation (the Convict's quest artifact).
Spells	40	Create familiar, stone to flesh, jumping.
Weapons / Armour	71 / 85	Chromatic and magic dragon scale mail, crystal and bronze plate mail, the striped shirt, the tinfoil hat.
Rings / Amulets	31 / 11	Rings of gain intelligence, wisdom and dexterity.
Tools	51	Iron safe, ice box, oilskin sack; land mine and beartrap as items. (The magic chest is a map feature, not an item.)
Potions / Scrolls / Wands	28 / 22 / 24	Potions of blood and vampire blood; the scroll of flood replaces amnesia.
Food / Gems	29 / 36
Traps	24	Shuriken trap; the vibrating square counts as one.
Dungeon	12 dungeons	Dungeons of Doom and Gehennom 25–29 levels each, Gnomish Mines 8–9 (8 Minetown variants), the Quest 5–6, Sokoban 3, Town 3 (with the nymph level), the Dragon Caves 4 (75% chance), Vlad's Tower 4, Elemental Planes 6, Fort Ludios, One-eyed Sam's Market and the Advent Calendar 1 each; 184 level maps in `dat/*.des`.

Manual

DynaHack ships NetHack's own Guidebook (NetHack 3.4.3 edition, text, converted from doc/Guidebook.tex), never updated for DynaHack. What DynaHack changes is in its changelog (0.5.0 to 0.6.0). Both under the NetHack General Public License. The in-game ?? command reference and the port's help page cover the keys.

Getting started

Open the game, pick role, race, gender and alignment from the menus (or Random) and type a name. A Valkyrie or Samurai forgives mistakes.
Move with the arrow keys or hjklyubn; walk into a monster to attack.
Press v (or ~) to explore, again after each stop; when the level is done, > walks to the down stairs.
Enter opens a menu of every command, i the inventory with an action menu per item; Ctrl-O shows the dungeon overview.
In trouble, Ctrl-E writes Elbereth or #prays if you haven't lately; the full key list is in the in-game guide.

Help

There is no walkthrough for DynaHack. NetHackWiki's DynaHack page lists its differences, and the vanilla Standard strategy mostly applies. Rules of thumb from the README:

Level difficulty depends on depth only, not your experience level: don't dive faster than your gear allows.
Don't count on a dragon scale wish: dragon names and breath are shuffled, and only a wand of wishing grants magical items.
Elbereth doesn't scare quest nemeses, unique demons or Vlad.
Look for magical properties on ordinary gear; it can fill an ascension-kit slot.
Use magic chests instead of carrying things back to a stash.
More: NetHackWiki: UnNetHack (most of the content), RogueBasin, the DynaHack home page.

Cheats

Wizard, explore and tutorial mode are start modes of the library (nh_start_game(…, MODE_WIZARD)), picked in the curses client. Our browser client always starts MODE_NORMAL, so none of them is reachable here, and there is no in-game #explore.
Save scumming works: Export save downloads the game log; Import save loads it back. Since the save is a replayed log, importing an older export rewinds the game to that point.
No exploits are listed here: none were checked on a fetched page.