Moving foreward as an adaptation of Rogue and Hack

Considering the fact that Rogue is public domain, Hack is BSD, and that I am not using any of the sources, and the deeper issues of other roguelikes which are in fact closed source, proprietary, and commercial (ex. ADOM, see genie in the bottle [local archive] and and many other discussions and interviews) it is pretty obvious the direction Netwhack is going to take regarding what kind of roguelike it is going to be. Simply put the inclusion of orcs and kobolds, for example, is not going to break anyone’s copyright restrictions, and if someone decides to sue me because a vampire appears in my game — well, they have the right to try but frankly I am not too worried about that.

The first step (Stage 1) in content development then would be to incorporate the main design elements present in Michael Toy’s paper which describes the operation of public domain rogue, while (possibly) keeping an eye on common design elements present in all or most roguelike games to avoid copying any one game by accident. From there I will have a look at some of what the BSD Hack 1.0.x sources have done, in terms of content addition, in order to bring the game up into a more full roguelike feel status. Code reuse or copying is out of the question not just from a moral or legal standpoint but from a practical one — It is important to note that I am not bothering to look at actual source code, nor would doing so really help. Strictly speaking even if I were to look at the source code just to see how the algorithms work to avoid copying them directly by accident (for, say, dungeon generation) it would not be applicable to my game since it uses wildly different data structures and simply operates in a different way (Object Oriented Java vs. 70s/80s Unix-style C code).

The remainder of this is sort of a part 4 to the previous posts which discusses ADOM and Dungeons and Dragons/AD&D and possibly some other fantasy RPGs and could be entitled “How I plan not to step on anyone’s toes but create a true and proper fully-authentic and immersive Roguelike game”.

Again though I bring up ADOM as a very interesting case. ADOM copies several elements of Nethack 3.1.x and up such as having various kinds of dragons represented by coloured uppercase ‘D’ such as ‘blue dragon’, various kinds of dogs represented by coloured lowercase ‘d’, such as ‘large dog’ (and ‘cute dog’ seemingly to match Nethack’s ‘little dog’), as well as many other obvious inclusions from the Nethack world*, for example:

  • Moloch is a demon in ADOM,
  • ADOM uses h to represent various kinds of dwarves,
  • Zombies (and skeletons and other) are lowercase z in ADOM, uppercase Z in nethack,
  • Werewolves and the more rare were-rat (d and r),
  • Water demons are blue ampersands,
  • Various kinds of trolls, uppercase T,
  • Various oozes and jellies (j),
  • Unicorns (U) vs u in Nethack,
  • Rust monsters (R), pit vipers (S/s), Ogres (O in both), including Ogre Lords and Ogre Kings,
  • Minotaurs (M), mimics (m), liches (L), floating eyes of various kinds (e),
  • Your various standard jackals, kobolds, including large kobold and kobold shaman,
  • Vortices including ice vortex and so on,
  • Orcs, including hill orcs and other kinds,
  • Worms (w), various elementals (E),
  • Bees (b) and ants (a),
  • Hill Giants, Stone Giants (H), Titans (H), Cyclops (H), fire giants, frost giants..
  • A few more.

Now the question is, did ADOM copy Nethack? Yes and no, hence the *. A lot of what is in Nethack is actually copied straight out of dungeons and dragons. Rothes for example are from the Forgotten realms. Or take the sunsword for example. The Sunsword is from various other fantasy settings (such as Dungeons and Dragons of course, again). Not to mention Thundarr the Barbarian, and several random novels (really) such as “The Sunsword Manual” and “Daniel and the Sun Sword”. Oh, and the NES version of Final Fantasy. Would using a Sunsword in my game break the NGPL? Obviously not. How about having an Excalibur? No, not any more than having Robin Hood’s Silver Arrow. It does not matter that Nethack included a silver arrow in one of it’s 3.x versions. For what it’s worth though I do not plan to include Excalibur, nor silver arrows per se. It’s an example to muse the point.

But back to D&D vs ADOM vs Nethack — the idea of orcs is nice, but hill orcs? Kobolds are nice, but also large kobolds, and kobold shamans, specifically? Granted that ADOM did not copy everything, and most of what it did seems available elsewhere (Hack, D&D, random fantasy novels and games) and granted that ADOM includes MANY many more unique monsters, some of the above with changed symbols and so forth, and does not include many common monsters such as newt, iguana and lizard, and while you can make an argument that ADOM copied Nethack, you can also make the argument that what they copied is basically common to all fantasy worlds, more or less. Ex. why all the same kinds of giants such as fire giants, and not other kinds of elemental giants such as wind giants?

What I find most interesting though is the similar symbols. Classifying an ooze as a jelly (j) reeks of the Hack codebase, and monsters such as titans, cyclops and hill giants all being H is basically just copying Nethack. Okay so there’s no storm giants and instead we have, say, Stone Giant Lords and Fomorian Giants. Okay, so I guess they’re not really copying Nethack then?

If the above is any clue, it is possible to include a great amount of the monsters in Nethack and use basically all the same symbols providing you include an equal or greater number of subtle changes and original monsters. Who owns the letter z? Zombies, Zruties, Nethack or ADOM? Sesame Street? Likely, nobody.

Granted, ADOM’s gameplay is wildly different from Nethack’s, despite the inclusion of select groups of monsters which seems to have been intentional. Question: Netwhack could (should) include a similar list of monsters to the above, but how many more is okay? Obviously the monsters will have different stats and combat works differently, I just find it interesting to see how far others have taken things in the hack-vs-nethack universe.

Iems in ADOM are different, I won’t go over scrolls for example other than to say, it’s really different besides common ideas like scrolls of identify.

Magic in general though is interesting. Of course there are spells, among them, fire bolt, magic missile, death ray/finger of death, fireball, heal, light, invisibility, slow, summon or create monster, and others — are common spells in Nethack and ADOM — although granted, each game also has many other spells not found in either game. This shows that there are many such spells one can ‘copy’ from Nethack when all one is really doing is including what’s common in the magical fantasy genre. The goal being not to copy Nethack of course, or ADOM, but to come up with a reasonable set of spells for a fantasy world that is ‘immersive’ in what people expect of such a fantasy setting.

Races? Humans, Elves, dwarves, gnomes and orcs. All the races in Nethack. Classes are another matter, the class system in ADOM is unique and original and if I may say so, stunningly awesome. However therein lies standards; Healers and Priests, Knights, Barbarians, Monks, Rangers, Thieves(Rogues), and of course Wizards. Notably absent are the original Tourist, Caveman and Speleologist/Archaeologist which would have been PD anyways. There are of course original additions such as Weaponsmith.

Again I note that while ADOM has clearly copied Nethack (why gnomes, dear lord, why gnomes) they have also clearly added large amounts of new material which defines and distances the ADOM world away from Nethack’s.

Alignment? Chaos, neutral and Law, just like Chaotic and Lawful (and Neutral) which is basically straight out of dungeons and dragons anyways.

Skills with weapons follow the exact same progression as well: unskilled, basic, skilled, excellent/expert, master/mastery, and grand master/grand mastery. Who copied who here is uncertain but it is clear that there are many shared game mechanics on the surface which are (obviously) implemented in different ways. I just note it would be reasonable to include such a system in a similar commerical, proprietary product, doing so would not be ‘copying’ or ‘using’ either product.

General Look and Feel

Nethack itself appears to change very little from Hack in terms of basic inventory management and display. ADOM is quite different although essentially the same in that inventory is represented by letters. The display status bar is two lines and shows name in the upper left, followed by stats, hit points, levels and experience as “Exp: 1/138″, stats, dungeon level, and so on, with a two-line message section at the top of the screen. This is the same in rogue and hack anwyays from what I recall. Versus rogue, ADOM uses % for food and < and > for stairs (Rogue used : for food and % for stairs), traps are ^, closed doors are + (open doors are /). In Netwhack, open doors are minus signs (I believe this may be the same as in Nethack, I can’t remember). In actuality, the symbols used by Nethack are able to be customized and may be different from build to build, so these are just generalities and not ‘copying’ one game or another — just copying the ‘genre’ apparently. # is a wall in ADOM where hack uses pipes and minuses and some versions (even of Rogue) use IBM CP437 Graphics.

Weapons, rings, armor, gold, scrolls, food, tools, potions and many other objects all use the same symbols across Hack, Nethack, Rogue and ADOM althouh there are some changes especially in ADOM such as books being ” instead of +.

The commands in Rogue, Hack and Nethack are all mostly similar, such as , for pickup and < and > for stairs. The commands in ADOM which are similar seem to be (among others) chat, use stairs, drop, eat, give, inventory, kick, open door, quit, read, save game, search, throw item, zap and a few others. SO it should be very clear the command interface can be reasonably familiar; again note that ADOM has many more special and unique commands and some seem to be different than rogue/hack/etc. Gotta put your own spin on things I guess.

There shouldn’t be any complaint in the look and feel department.


It seems that allowing the user to customize their command key layout and their symbols shown is the best way to avoid any problems with completely copying anything while still allowing the user to get what they want out of the game the way they want/expect to play it. Netwhack has already developed many of its own idiosyncracies of course, in how it displays levels. There are no red carpets in ADOM or Nethack that I am aware of, for example.

The Way Forward

In addition to approximating what is put out in the Rogue manual for Public Domain rogue, it appears as if we may deign to throw in certain kinds of content which appear in Nethack, so long as it appears in other games, even proprietary closed source commercial games, and/or to the point where what ever is copied is done so in a reasonable manner (I.E. orcs, hill orcs and hill orc captains, all seem to be fair game, so long as we also incude.. say… fire orcs and fire orc mages) and so long as we also leave out certain other key things such as, say, zrutys (what the heck is a zruty anyways?)

This may also be an opportunity to distinguish Netwhack apart from other roguelikes which may over time have become somewhat cartoonish and ridiculous in their appropriation of cultural tropes that most people would find alien to the common fantasy setting. Not naming anything in particular; but Netwhack could be positioned as a product with a higher level of fantasy, a more serious and immersive world, than other roguelikes, while maintaining a classical look and feel within acceptable limits (rogue, hack, and further customization available to the user). Thus I think I could position Netwhack as a more serious and interesting game than certain other roguelikes. A noble goal! We shall see how it plays out.

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