User:Ais523/Dungeon Overhaul Proposal
Note: There are some parts of this proposed dungeon that were omitted, such as the Wizard's Tower, simply because they were forgotten about. Readers of the proposal assumed that they work reasonably similarly to vanilla.
- 1 Introduction
- 2 Dungeons
- 3 The Gnomish Mines
- 4 The Minigame Branches
- 5 The Quest
- 6 The Maze
- 7 Gateway
- 8 The Tower of Madness
- 9 Gehennom
- 10 Eternity
- 11 The Tower of Silence
- 12 The Surface
- 13 The Elemental Planes
- 14 And finally...
We were originally planning to have a competition with respect to dungeon redesign. That's rather fallen by the wayside, but that doesn't mean that we nonetheless can't write submissions for it and discuss it unofficially. Here's my plans for what the NetHack dungeon could ideally look like.
The "main branch" throughout the early game and mid game is, as before, the dungeons. These are entered via stairs from the surface, and where the player starts the game proper. The level generator for this is fine; it could be improved but isn't bad at the moment, and an improvement would likely just be for visual variety rather than aiming to substantially change the problems that the level design poses. I would, however, substantially reduce or remove the probability of dead ends generating early; they aren't that interesting and can lead to problems when adding monsters that the player isn't meant to fight (as a dead end may mean they have no option).
As before, the Dungeons have various special levels scattered throughout them (in addition to branch entrances, which are considered separately below):
The Oracle remains in the game, but with a tightened (and shallower) level range; her level always appears as level 5 or 6. The purpose is the same as before, to give a milestone in the very early game (which should show in the xlog, please!), to provide a method of giving information to unspoiled players, and to serve as a location for lawful players to make many attempts at getting Excalibur if they wish.
The big room is now guaranteed, but has a much wider depth range (being able to appear anywhere between the Oracle and Medusa); it's interesting pretty much wherever it shows up, so varying the depth is a good way to preserve the variety that's currently given via the chance of it not generating, but needs to be on the main branch to force the character to go through it (there's no reward so it wouldn't be worth doing otherwise, and this seems like a better option than adding one). The most interesting/fun variants are those which are very open and have few obstacles to vision, (such as the lit-rectangle and elliptical variants), so those should be favoured in the rotation. (Perhaps there should be other variants too that fit this description, such as a room with tiny, regularly-spaced pillars.)
The rogue level is an amusing and pleasantly surprising thing to have in the game, and worthwhile on that basis, but its actual gameplay isn't all that different from regular gameplay. Unlike most special levels, it also doesn't really serve as a milestone. As such, the rogue level now only generates in a small proportion of games (maybe 20%), and is otherwise unchanged; that should make it more surprising when it turns up.
Fort Ludios is similar to previous versions, being a one-level branch accessed via a magic portal in a vault somewhere in the lower half of the Dungeons. Because it's already a place that many players find fun to visit but can be safely skipped, it'd be worth trying to increase the probability with which it generates, ideally to 100% (I know there are technical issues with this but they're likely resolvable).
The general idea of the map works pretty well (although I'd probably change the entrance room, which is one of the most awkward sizes it could be; it needs to either be a corridor or else to drop the player in open space). As usual, being able to make the details slightly random would be a good thing, although it's a lower priority here than elsewhere.
One change which I think would be very worthwhile would be to change the Minesweeper reference to an actual Minesweeper minigame. This could be done via changing the sizes of the stacks of gold to reflect the number of adjacent mines (and placing mines so that every square had an adjacent mine and so that every square was reachable without stepping on mines). The mines themselves would be undetectable except by stepping on them, triggered automatically when stepped on or hovered over, and covered by a single gold piece. Triggering any mine would cause the remaining gold in the treasure room to fall through cracks in the floor, giving a big incentive to solve the puzzle rather than just tanking the traps. We'd need to give a hint as to how all this works (probably via both Oracle consultation and an engraving outside the room itself).
Note that there's been a suggestion in #nethack4 that a reference to the Infocom text adventure games in NetHack would be desirable, but preferably a really subtle one (that's more interesting than just adding hallucinatory monsters). I'm informed that many such games used the number 69105 somewhere as an easter egg, and it struck me that the total number of gold pieces in the Ludios treasure room is of around that magnitude as it is; we might want to make it a constant 69105 in order to continue the reference.
More special levels?
The deeper Dungeons could probably do with other special levels which change up the "feel" of the gameplay somewhat without fundamentally changing the actual strategic rewards. (The Rogue Level is a good example of this.) In other words, you go through them on the way down and again on the way up, but probably don't trawl through them repeatedly all that offen. If the level requires the player to learn/understand how it functions in order to play properly, it should probably be in every game so that unspoiled players can figure out how it works over time. If it doesn't, it should probably generate with only a small probability to help maintain the novelty.
The last level / branch ending of the Dungeons is now Medusa's Island. This has similar considerations to existing versions of NetHack, serving (in terms of the feel of the dungeon) as an obvious landmark location, and (in terms of strategy) as an "item test" that requires the player to deploy a means of crossing water (at a point in the game which is early enough that they may well not have a permanent source, and thus need to use consumables). The level is predominently formed of water, with several islands, some of which contain ruined buildings. There's now guaranteed to be a path from the stairs to Medusa's island itself that doesn't cross any more than two water tiles in one go; this means that a character crossing using jumping boots doesn't have to worry about the instadeath caused by colliding with a monster after two squares of a three-square jump.
Ideally, the level would be randomly generated, rather than using fixed special-level maps, although keeping to the same general principles as the existing levels. The titan in one variant is probably overkill (it's interesting but this is the wrong level to put it on; I'd recommend moving it elsewhere or removing it).
Guaranteed items in the level include a blessed potion of monster detection on the entrance island (as an additional clue to Medusa's presence for people who think the inclusion of Medusa in the game is unfair to unspoiled players, and as a way for experienced players to check the locations of sea monsters; note that the item could also come in handy later, so there are definitely reasons to not use it), a number of statues in the room prior to Medusa herself (the existing clue that there's a petrifying monster going around), and the statue of Perseus in Medusa's room itself. The statue is now guaranteed to contain a sack, and either a shield of reflection or cursed boots of levitation.
Medusa herself is the same as before, staying in a room with closed doors and guarded by squeaky boards. (For flavour, can we give them a sound other than the usual ones? In 3.6.0, most squeaky boards play musical notes; making these hiss or something could be interesting.) She's no longer alone in her room, having a retinue of fairly weak snakes (for flavour reasons; the player's unlikely to have much trouble killing them).
This level can be left, entering the first level of the Maze, using a branch ladder in Medusa's room (which is as usual two-way, also making it possible to climb up from the Maze to the Dungeons). It's also possible to dig down through the floor (when not adjacent to water), likewise ending up in the Maze. Holes and trapdoors do not naturally generate on the level, so the player will only fall as a consequence of digging down themselves (or frightening a monster into doing it for them).
The Gnomish Mines
Just like at present, the Mines have the shallowest entrance of any optional branch; the branch stairs are on Dungeons:2-4, making the first level of the Mines one of Mines:3-5.
The mines filler levels are not that different from in existing versions of NetHack. One change is that the mines have no natural light at all; rather, the light predominantly comes from a type of glowing fungus (in ASCII, bright cyan F would make sense as a symbol; and "luminescent fungus" would do as a name) which illuminates an area around it. The fungus also gives poison resistance when eaten (with a fairly low probability), tempting players to darken the area. The gnomes generate with candles (as in 3.6.0 and many NetHack variants), to ensure that making the game unwinnable via candle shortage takes ridiculous effort (i.e. is only likely to be done intentionally), and for flavour reasons too. (It'd be nice if the gnomes could use the candles, but that's been shown to have unworkable logistical problems due to inventories getting cluttered with many candles of different lengths. Additionally, it would be nice if the player could viably use the candles as a light source, meaning they probably need a longer burn time. Perhaps the best option would be to have just a few statuses for candle length: "long candle", "short candle", "candle stub", with each length having a very small random chance of going to the next length down (or burning out if a stub) every turn it's lit?)
Some other minor changes are to tweak the dungeon generator slightly to reduce the chance of chokepoints (they tend to be tedious in the common case), and to change the monster AI so that peaceful gnomes become hostile if they see you attack a peaceful gnome (the current behaviour feels jarringly unrealistic).
Mines filler levels below Minetown are broadly the same as those above, but contain less luminescent fungus. Additionally, levels of gold and gems in the branch as a whole are similar to 3.4.3, but bottom-weighted (i.e. less generating at shallower depths, more generating at deeper depths). There's also a guaranteed, pre-identified polymorph trap on one of the shallower filler levels in the lower Mines (in addition to the possibility of secret polymorph traps anywhere they're in-depth); the idea is that the polymorph trap adds both danger to the level, and serves as a minor reward once cleared.
Minetown is generally similar in nature to 3.4.3, containing several shops, an attended temple, and watchmen with a watch captain. (Orctown has proven to have been very unpopular/unenjoyable.) The shopping situation now consists of two guaranteed shops (Izchak's lighting store and a delicatessen) plus two random shops. All the shops are, however, fairly small, with an initial stock of maybe 6-12 items.
The temple still exists, but now always has a neutral altar. (It seemed flavourly appropriate to have an altar that gnomes would use, and having guaranteed alignments for the early-game altars helps to differentiate characters from each other a bit more strongly.)
It might be interesting to see if it's possible to generate Minetown layouts similar to 3.4.3's randomly. Extra variety would not be a bad idea in this case, because what's important is what the level contains, not that the player recognises the layout.
The Catacombs has changed from being a Mine's End variant to a guaranteed (but short) branch in its own right. It's a single level accessed via downwards branch stairs somewhere near the bottom of the Mines (from one of the last two filler levels). The level has a similar (but not identical) layout to previous versions, consisting of a small number of randomly placed medium-sized (but not identically-sized) square rooms, with the area outside the rooms filled with semimaze (i.e. a locally mazelike structure which globally has multiple paths from place to place; think of a maze where gaps are made in the walls in order to ensure that no two points are too far apart following corridors). There's no luckstone here; rather, the level contains (as before) a number of spellbooks randomly scattered around.
The level continues to be populated by undead. (It can also generate slightly to moderately out-of-depth undead, but only rarely, and only if they move more slowly than the player does.) The staircase (the only stairs on the level, as it's effectively a "branch end") is in one of the rooms; a different (randomly chosen) room is the throne room of Vlad the Impaler, who has identical stats to 3.4.3 apart from no longer being covetous. Vlad has no special death drops himself, but his throne room's throne chest contains two guaranteed cursed scrolls of teleport, in addition to three random scrolls and typical chest inventory. Unfortunately, the chest is situated on a level teleporter (as a reference to the level teleporters beneath the gray stones in the 3.4.3 version of the map). Vlad is aware of the level teleporter and will not step on it voluntarily.
The throne room also, of course, contains a throne; this is a special throne that always gives a full ID of inventory the first time it's used, without vanishing (future uses give random results and can vanish, i.e. it turns into a normal throne after being used once).
The basic idea of this branch is to be a way for spellcasters to get properly started with their spellcasting, whilst having rewards large enough that they don't feel like a waste to get even for non-spellcasters, but small enough that skipping the branch doesn't leave you missing out on anything you badly needed. I also wanted to give Vlad somewhere to live where he could actually be somewhat scary.
The idea of Mines' End in vanilla is reasonable enough, but the actual set of maps needs quite some review. The Gnome King's Wine Cellar is good enough as levels go (although could do with being less hardcoded), but the Mimic of the Mines is fairly tedious and unrewarding, and the Catacombs is out of place (and thus moved to a separate branch here).
As such, what Mines' End really needs is more layouts, loosely based on the Gnome King's Wine Cellar. That means a reward of a luckstone, several highly valuable gems available (but unidentified), probably some decoy loadstones, a fountain, and a separate reward that's somewhat offbeat but nonetheless mildly useful (in the case of the wine cellar, it's six potions of booze + 3 random potions; other ideas involve stacks of blank paper (perhaps from paper golems); less commonly used tools (perhaps a room containing several musical instruments, some of which are magic?); a stable containing a couple of saddled horses, together with a sack of food for them; and armour of an uncommonly used base type at around +3 enchantment.)
The Minigame Branches
Presently, NetHack has Sokoban, which always branches off one level after the Oracle. In this proposal, Sokoban's location in the dungeon is used for two parallel branches, one of which is a slightly modified Sokoban, and one of which is a new branch named The Arena. Both branches have the same end destination, the Crater Clearing (which is technically part of the Arena in much the same way that the Valley in vanilla is technically part of Gehennom), so a player can attempt either branch depending on how much they like solving Sokoban puzzles. Note that if the Arena is solved, Sokoban can then be completed backwards (which is much easier than completing it forwards) to get at its rewards, giving another option for Sokoban-haters. The branch as a whole is accessed via upwards branch stairs from Dungeons:7 (which connect to Arena:6).
Sokoban is a 4-level branch that acts as a bypass of the Arena, and has a fixed depth, always occupying depths 2, 3, 4, and 5. It's accessed at both ends from the Arena using stairs; Sokoban:5 is accessed from Arena:6, and Sokoban:2 (when completed) provides access to Arena:1.
In these plans, Sokoban has randomly generated levels (because players who like Sokoban prefer them, and players who dislike Sokoban will probably now take the alternative). The level generator creates the levels in such a way that a puzzle needs to be solved, pushing boulders into holes to reach the upstairs. The boulders are given different names and tiles from regular boulders, being more cube-shaped, and thus have two special rules (you can't push them diagonally and you can't squeeze diagonally past them). At the end of each level is a fairly large empty room containing the upstairs; monster generation is biased to drop monsters here most of the time, so the difficulty of combat is based on how long you take to solve the puzzle.
Unlike in the current version of NetHack levels of Sokoban don't have "special physics" nor a penalty for cheating. However, some forms of cheating at the puzzle are prevented using mechanics that already exist from elsewhere in the game:
- The walls are no-dig (but not no-phase);
- The "exit room" is a teleport region (i.e. uncontrolled teleports from outside the region will always land outside it, and the opposite), and an entry region (falling from above will place you there);
- Any uncontrolled levelport in the branch will always move you downwards (in much the same way that uncontrolled levelports elsewhere have limits on how far they can move you downwards);
- There's an extra boulder beyond what would otherwise be the last hole, a hole beyond that, and the entrance to the final room plus a stack of 3 random potions beyond that. The potions are intended as a minor reward for completing the level, but the placement should cause any attempt to force-bolt the boulder to run a chance of destroying the potions too. The boulder's intended to prevent levitation-based solutions; it can't be pushed while levitating, and I'd recommend a change to the game mechanics so that it can't be pickaxed either (using a pickaxe on a boulder while levitating seems really difficult!).
There are, however, two special mechanics. First, it's impossible to take potions of gain level into the branch from outside. This is capable of identifying the potions, and intended to help people understand how the Arena works. It also has a nice side effect of removing an obvious (and highly accessible) method of cheating. Second, pets will not enter the branch, or follow the player within the branch, voluntarily, but will not lose tameness due to separation from the player while the player is in Sokoban (this is mostly just quality of life, as pet management in Sokoban is really boring). As an exception, pets will follow the player into or within the branch if the player has used a whistle recently or the pet is leashed.
In addition to the aforementioned potions, each Sokoban level contains a random ring, and a moderate amount of food (but less than is currently the case; it has too much at the moment); and the first level contains two scrolls of earth halfway through. Sokoban no longer contains random wands (those were moved to the Arena).
The Arena is a 6-level branch occupying depths 1 to 6. Arena:5 to Arena:2 is the Arena proper. Arena:6 consists of a single room containing the stairs from Dungeon:7, the stairs to Sokoban:5, and a cursed potion of gain level; it contains nothing else by default (monsters don't generate in the Arena, and other items don't generate with this level specifically), thus helping to save people from getting far too worried about securing their stashes. Arena:1 is the Crater Clearing, described below.
The Arena has no regular stairs or ladders at all (only branch stairs), and (unlike most branches) does not generate new monsters over time. Movement downwards is accomplished via the use of pre-identified holes (every level has one), meaning the branch is always possible to leave unless you decide to be idiotic and use scrolls of earth or the like; level teleport works (if uncontrolled, it always moves downwards, just like in Sokoban). Movement upwards can only be accomplished using cursed potions of gain level (or controlled level teleport); such potions which generate in the branch have amusing #names in order to encourage people to use them immediately. The aim of each level is, therefore, to kill a monster to get at a cursed potion of gain level in its inventory, allowing access to the next level. (It follows from this that until the player can bring in c!oGL from elsewhere, or gains a controlled level teleport source, they only get one try at the Arena.)
Each level of the Arena is large for a room but small for a dungeon level; a number of different patterns are used (with both open and cramped layouts existing). In addition to the escape hole, it contains a random wand, an item or set of items that provides a nonmagical ranged attack (polearm, camera, bow and arrows, etc.), and a nonintelligent monster or pack of monsters (who won't use the c!oGL or the wand that generates due to being nonintelligent); the c!oGL is in the inventory of one of the monsters. A level can also contain traps, but no trapdoors, holes, or level teleporters will generate other than the escape hole, and the more dangerous kinds of trap will be preidentified. Rewards from clearing the level, besides the items gathered, include the experience you get from the kill, which can be quite sizeable in some cases.
The monster or monsters is drawn from a special encounter table for the Arena, intended to give fights that a character at Arena depth can't win without expending resources. This includes a range of different threats; a player might for example be facing a slow but very powerful enemy at some depths (needing to, e.g., expend ammo ranged-kiting it; I'm assuming melee kiting doesn't work for whatever reason), but be outsped at other depths (perhaps needing to act quickly to lead the attacker into a trap while it's still trying to catch up to the player).
A special level within The Arena, and a "branch end" at that; it's a more flavourful replacement for the Sokoban zoo. Arena:1 is flavourwise a place where a meteor hit the ground above the dungeon, opening up a crater with inaccessibly steep sides (thus it's outside and has a view of the sky, relevant for messages that talk about the ceiling, but doesn't serve as an exit from the dungeon). The level generation is fairly open, consisting of solid rock (which is actually rock, and shows as such in tiles builds) around the outside, and many trees (more commonly around the outside), possibly with small pools dotted around. The level doesn't fill the whole screen, but is nonetheless fairly large (a little larger than one floor of the Wizard of Yendor's Tower).
The level contains a large number of depth-appropriate monsters, and unlike the rest of the Arena, favours intelligent monsters (although basically anything of the right difficulty can generate here). It also likes to generate monsters in groups, even if they don't normally generate in groups. Gold is common here (both on the ground and in monster inventories). There's a guaranteed good item (amulet of reflection, bag of holding, maybe others of similar value?) in the inventory of a random monster, although it isn't distinguished as being anything special (so the player may not be able to identify it immediately). Of course, there are likely to be plenty of other items available via the intelligent monster inventory.
Off to one side of the level is a chaotic altar surrounded by out-of-depth, peaceful intelligent chaotic monsters (of a randomly selected kind, e.g. it might be orcs one game, and elves in a different game). If the altar is converted, they become hostile.
The Crater Clearing contains branch stairs to Sokoban:2, and a pre-identified hole trap that leads to Arena:2. Other level-changing traps (other holes, trapdoors, level teleporters) do not generate, and nor do traps that flavourwise require a ceiling to function.
The Quest is broadly fine as a branch already. Several individual Quest levels (e.g. Rogue-goal, Ranger-start) are problematic and need changing; I'm not particularly planning to go into that level of detail, though.
One thing I explicitly *don't* want to change is the level 14 barrier (which is changed in many variants); one of the main strengths of NetHack's balance is that it gates various areas of the game behind things that you can get elsewhere, and levels is a good example of that. 14 is just high enough that it's possible to get there by grinding in the Valley, or via item (2 potions of gain level is normally enough, as you naturally reach about level 12 going through the Dungeons), meaning that it hits a sweet spot where you can get the Quest unlock with or without items but probably not upon first reaching it. This also means that the quest home level serves as a milestone in its own right (e.g. for getting fire resistance as a valkyrie), but the rest of the quest can be come back to later, thus serving as a separate part of the game.
However, giving an alternative to bypass things like the grind to 14 is still useful. As such, I'd favour giving the Bell of Opening to the quest *leader* (whilst leaving the quest artifact with the quest nemesis); they can be killed for the Bell, giving the resources required to complete the game, regardless of whether the quest is even unlocked. They'll only give up the Bell peacefully if the quest is complete (in the sense of getting the quest artifact), though. This might be useful for speedruns, and is definitely useful in cases that would otherwise be unwinnable. (Quest expulsion would need to be changed or removed; the current cases of expulsion don't function well anyway, with nobody practically failing the alignment test 7 times.)
Formerly an unofficial (and sometimes absent) part of the game, The Maze is now a branch in its own right, and part of the "straight down" path from the dungeon entrance to the Amulet. It consists of three to five filler levels, plus the Castle as a branch end, and is entered from Medusa's Island (via stairs or via digging a hole.)
The top level of the Maze, containing the branch ladder up to the Dungeons, is mostly a filler level but does contain a special room surrounding the ladder itself. The room contains several player-monster statues (with no contents), and serves as a reminder of Medusa's presence for people who are (for whatever reason) approaching her room from below.
Maze filler levels are, of course, mazes (just like Gehennom filler in 3.4.3). Four minotaurs are scattered throughout the filler levels (this means that when the branch is only three levels deep, one of the levels will have two minotaurs); additional minotaurs can also generate here, but only rarely, and this is the only branch where they generate. The monster set for the branch also favours monsters that are naturally capable of digging, phasing, or otherwise cheating at the maze (it seems reasonable that they'd be more likely to enjoy living in one, and also means that the player can be attacked from unexpected directions and that the maze will tend to gain multiple paths over time).
Traps in this branch do not generate on the direct path from stairs to stairs, meaning that they serve indirectly as a clue that the player's going the wrong way. However, items are biased towards generating in dead ends, giving the player more of a reason to explore them anyway. This branch is a good place to put interesting/experimental traps that don't generate elsewhere. One example could be a wall trap, that places a wall on the square the player just came from and then deletes itself (this would replace a wall, and only in cases where two dead ends met end-on, so that the player would not be permanently trapped even after the wall was created). Secret doors should probably be avoided in the branch.
The last level of the Maze is a special level (probably the best-known in NetHack). This consists of a small amount of maze filler at one side, followed by the Castle itself. It's surrounded by a moat (which, unlike Medusa's Island, consists of too many consecutive water squares to make it possible to jump around the Castle, and has a front entrance (via a drawbridge) and a back entrance (which has a fixed land bridge and a regular door); the back entrance isn't accessible without swimming or levitating round the castle, or level teleporting down and climbing back up. All this is the same as before. One notable change is that the branch ladder up from the Valley is now bidirectional; if you get behind the Castle, you can climb down a ladder into the Valley without needing to use a trapdoor.
The Castle's general shape is still the same, although the internal details now vary (e.g. a barracks door might be in a different place, the storerooms in different orientations, or the paths to the corner towers might be connected differently). Instead of being in fixed positions, the trapdoors instead generate guarding "doors that aren't regularly used", i.e. any door in the Castle, other than the entrance door and doors to the barracks, could have a trapdoor generate on one side or the other. The trapdoors can also generate adjacent to the throne. Typically, the level would only have one or two trapdoors. (The idea is to come as a surprise to unspoiled players and occasionally catch out spoiled players too, whilst meaning that trapdoor-luring strategies need a little more thought.)
The Castle's monster set is much the same as before, but most of the monsters (and the liches in particular) start initially asleep, giving the possibility to attempt to do the level via stealth. However, there's quite a chance that the level will wake at some point; the few patrols (a few soldiers scattered inside the Castle) that are awake will be given bugles. Monsters in the courtyard outside, and the sea creatures in the moat, likewise start awake. The barracks doors start unlocked, meaning that the soldiers can leave if they are woken. Note that it may be interesting to vary the monster set from time to time, e.g. introducing other monster categories to replace the soldiers (but still with barracks of their own).
The Castle's rewards are, however, somewhat less useful than before (it's hard to keep them as useful while maintaining any semblance of game balance). The wand of wishing is replaced by a pre-identified magic lamp and an amulet of life saving; still valuable, but nowhere near as much. Additionally, the Castle throne is a special throne that's guaranteed to give a wish, and not vanish, the first time that it's used (and thereafter acts as a normal throne). This gives an expected 1.8 wishes upon reaching the Castle, about ⅓ as much as the previous expected 6 wishes. Note that the storerooms are still present, and there are still four random adult dragons in their general area guarding them; the dragons here are now guaranteed to drop scales, effectively acting as a partial replacement for a dragon scale mail wish.
A very short branch consisting entirely of special levels. This handles the "transition" from the rest of the game into Gehennom, and categorises the levels that partially act as though they were inside Gehennom, and partially act as though they were outside. Notably, prayer and religious actions don't work here (as though the player were in Gehennom), but most other actions work the same way as in the Maze or the Dungeons.
This branch also serves as a barrier to long-distance travel; it is not possible to level or branch teleport within the branch nor past the branch (you can level or branch teleport into it, but will end up very near the entrance in the direction you're going, as if you'd entered via the stairs and staggered a few spaces).
Valley of the Dead
The Valley of the Dead is the first level of the Gateway, and is reached via branch ladder or trapdoor from the Castle (and has a branch ladder back up to near the Castle back entrance). It consists of a large number of graveyards connected by wide corridors, with the accompanying undead monsters. Traps are common, but not particularly dangerous, and often block the path entirely. The far end of the level contains an attended unaligned temple. So far, just the same as before.
The main difference is that the layout is no longer fixed, but rather generated randomly (like most of the other levels), still keeping to a Valley-like level generator. There'd normally be two or three different routes through. The exit stairs, leading to the River of the Dead, are near the temple but not necessarily accessed via the temple itself (they might be in a side route).
The main purpose of this level is to serve as an area to grind experience (for, e.g., the Quest; it's important that it gives enough experience if fully cleared to grind from 12 to 14), and to serve as a clear transition between the first and second halves of the game.
River of the Dead
The River of the Dead is a new level whose purpose is to limit the rate at which trips can be made into and out of Gehennom (and in particular, to prevent the player carting an entire "upper dungeon" stash down to Gehennom with them; that's not only very tedious, it'd also make it almost impossible to maintain the game balance).
The level is dominated by the River itself, which is very wide, and is devoid of items and living enemies (the occasional stray undead enemy would be fine and add a bit of flavour, especially if it was very weak and didn't generate elsewhere, e.g. "raven zombie"). Instead of being made just of water, it's made of something that makes it very dangerous to enter or levitate over, with visible gas coming off it. (IIRC there's something like this in a patch, or possibly Slash'EM; if not, we could design it. At the very least, it should cause major item damage over time, which would be a good reason to avoid going through it.) Because the river strongly discourages crossing it directly, there's a ferryman provided (unique monster, probably @ or &; probably best to use a generic rather than mythological name) who is willing to ferry the player across. (Note that it shouldn't be *impossible* to cross without paying, e.g. in case the player kills the ferryman; it should just that be that the cost typically isn't worth it. Perhaps it's an antimagic gas that drains charges from items and makes noncharged items nonmagical; a bag of holding suddenly becoming a sack could be a real problem.)
Crossing by ferry requires paying a fee. The fee in question is fairly reasonable on the way into Gehennom, but much more expensive on the way out. The exact fee is proportional to total inventory weight (flavourwise because a heavy boat is more dangerous/difficult to row, gameplay-wise so that players are rewarded for thinking about what they need to carry). For a typical player (at this stage of the game, that's probably "with a maxed-out carry capacity, and at the top of Unburdened"), I'd expect the prices to be around 8000zm to enter Gehennom, and 32000zm to leave.
The level contains stairs up to the Valley of the Dead at one side of the river, and branch stairs down to Gehennom at the other end. (The whole "Are you sure you wish to enter?" thing would make more sense being said by the ferryman (or not at all; there's much more clues in the level design now) rather than at the stairs, because it'd be very expensive to turn back at the stairs and because it makes more sense. Even though it does get rid of one of the best-known YAFMCs.)
The Tower of Madness
A "shortcut" branch that once active enables an alternative path from the Maze to Gehennom, without having to obey the restrictions of the Gateway; this is the main reward for solving it, and it's designed to be a reasonable branch to skip entirely. It consists of nine levels, and has a branch entrance on a random Maze level and an exit ten levels deeper, somewhere in Gehennom. It cannot, however, be fully activated without entering it from both sides. Once activated, it's considered as the "main path" through the dungeon as long as you are in, below, or above it; level teleportation to a number within its range will take you to a Madness level, and level and branch teleportation will ignore the Gateway block (because they can conceptually go via Madness levels instead).
Players cannot teleport to a Madness level unless they've already visited it, and all levels closer; this mechanic is partly to avoid people using it as a shortcut out of Gehennom without solving the branch, and partly to avoid characters being trapped on a level with no staircases. Along similar lines, level-changing traps do not generate on the branch, and holes cannot be dug in the floor.
Each Madness level is a fairly small circular level (around the size of Vlad's Tower in vanilla; it might need to be a little bigger). However, upon initially entering it, there is probably nothing in the level but the stairs via which you entered it, making the level appear as an empty circle with nothing but the player and a staircase; while in this mode, no monsters generate on the level. This is because content of each level conceptually only exists while the player has a certain trinsic (or trinsic- or timeout-like property); gaining the trinsic causes a level to be generated around the player on the spot (including a set of stairs to the next level), losing that trinsic causes everything that was generated to permanently vanish.
As an exception, certain actions can cause generated objects, monsters and terrain to become real, and stay even after the level dissipates; a monster will become real if it's tamed or killed, and an item will become real if it's placed in the inventory of the player or of a tame monster, or deathdropped by a dead monster. The stairs to the next level will become real if they're used. If an illusory monster picks up a real item, the item will drop to the ground when the monster disappears. Note that any items that generate here will inherently be infinitely farmable; this is probably a good thing as long as the items themselves aren't too game-breaking, because it makes it possible for the player to look for something specific if they're desperate enough.
Because the level is empty while the player doesn't have the trinsic in question, a "completed" Tower level will therefore have nothing but two staircases and any items that the player has dropped and tame monsters that the player has left behind. As such, a level is trivial to traverse once complete, meaning that the level becomes a shortcut over time (although a complete level will still flare back up into life when the appropriate trinsic is gained). The branch therefore works as a shortcut branch because although it's the same number of levels as the "main dungeon" route, each level is much shorter, and thus the path is much shorter.
The trinsic required for each level is hinted at by an engraving on (or rarely, adjacent to) the stairs, e.g. "Sometimes only the blind can see". Typically speaking, the trinsic would be either negative (e.g, blindness, hallucination), or else rarely used (e.g. monster detection, being polymorphed). It's probably best to avoid things with semi-permanent negative consequences, such as god anger.
The actual level that's generated can vary a lot, and is often in-theme to the chosen trinsic, and/or generated to create ironic situations. For example, a level generated while blind might contain mindless monsters and the occasional chickatrice (forcing the player to remember the location of its corpse). A level that required food poisoning to traverse might be a maze of iron bars (i.e. the entire maze is visible upon generation) with no monsters or items, designed so that the shortest path through the maze would allow the player to take the exit with only one turn left to cure the poisoning. (This may be a bad idea without a clear indication of how long the food poisoning timeout is, but is included as an example of how the themeing works.) A level generated while stunned might just place the exit stairs right next to the player, needing luck to stumble into them before the stunning ends. There probably also shouldn't be a 1-to-1 relationship between trinsics and level themes (although the same trinsic will always create the same level theme on any given game); it'd be fun to have the occasional amusing-but-harmles situation like a player putting on a blindfold and discovering they're surrounded by yellow lights, but only if it's a rare variant that happens as a surprise.
The central (fifth) level of the branch is special, having no relevant trinsic, and an engraving that simply says "Not yet.". The only way to solve this level, therefore, is to approach it from both sides (as the stairs you enter from always become permanently real), connecting the tower into a single continuous tower. The level has a few real items scattered around to serve as a minor reward, but nothing major; my current plan is to place an amulet of lifesaving, plus a few random items.
(A possible variant for the fifth level: with a low probability, make it appear to be a regular Madness level if first approached from above, but make the relevant trinsic levitation. There'd be no way down, and that'd be pretty maddening.)
The basic idea of Gehennom with this redesign is to a) make the main branch less tedious, and b) move depth out of the main branch and into side branches, set up in such a way that typical strategies are likely to jump around between branches (so that the likely monotony of late-game branches becomes less of a problem).
The branch is therefore only 14-18 levels long, considerably shorter than before. Most of the levels are filler levels. The level generator for these levels is substantially changed, generating a number of open areas (larger but not giant towards the top, smaller towards the middle, and starting to open up again at the bottom), and with a network of tunnels around the edges of the areas and connecting them. Many of the tunnels are secret, with all their connections into more open space guarded by secret doors.
Gehennom still has the same special rules as in existing NetHack: religious actions don't work, just like in the Gateway. (Again, like in existing NetHack, this restriction only applies to Gehennom and the Gateway specifically; branches from Gehennom are safe to pray in.)
Gehennom filler levels contain a similar monster set to before. However, I'm hoping that changes to, e.g., the damage formula can make the differences between the monsters that exist there more apparent; if not, the monsters may need to have their stats changed to differentiate them better. Some specific notable changes are that the monsters are changed to be less affected by reflection, magic resistance and magic cancellation (either by changing the monsters or the mechanics); and that elemental attacks typically partially bypass intrinsic resistances (with extrinisic resistances still blocking them).
The basic aim here is to prevent the player being able to tank most of the incoming attacks using items they already have, needing to explore Gehennom and the surrounding branches to help gain relevant equipment. As such, the quality of items that generate here is better than it would be in the pre-Castle branches, and rare items are more common. It may be necessary to add a number of extra items to the game in order to give Gehennom a selection of items of its own. The Gehennom main branch favours generating gold, gems, and consumables, although nonconsumable equipment generates too at a rarer rate.
Filler levels can, of course, also contain traps. This isn't very effective in the current versions of NetHack, serving mostly to block pathing, because traps don't really scale as the game goes on. In the new version of Gehennom, the traps will have to be rather nastier to be relevant; unlike traps in the Maze, which can be quite complex and interesting and mini-puzzles by themselves, traps in Gehennom are more of a straightforward depth-resistance thing (i.e. designed to force unprepared characters to waste resources or retreat).
Unlike previously, bosses (both the existing bosses of Gehennom special levels (other than the Wizard of Yendor), and newly designed bosses that don't necessarily have to be similar to the existing ones) can appear randomly on filler levels rather than necessarily needing their own lair or to be summoned by a lesser demon. (The current lairs are not really a good fit for the game anyway; apart from the ruined town, they don't play significantly differently from filler levels, but are rather more tedious to walk through after they're already complete.) These are, if necessary, redesigned to ensure that they present a notably different challenge from other monsters; for example, they could have unusual defences (e.g. immunity to most forms of attack), or use unusual forms of attack that force characters who don't have appropriate counters to them to escape via running away or using escape items.
The above is a special case of something more general: Gehennom should have something of the "depth/resistance" balance property used by many roguelikes, becoming much more dangerous at specific depths if the player is lacking in certain relevant items (be they extrinsics, consumables, or something else). This ties into the theme of giving the player incentives to explore rather than diving, and also into the theme of encouraging players to take breaks to enter side branches. (That said, when nearer the bottom of the dungeon, diving may well be a better strategy than facing the presumably nightmarishly difficult monsters that exist.)
Amongst the filler levels are a few branch entrances, but also a few special levels. The special levels are intended to give the player a chance to restock, regroup, make stashes, etc., and thus are notably easier in terms of than the surrounding filler levels, at least once cleared. (NetHack levels typically can't be cleared – they start with very few monsters and most of the encountered monsters are generated over time – but special levels start with their own stock of monsters and thus are easier once cleared than they are to begin with, despite the fact that monsters continue to generate after clearing them.) The shallowest of these "restock levels" is the Black Market, explained in much more detail below (although it can't be used to make a stash, the entrance to the Tower of Madness has a similar depth, and serves as a good stash location in its own right).
There are two other such levels, one approximately halfway and one three-quarters of the way through Gehennom, and each drawn from a rotation of special levels appropriate for restocking. Typical features of these levels include terrain beneficial to the player (sinks, fountains, unaligned altars, etc.), storerooms containing specific consumables (possibly guarded), and safe areas which can be easily secured against arriving monsters. Note that the level can be harder from the point of view of traversing it, even if there's less risk from the monsters in the area; for example, being disconnected or requiring levitation are both reasonable.
There are a couple of existing Gehennom special levels (the swamp and the ruined town) that can reasonably be adapted into restock levels. However, a larger selection is likely to be beneficial.
The Black Market
The Black Market (inspired by the Slash'EM branch) is the first special level in Gehennom, appearing 1 or 2 levels below the level containing the branch to the Tower of Madness (thus ensuring that the Black Market is always on the ascension run route, whichever way you take it). It's basically a shop that covers an entire level, with a very large stock of items (although unlike typical shops, not every square starts with an item). Buy prices here are much, much higher than in most shops; sell prices are possibly a little higher, but not by much. However, the shopkeeper (One-Eyed Sam) has effectively unlimited gold to buy things from the character (this means that identified gems can be converted into gold here, making it possible to use them to purchase other items or to pay the ferryman), but will buy only score-bearing items (i.e. gems, artifacts, and invocation items; selling invocation items during the ascension run might even be a potentially viable tactic to get enough gold for an emergency purchase). The basic idea here is to give gold a use late-game, and to effectively replace some of the wishes that are missing from the Castle via letting the player buy a few items to help round out their ascension kit, or alterntiavely buy any consumables that they might happen to badly need; buying only score-bearing items removes any incentive to collect and sell the entire contents of the dungeon (an incentive that's removed for other shopkeepers by their limited gold holdings).
Of course, with a level-sized shop, there would be notable problems if the player could steal the whole thing. As such, there are several protections against this. Credit cloning is impossible because the shop spans the whole level, and thus has no "outside"; pets will not be able to take unpaid items up or down the stairs, or through a level teleport (they'll drop them before changing level). The floor is too hard to dig in. While the character owes the shopkeeper, they'll be unable to use any form of teleportation, and the stairs will be blocked off by "enforcer" monsters that are allied to One-Eyed Sam (basically, an ogre-type monster with out-of-depth stats); these treat the stairs much like regular shopkeepers treat their shop doorway, blocking the stairs as long as the player has unpaid items.
Another notable protection is that the shop does not allow customers to have too many unpaid items at once. Trying to pick up more than a few stacks of items will give a warning at first, and then turn the level hostile.
One-Eyed Sam him/herself has boss-level stats, and is capable of following the player anywhere but Astral and respawning if killed (much the same way as the Wizard of Yendor); once angered, the only way to prevent him/her harrassing the thief indefinitely (and regain the ability to teleport!) is to pay any debt incurred (a scroll of taming does not work in this case); debt and unpaid items from the Black Market are tracked forever, even in cases where a theft would otherwise be counted as "successful" by the game and clear the unpaid flag. He/she notably has an attack that turns the floor beneath and around the player (in, perhaps, a lantern radius shape) into lava, destroying or damaging any items there (and making them very hard to pick up as a side effect); this makes it almost impossible to loot the level with an angry Sam (especially as if you levitate to avoid the lava, you can't pick up items).
To avoid potential problems with bones files, the Black Market is not bones-eligible, and One-Eyed Sam will not appear in bones files either.
The Vibrating Square Level
The penultimate level of Gehennom. The level is laid out using the filler level generation algorithm, but has a few notable differences. First, there's a drop in the difficulty of the monsters (placing the difficulty at about that of mid-Gehennom), and no bosses. Second, the level is unnaturally dark; no square on the level is naturally lit (although that's nothing special for Gehennom), nonmagical light sources fail to function entirely, and magical light sources are interfered with (scrolls and wands of light have a reduced radius, as do magic lamps and the Candelabrum; the spell of light is more expensive in Pw than normal and also reduces maxPw when cast here), although light emitted by monsters still functions as normal (mostly to allow an alternative method of solving the level). Most notably, though, the level has no downstairs, and it's impossible to travel below here by any means until the downstairs are created.
The aim of the level is to find the "vibrating square". This is a square chosen at random (that's in a room, not a corridor, and isn't near an edge of the level). It cannot be found until it the vibrating square is lit, at which point an identified "vibrating square" trap (which does nothing) is placed on the square as a method of marking the location. It's then possible to do the Invocation on the square (light Candelabrum, ring Bell, read Book) in order to change it into the downstairs that leads to the Sanctum.
The deepest (but not last!) level of the game. This already functions pretty well (once the "amulet delivery service" glitch was fixed; the other tricks used on this level, such as "level teleport in, cursed potion of gain level out" are interesting and not broken and thus can probably safely be left in). The main problem that the level is suffering from is having a fixed layout, which causes some parts of the level to be irrelevant once you've memorized it. As such, this level could do with having more variants that aren't immediately distinguishable, or (ideally) a random generator of its own. The level basically consists of a few rooms, the last of which contains an interior room that's an unaligned temple, surrounded by fire traps and accessed by a secret door. Some of the rooms contain just a few priests (including the entrance, and the courtyard surrounding the temple, but possibly others too); at least one room that has to be passed through on the way is packed with demons and undead.
The High Priest here actually works pretty well as a boss (basically just based on the very large melee damage he or she deals; the standard priest behaviour is less interesting). As usual, he/she has the genuine Amulet of Yendor, which is the main reason to come here. I'd recommend giving the High Priest a guaranteed cloak of magic resistance (death-raying bosses is an interesting tradeoff when they respawn, but not really when they don't; note that other instakills still work here), and otherwise leaving the boss fight unchanged.
Gehennom during the ascension run
After the Amulet is obtained, a few changes are made to Gehennom. The mysterious force no longer drags players back downwards, but several changes are needed to compensate for this. There are two categories of negative effects that affect the player during the ascension run; both of these are periodic effects that take place on a turncount timer (meaning that the faster you move through Gehennom, the less you're affected). This serves both as a method of rewarding players who choose to spend time terraforming Gehennom (giving another way in which players can prepare; many players seem to like this sort of playstyle), and as a method of positive feedback (if you get in trouble, you're likely to get into more trouble); positive feedback is desirable late in permadeath games as it gives a method of increasing the amount of risk/tension involved and makes management of escape items (which the player will have a lot of by that point) more important.
The first category of effects are "collapsing Gehennom" effects; removing the Amulet from its previous location causes the place to become less stable. This manifests in occasional shifts in terrain, typically ones which block the most direct path to the stairs (calculated via pathfinding or perhaps simply crow-flies direction; a particularly insane player can use this as a method to help locate the upstairs if they've never visited the level before). These effects involve both wall/floor collapses (similar to a localised drum of earthquake effect), and ceiling collapses (creation of a large number of boulders, and monsters falling down along with and among them; the effects can happen separately or together. The basic aim here is to prevent the player simply walking along a pre-prepared escape route on every level, whilst giving a flavourful way to add more difficult combat situations.
Note that collapsing Gehennom effects can and probably sometimes should generate miniboss-level monsters that weren't previously in the dungeon. Ideally, these would *not* covetous teleportation (so that it's possible to simply outrun them if you take a wide berth around the location of the collapse).
The second category of effects are more direct interference with the player; unlike collapsing Gehennom effects, which are basically just the branch losing a mild amount of structural integrity, this is flavoured more like the Wizard of Yendor or some similar force actively trying to stop the player. It's a generalisation of the `intervene` system used by the Wizard of Yendor in 3.4.3. One notable change is that it happens considerably more frequently than it used to (as a consequence of the Mysterious Force being removed, ascension runs are shorter, so interventions have to happen more frequently than they used to); in order to avoid hurting unspoiled players who do Gehennom out of the optimal order, this increase in frequency only applies once the Amulet is first collected. (Or perhaps only while the Amulet is in inventory? It'd be interesting to trigger an effect as long as it had been X turns since the previous effect and the Amulet is in inventory, especially as it means that dropping the Amulet and later picking it up might well instantly trigger an effect, which seems very flavourful).
In addition to the increase in intervention frequency, there's also more variety in the intervention effects. One effect that the game needs in some volume (although less than 3.4.3!) is something that causes the player to go through a level on the ascension run more than once (giving more of an incentive to connect the stairs). Probably the best way to do this is to just swap the main staircases on the level with a probability that increases the nearer the player is to the upstairs (ideally with a message that's also used for something else, so that the player can't just automatically backtrack); this also has the advantage that it discourages just waiting at the upstairs for a Gehennom collapse event to occur, a strategy which could otherwise make collapses mostly irrelevant. There's plenty of scope for other interesting actions, though (e.g. unequipping some of the player's items, random negative status effects, teleporting the player but not the Amulet); basically anything that could cause a player to rethink their plans either strategically or tactically. (Semipermanent effects need some care here, as they could make slower ascension strategies unviable; things that can be dealt with using consumables, like Rodney reappearance (semipermanent as he's stronger each time) and item cursing, are probably OK, but it's best not to expand the list too much.)
Unrelated to the above, monsters spawn faster during the ascension run, spawn when a level is first re-entered in addition to while the player is on the level, and are more likely to spawn at or near the upstairs; this is mostly an attempt to prevent controlled teleport shortcutting past the whole thing (as there's a decent chance you'll try to teleport onto a monster).
Finally, there are a few positives during the ascension run, too; not everybody hates you, after all. If One-Eyed Sam is still alive and has a good opinion of the player (probably defined as "has never been angered and has made at least one transaction"), he or she defends the player (by attacking the player's attackers, taking care to avoid collateral damage to the player) as they go through the Black Market. (It should be pretty fun seeing enemies falling into summoned lava!) Of course, there are obvious ways this can go wrong (if the enemy had the Amulet at the time, you're going to have to dig it up and then buy it back), and should you happen to be on the ascension run with an angry Black Market, you're going to have to go through it on the way up, which is likely not present at all.
The collapsing-Gehennom effects cease once the player is outside Gehennom. The interventions continue all game, but become less common/dangerous once in the upper Dungeons and in the Planes (basically because the player has other things to deal with in the Planes, and interventions in the Dungeons are unlikely to kill or really affect the player and so too many would just get tedious). This also makes it reasonable for the player to make one last trip to their "upper dungeon stash", which (if they didn't complete the Tower of Madness) they may not have visited in a very long time, and for unspoiled players to talk to their Quest leader due to taking the instruction "get the Amulet of Yendor" too literally.
Eternity is a branch accessed by branch downstairs on a shallow Gehennom level (level 2-6 from the start of Gehennom, but not the same level as the Black Market, nor as the entrance to the Tower of Madness), consisting of 8-10 levels. The design is similar to that of room-and-corridor levels, except that the corridors are a bit wider (thus effectively being long, thin, and possibly diagonal rooms of their own); the current plan for the level generator is to generate a room-and-corridor level, then make every square orthogonally adjacent to a corridor into a room tile of its own. This is the "Mines of Gehennom", a branch that's accessible early, and intended to be interspersed with the main branch (i.e. it'd be unusual to do the whole thing in one go).
The major gimmick of this area is that, although it's possible for players and monsters to move around, time doesn't pass. The only things that happen at turn boundaries are the refilling of movement points on players and monsters, (to avoid an obvious unfair instadeath) helplessness timing out, and (for gameplay reasons) monsters spawning. This notably means that HP and Pw don't regenerate inside the branch, timers don't run, and short-term spell and potion effects can be kept around indefinitely (but negative status will be too). To give a strong clue as to what's going on, the turn counter doesn't increase inside the branch either (and should probably change colour). Ideally, time wouldn't pass inside the branch even while the player was outside the branch, but that might be fairly hard to program.
The aim of the gimmick is to cause a shift in gameplay priorities inside the branch; unlike the mostly tactical Gehennom, where the effects of combat disappear quickly, they're semipermanent in this branch (lasting until you leave it). Leaving the branch is also a simple way to make time pass again and cure your issues, encouraging multiple dips into the branch rather than doing it all at once. Note that this means that monsters need to be rather easier on average here than they are in Gehennom; we're aiming for a "death by a thousand cuts" type of scenario. Additionally, spellcasting monsters (and any monster that relies on `mspec_used`) do not generate here, because they would only be able to cast one spell ever (thus flavourwise they wouldn't like being in the branch, and gameplaywise they'd be disproportionately easy to beat).
Special terrain features do not generate here. Visually, the area should have a very "clean" look, partly because that seems reasonable for an area where time doesn't pass, partly to make a contrast to the piles of corpses and deathdropped items marking where monsters died.
Because this branch is not part of Gehennom, prayer is possible here. While in the branch, being at less than full HP or Pw are considered minor troubles (in addition to the existing consideration of, e.g., blindness as a minor trouble). This means that prayer can be used as a method of fixing the lack of regeneration.
The branch's item set tends towards nonconsumable items (this is partly because nonconsumable items are more useful in Gehennom than here, and the consumables that generate in Gehennom are more useful here than there, and partly for flavour reasons). Gold and normal gems don't generate here (they seem out of theme, and are common in Gehennom, so this helps to make a contrast). It's also reasonable for corpses to generate here; that wouldn't make sense in any other branch, but is very reasonable here (especially as corpses will, unless eaten, remain indefinitely, and nobody needs to eat while they're here unless they're casting hungering spells or the like).
There's also an item that generates only in this branch, and is one of the main reasons for coming here: time essence. This is a magical type of gem; in addition to being valuable (thus being usable for score at the end of the game, or saleable to buy things in the Black Market), it can be applied in order to "freeze time" for a moment (thus being very valuable in the late game). This allows the player to take several actions in the same turn, without monsters being able to respond. Time essence rarely generates with filler levels, just lying on the ground.
Although it consists mostly of filler levels, there are also a couple of special levels in this branch:
The Golem Shrine
This is approximately halfway through Eternity, and rather more open than most levels in the branch; it's likely to be a handcrafted special level with a fairly regular structure (possibly with a few variants). Golems are very common here, and may generate peaceful even if they normally wouldn't. (Other monsters can also generate, but in lower quantities.)
Unlike most of the levels in the branch, where consumables are rare, there are guaranteed to be some consumables helpful in the branch here (e.g. status-curing and healing potions). As such, this serves as a useful "pit stop", at least the first time. Magic traps are also common here, and have Pw restoration as a fairly common additional effect (which the golems with breath weapons can use to recharge their ability to breathe).
The level has a guaranteed lawful altar (although there's nothing preventing characters of other alignments simply converting it). The altar is not attended by a priest, but is in a fairly securable area. Because being below full HP is a minor trouble in this branch, it should be possible to heal up via carting corpses to the altar (from this level and elsewhere; note that they don't decay in this branch, so will be sacrificable forever) and using them to regain prayer timeout. (Possible enhancement: the act of sacrificing itself gives you partial HP and Pw recharges, proportional to the value of the sacrificed monster.)
Chamber of Desire
This is the last level of Eternity. It's a medium-sized octagonal room, and the scene of a boss fight. The decor / flavour is themed around reflectivity (e.g. mirrors are fairly likely to generate here).
The boss is the Infinite Dragon, who's similar to a silver dragon (but a separate monster, much like Ixoth is similar to a red dragon but a separate monster). It has much higher HP and accuracy than a typical silver dragon, and its breath has much higher range (and it can bounce it off walls, meaning that some thought is needed to stay out of range of the breath weapon). It also summons monsters over time (perhaps a new sort of monster designed for the fight). Unlike everything else in the branch, its HP and special attacks regenerate normally over time (meaning that it can't be worn down over the course of multiple trips).
The Infinite Dragon's scales (which are always dropped) give reflection and immunity to haste, slow and paralysis; while wearing them, you always get exactly 1 action per turn, except in cases where occupations are faked using helplessness. If worn inside Eternity, the player takes actions at the same rate a speed 12 monster would, and although the turn counter remains frozen, the player's HP and Pw regenerate like they normally would rather than remaining constant (likewise, any status effects that would typically time out do so). Infinite dragon scales (by themselves or as an armour) are thus meant to be a niche/side option that most players will avoid (as speed is a property that most players want to be able to use),
The main reason players will come here, though, is for the wand of wishing (which is in the Infinite Dragon's initial inventory). This always contains exactly three wishes (which with vanilla wand of wishing mechanics, would make it generate at (1:2) charge). The basic idea here is to move some of the Castle wishes to later in the game (as Eternity is intended to be done in parallel with Gehennom), whilst giving a major reason to actually attempt the branch (although it plays differently from Gehennom, it doesn't have a major genre shift or anything that changes the fundamentals of the game).
The Tower of Silence
Vlad's Tower, except Vlad isn't here any more.
This branch has an upwards entrance somewhere deep in Gehennom (in the bottom third). The main gimmick of the branch is that magic doesn't function here; specifically, all items act as though they were cancelled (without actually cancelling the item; it goes back to normal upon leaving the branch), magical items that are normally unaffected by cancellation (e.g. amulets) cease to have any properties, and the player's current Pw is locked at 0 (with all monsters acting as though they were cancelled too). It's probably best for this to show up on the interface too in some way or another; either showing the cancelled stats of items, or else abstracting away their properties (perhaps by giving !dknown descriptions, because the material an item's made of is more relevant than the item itself over here). Note that a side effect of this is that entering this branch can be used as a simple way to unequip cursed equipment, which is probably a good thing (as it makes two-handed weapons less dangerous at the point of the game where they're most likely to get randomly cursed).
The branch is made entirely of filler levels, which are the same size as Vlad's Tower levels (i.e. pretty small) but more open (perhaps damaged versions of the old Vlad's Tower maps with walls removed?), and with frequent pre-identified trapdoors (Vlad *was* here, after all; this also serves as an escape item equivalent as most actual escape items don't function here, and serves to add some tactics to the branch because strategy isn't very relevant here). The enemy selection consists of a mix of humanoid-ish monsters with weapons (often not particularly good ones), slow-moving monsters that hit hard, and enemies which are resistant to certain weapon types (as weapon selection is much more important here than elsewhere). Flavourwise, this should basically be seen as "a bunch of demons and undead and their pets". Items here tend towards those which are useful when nonmagical (weapons and armour), and are more commonly cursed or negatively enchanted than elsewhere (as it wouldn't matter to the people who live here). As a result, this branch is very much somewhere you go through to get to the end, rather than somewhere you spend time grinding. Additionally, the monster generation rate is high, but typically only while you *aren't* on a level (i.e. if you kill monsters and leave the level, they come back).
The top level of the branch (which is short, probably 3 or 4 levels) is still laid out as a filler level, but instead of random enemies, contains what's basically a unique long worm as the boss (that starts out "pre-lengthened" to a fairly long length). It can only attack using its head (meaning that careful placement is important), has attack power proportional to its length (meaning that cutting it in half can be a viable strategy), and has speed chosen so that an intrinsically-fast player moves faster than it on average but it will double-turn such a player sometimes (this implies a speed of around 15). It drops a selection of gold objects when killed, including the Candelabrum of Invocation (which it presumably gathered because it just likes gold).
The surface, internally "level 0" (but perhaps not for UI purposes), is basically a tutorial level. The game starts here, with the player having only a minimal subset of their starting inventory, and with a level designed specifically for the player character's class, to teach them the relevant basics of gameplay for that class in particular. The level is entirely scripted, and only takes up about 2/3 of the screen vertically (in order to allow the rest of the screen to be an extended message area giving explanations on what to do both in terms of in-game actions and in terms of the commands used to achieve them). Ideally this is done in a flavoured way, with quest friendlies giving advice; however, it's situated at an "above the Dungeons" location, not at the Quest home location.
After teaching the player the basics of how their character works, they can enter the dungeon at Dungeons:1 via a set of downstairs. However, the `>` command here is special, and just ends the tutorial and places the character into the Dungeon with their standard starting inventory, fully healed, etc., regardless of what happened in the tutorial (and even whether they reached the downstairs or not); this both means that playing the tutorial can't get you an advantage, and that the tutorial can be skipped by players who already know how to play. (A "press `>` to skip the tutorial" message is permanently onscreen while the tutorial is ongoing.) The tutorial always appears, but skipping it is likely to end up part of an experienced player's muscle-memory.
Of course, NetHack players being what they are, there are likely to be attempts to sequence-break the tutorial. Attempts that make the game impossible to complete should likely lead to amusing (and unique!) death messages. In particular, it should be possible to run off the map and never go into the dungeon at all, with a corresponding epitaph.
The surface also makes a couple of cameos later in the game. Most notably, after escaping the Dungeon, the quest friendlies (who have been camping round the entrance) comment on the escape before the game ends. This serves partly as flavour, and partly to help explain to new players what an escape actually means. They also (for TDTTOE reasons) comment on the result of a level teleport into the closer negatives. (Note that it's possible that a lifesaved teleport into the -1 to -9 range could be made survivable, rather than being an automatic escape, now that a separate surface level exists; the player could be given the option of leaving or going back inside.)
Finally, upon leaving the Dungeon with the Amulet, a portal (leading to the Planes) appears on the surface level. I'm unsure whether the player should enter it automatically, or whether they should have the choice to *not* ascend and just escape with the Amulet; in the latter case, there should at least be some resistance from the quest friendlies (to not offering the Amulet to the appropriate deity if the player is of the original alignment, or against the player if they've converted; HoOA may be a special case here). At any rate, the character should feel a strong urge / attraction to move towards the portal, flavourwise, as the relevant deities are rather likely to want it on Astral.
The Elemental Planes
The Elemental Planes is the first "postgame" branch, accessed from the surface when the player has the Amulet of Yendor. This is a branch consisting of four special levels (nominally not part of the normal numbering system, although they're likely called -1 to -4 in things like xlogfile reports). Just like before, the branches have no stairs or portal back, and the aim on each level is to reach a portal to the next level. As such, the Planes are essentially movement puzzles with some amount of combat involved. The Plane of Earth is always first; the other three appear in random order. (Placing Earth first makes it possible to use the entry chamber for a setpiece that wouldn't function on other planes.)
Each of the Planes can be magic-mapped (allowing players to determine their layout even though all the layouts are now randomized), and the portals can be detected via standard portal detection means.
Plane of Earth
The Plane of Earth is always the first elemental plane. The starting area is a small and compact chamber containing the Wizard of Yendor (who drops a spellbook of dig on death), an Elvenking (who drops a pickaxe on death), and a random player-monster (whose death drops a cheap plastic imitation of an Amulet of Yendor, a blessed potion of monster detection, an uncursed scroll of magic mapping, and a cursed scroll of gold detection). The basic idea here is to provide a fight that can't reasonably be run from, and some basic resources for the Planes (the player might or might not be carrying more useful portal detection with them). Notably, there's no guaranteed wand of dig here; those things are fairly plentiful as it is, and the player will have very little future use for them, so adding an extra one doesn't really make sense.
The level itself, apart from the starting chamber, consists mostly of a scattering of medium-sized open spaces (maybe about 20 squares in area) that do not have compact shapes (i.e. they never get very wide), surrounded by diggable rock and the occasional undiggable obstacle (which could be iron bars or could be some sort of rock created for the occasion; it'd have to look different to regular rock when magic-mapped). The portal to the next Plane is somewhere in the opposite quarter of the map from where the player starts (this is a change from previously). The level does not naturally generate items useful in combat (although gems are scattered all over the level (typically fairly low-valued ones), rocks are very common, and gold generates in a smaller amount, with boulders existing but rarer still), and open spaces other than the one where the player enters can contain the occasional rare pit trap (flavoured as being naturally generated) or rock trap (ditto, the rocks don't come from a trapdoor but from the unstable earth above). In general, this has the feeling of a naturally generated area, rather than manmade like the Dungeons are.
Digging works differently from before; instead of pickaxes digging a cavern and creating monsters (which is fairly tedious and such a bad option compared to the others that few playesr ever do it), pickaxes can dig through diggable walls here in a single turn (i.e. 1 action + the rest of the turn). Meanwhile, wands and spells of digging have a limited range here, digging only 2-3 squares in the direction zapped (helping to ensure that the level can't be done using a single wand and that the player can't move too fast).
Aside from the initial battle, the challenge here consists of a number of monsters who make this plane their home. The "popcorn" enemies, that are mostly there for flavour, include several xorns (scattered around the level), and in the chambers other than the starting chambers, some additional metal- and rock-themed monsters (iron golems, rock and iron piercers, and rock trolls; not rock moles, though, because they'd eat the chambers larger before the player got there).
The main challenge, though, comes from earth elementals, which are *very* powerful on this Plane (with hundreds of hitpoints, enough accuracy to consistently hit an endgame player, and dealing around 120 base damage on hit; they're also sped up to speed 12). The idea is that the player will benefit from outrunning/dodging them, rather than fighting them (although items like wands of death will work in emergencies); the potion of detect monsters can be used to track their location (at least for a while), and the player is probably hasted and thus able to outrun them on open ground (but they have the speed advantage if the player has to dig). Hopefully, the goal of figuring out how to avoid earth elementals is an interesting one. The density is large enough that they'll inevitably encounter the player en route to the portal, but they start far enough away from the starting chamber that they're unlikely to interfere with the initial battle.
Plane of Air
The Plane of Air works very well already and hardly needs changing. The only change I'd make from 3.4.3 would be to the cloud layout, making it random rather than predetermined; the map generator should always generate an obvious thin point in the clouds that's only three squares wide ("obvious" in that you can tell where it is just by looking at the clouds from the start of the level), and a cloud-free route through that's rather indirect or maze-like. (I'd also ensure that the level is lit, for both flavour and gameplay reasons, but IIRC it is already; if not, though, I'd want to change that.)
Plane of Fire
The Plane of Fire is noticeably changed in gameplay (the 3.4.3 version is fairly tedious, especially with respect to messages). The core layout of the plane (floor and lava, with many fire-immune and fire-using enemies) is still the same, as it's a good "base" for the level, but many other things change.
There are some minor changes to do with flavour. Squares are unlit unless over or adjacent to lava, in which case they're lit. (IIRC many fiery monsters illuminate the area around them too; that's even more flavourful.) Fire elementals here move faster (speed 24) and hit harder (dealing some damage even through fire resistance), but are nonetheless not expected to be a significant threat; additionally, every hit burns (or worsens the burn on) two non-fireproof items in main inventory which have an appropriate material, even if they wouldn't normally burn (e.g. sacks); this is just flavour as most such items that wouldn't "naturally" burn in this situation have no erosion effects defined anyway.
There are also some notable changes to deal with message spam. Fire traps are removed from the level, as they cause way too much trouble with fire-resistant monsters and the player is probably not inconvenienced by them anyway (this also means that the cursed scroll of gold detection can be used on Fire if the player wants to); they also aren't great flavourwise because it's unclear why pillars of flame would be touch-triggered. Additionally, the monsters here (and especially fire elementals) are highly resistant to or immune to conflict (again to cut down on messages; they mostly can't hurt each other anyway).
On to the actual gameplay of the plane. The character starts very near (6-7 squares from) one edge of the plane (probably the east, for consistency with vanilla); the portal is equally near to the other edge. "Behind" the character (i.e. nearer the near edge, further from the portal) is an advancing inferno that covers the entire height of the level, is initially two squares wide, and gradually (on any given turn, each inferno square has a 2 in 3 chance of making an orthogonally adjacent square that isn't currently an inferno into an inferno). Once a square becomes inferno, it never turns back. Inferno is effectively on the "regions" layer of the map (like stinking clouds are), so can exist "above" a floor, lava, or portal tile. Whenever inferno expands onto the character's tile or the character takes a time-consuming action that leaves them on an inferno tile, they die (if not fire-resistant) or take heavy damage (if fire-resistant), likely on the order of 60 damage or so (that isn't resisted by half damage because it's neither physical nor a spell). As such, this level is pretty much a race to reach the portal before the inferno does; dawdling here is likely to end the game fairly quickly.
In order to slow down the player's sprint to the portal, the enemies of the plane (most of which are irrelevant damage-wise) are evenly distributed across the level and moderately dense; being able to kill them quickly is advisable. (They should probably have HP in the range that allows them to die to 1-2 blasts of a wand of cold, likely the most effective area attack against them available to non-spellcasters.)
Plane of Water
The existing Plane of Water is very tedious to do by moving around within the bubbles; in 3.4.3 you can just go over the bubbles, in 3.6.0 you can't, and people rarely go between the bubbles. However, underwater combat is the obvious thing to do with this Plane, and so this design focuses on it.
The level still consists of bubbles surrounded by water, and (like 3.6.0) the bubbles are conceptually three-dimensional (with water "above" them) so the water can't be levitated over. However, there are considerably fewer bubbles (only 4 or 5, each around as large as the largest bubbles in vanilla NetHack); the starting bubble is isolated at one end of the level, with the other bubbles scattered over the far side. One of them contains the portal.
The starting bubble contains a guaranteed water nymph who deathdrops an amulet of magical breathing in an oilskin sack (the basic equipment required to get through the level, and a strong clue as to what you're meant to do). Apart from that, the monsters are much the same as before. Again, water elementals are made stronger here for flavour reasons, this time raising them to stats that will give a notable challenge to the player (especially as many of their standard tactics may not work underwater!), whilst not being worthy of a boss. Other monsters capable of swimming are here too, but probably won't give too much trouble; note that most healing sources don't work well underwater (even the amulet of life saving doesn't work as you can't take off the amulet of magical breathing to put it on), so care will be needed in balancing combat here as escape options are very limited compared to normal.
The Astral Plane is, for most characters, the final test that determines who will win and who will lose. The general idea, of forcing the player to fight their way to an altar and then back out to check the next one, is a good one. It would be great if the player could somehow be forced to always check multiple altars, but it's hard to think of a non-arbitrary way to do this; the arbitrary way, and the way I'd go for if no better option presents itself, is to cheat via only selecting the identity of an altar once the player has enough information to deduce what it is.
The general enemy makeup here is fairly good already, posing a real challenge to players who have only moderate preparation. Unfortunately, very highly prepared players can sometimes just breeze through tanking everything, which is a problem. Making the player stats too irrelevant would *also* be a problem, though, so the best compromise is probably to ensure that all three Riders have an attack that "levels" max HP (via taking off max HP, more so if it's already high). Death already has an attack like this; in this proposal, the other Riders' attacks also have the max-HP-reduction effect that Death gets, and Death's attack gets a level-drain side effect to compensate (incidentally, it makes sense if Death has the weakest special attack, being the hardest Rider to kill). None of these attacks can be blocked by magic cancellation, of course.
The situation with conflict also needs some changes; it should ideally be an option rather than something that's clearly the best. One change it needs is a general improvement to conflict resistance among all monsters on the level (not immunity, just enough that it's noticeably less effective). Another change, which would make the plane more friendly to unspoiled players, is to summon several (most likely 4) guardian angels upon arrival, and make them so that instead of disappearing when conflicted (and sending in weaker replacements), they always attack the player's character while conflicted (whilst remaining tame) but go back to normal if conflict is removed. The player will therefore have the option of killing them (with likely penalties) or somehow ditching them in order to keep conflict, or else removing conflict to keep them on their side; and wearing conflict onto the plane by mistake won't force the player into a decision early. If the player's alignment record is poor, the same number of angels still appear, but fewer are tame (some will be angels of other gods and thus hostile), with only one tame (and three hostile) angels at 0 or negative alignment (one for each relevant deity).
Apart from that, few changes are made to Astral in the common case; it mostly functions very well, so not much needs changing. However, there are some rarer cases, to do with conducts; see the sections below.
Upon offering the genuine Amulet, the player is taken to one final level, simply called "Endgame". Assuming the player ascended correctly, this is an unloseable level whose purpose is to make for a more satisfying ending to the game than a few lines of text. As such, the player's stats at ascension (for, e.g., the dumplog and for scoring purposes) are recorded prior to Endgame.
While in Endgame under ascension conditions, the player is conceptually already an immortal demigod. This is represented game-mechanically by ensuring that nothing bad can happen to the character; most notably, damage increases the character's maxHP rather than reducing the character's current HP (so the "amount of damage the character has taken" increases by the expected amount upon taking damage, but there's no way to die to damage). Status conditions, lost abilities, etc., automatically heal themselves in a few turns; instadeaths reverse themselves instantly; eroded items repair themselves; and in general the feeling of invincibility should be quite clear.
Prayer (and other religious actions) do not function here; the game refuses to acknowledge the command. The interventions caused by killing the Wizard of Yendor no longer occur either (they'd be very out of place, and also the Amulet has now been permanently rehomed so he has no reason to interfere any more).
The level itself is mostly a featureless void which has a very high monster generation rate (which gets higher the fewer monsters are remaining, and which is willing to generate monsters in view of the player). Every now and then, something from the character's history will appear nearby for a few turns and then disappear again; perhaps a door with a wall on it, the room containing the player's stash, or some other notable area. The monsters themselves are likewise from the character's history, being taken from the character's kill records (i.e. if the character killed 4 newts, up to 4 newts can appear here). The monsters appear in roughly depth order, with the effective depth from which the monsters generate increasing over time (mostly independently of how many monsters the player kills, although it speeds up if there are no more monsters of an appropriate depth to generate); when the effective depth catches up to Astral, a (pre-identified) portal appears over the other end of the level from the player's current location, and taking the portal ends the game. Note that not every monster the character has killed will necessarily generate here; killing the entire dungeon all over again would be far too tedious. This is basically just a sample that should be reminiscent of what the player's done so far.
One very unusual feature of the level is the message area. It doesn't show gameplay-related messages at all (they're kind of irrelevant in the victory lap). Instead, it gives a monologue by the player's character in first person, ideally poetry discussing the nature of ascension or something like that; it should appear in a different colour or font if the windowport is capable of it. This is timed to end at the same time the portal appears, describing the character's ascension. (In windowports that uses the message area for things like prompts, this still works; the intention isn't to restrict the use of any game commands.) The basic idea is that of a cutscene which gives the player some monsters to kill while it's going on.
Because it's impossible for what happens here to affect the win/lose result of the game; this level is skippable; in a mirror of the tutorial, it can be skipped simply by pressing `<` (and a note to that effect appears before the monologue, although it doesn't stay onscreen constantly). However, what happens here can affect scoring, with a score bonus being assessed if the player clears the level the standard way (using the portal); the less help the player needed from the invicibility conditions (i.e. less damage taken, fewer status conditions autohealed, etc.), the more bonus score they get. Skipping the level also causes the player to miss out on the bonus score. (As such, it should maybe have a confirmation.)
Endgame (celestial disgrace)
If ascending correctly gives you an unloseable endgame, there's a flipside to that; donating the Amulet on the wrong altar gives you an unwinnable endgame. This is still Endgame, but all its special advantages are twisted into disadvantages; instead of good things spontaneously happening to the character, bad things do (starting out gently at first but gradually getting worse and worse). The endgame monologue is likewise much more downbeat and depressing than in the "true ending" version.
Once the player gets here, it's no longer possible to win; the portal out never spawns. (Skipping the level with `<` and attempting to quit the game also fail: this is probably worth a message like "You can't. It is cursed." in the message area even though that isn't otherwise in use. Saving the game is still supported as a simple means of quitting the game executable.) So the aim here isn't to win; it's to survive as long as possible (something that's worth score for the Endgame performance, much the same way that the player is scored on Endgame performance after an ascension).
In addition to the inability to see messages interfering with the player, there are more direct assaults on the character, both for flavour, and aimed to ensure that the character dies eventually even if every monster is defeated; all these are minor/infrequent at first and become more powerful as time goes on. Instead of damage increasing maxHP, damage reduces current HP, but maxHP reduces over time (without changing current HP) at a rate proportional to the amount of damage taken (the maxHP reduction stops while the player is undamaged); thus, damage gradually becomes permanent. Negative status effects get inflicted on the character for no reason. Items in inventory erode (even if they're normally immune to erosion) and eventually break. Likewise, ability scores decrease over time. (This combination means that even with the best possible character for surviving this sort of thing, eventually the player will end up in Ill or FoodPois status with no way to cure it remaining, and die of their sickness.)
Deaths in this version of Endgame lead to the normal death message for that kind of death, plus "(in celestial disgrace)" as a supplementary death reason.
Some voluntary challenges ("conducts"), if maintained, change the nature of the endgame in gameplay terms. (All tracked conducts also have some effect, major or minor, on the endgame monologue; ideally it should be written specifically to allow subtle changes like replacing "saw" with "heard" for a Zen player.)
The most obvious is pacifist play. This doesn't directly change anything, but it does mean that Endgame will have no monsters (because it has no list to generate from). In such a case, its progression through the levels will run very quickly (as a consequence of the lack of monsters to generate).
The game also takes care to prevent players breaking conducts in Endgame; for a foodless character, for example, any food in their inventory will disappear, monsters will leave no corpses, and the like. This is partly for gameplay reasons (breaking a conduct here would really suck), and partly for flavour reasons (the character is effectively already shaping the world around them by their choices). This also expands to preventing monsters breaking conducts the player hasn't broken; for example, a polyselfless player will effectively have protection from shape changers while on the level.
The biggest change, though, happens for an atheist character. This actually affects things a level "early"; upon arriving on Astral, the character will find it entirely empty, with only walls, floors, and doors (which are still locked); no items or monsters generate here in this version. Each of the altars is replaced with a magic portal (and all three portals go to Endgame; it doesn't matter which you take). As TDTTOE, an attempt to pray in this state will produce a message along the lines of "Nobody answered...".
For atheists, therefore, Astral is not the final "boss level" at all; Endgame is. Unlike in other branches of the game, this is now very much a real level; it's still mechanically the same, but there's no outside force helping or hurting the character, it's just them against a really large horde of monsters. The portal only appears once every monster that generated has been killed (although like before, this doesn't force the player to re-kill every monster they've killed; only a representative subset actually appear in the level). I'm currently unsure whether there should be an "ascension poem" for this case, or whether the game should just show its normal game messages. (Incidentally, this also means that for an atheist pacifist ascension, the last tricky part is on the Elemental Planes. Trying to do the new versions of those as a pacifist is likely to be nightmarish, though.)