Nonograms as an alternate puzzle branch or Sokoban replacement. This consists of a map area where items are to be placed, and burned engravings in the rows and columns to the top and left specifying the amounts of rocks to place in contiguous blobs in that row or column. There is a “stock” of some low-value item (probably rocks) that can be placed in the spots, but the puzzle will accept any item dropped on the floor.

Whenever an item is dropped or picked up from the floor, the game checks the presence or absence of an item on the floor in each square of the nonogram map, and considers the puzzle solved if the number of squares containing any amount of objects in each contiguous blob in each row and column matches its specifications.

The puzzles could be drawn from a set of stock specified puzzles, or completely randomized.

Ideas for a Sudoku puzzle system that could coexist with or replace Sokoban:

• The puzzle part of the level would be represented by an 11x11 grid (9 3x3 areas with 2 rows/columns of some other terrain to separate them).
• The solution must be given by engraving numbers on squares, with certain numbers burnt into the floor. This would require a level flag that provides 2 special cases to engravings: 1) that non-Elbereth engravings do not degrade normally, so you can write numbers in the dust without smudging them; and 2) it is impossible to erase a burnt engraving.
• The solution must be given by dropping rocks of the appropriate quantity onto the squares of the grid to represent each number.
• Both of the above solutions have the issue that the grid is practically unreadable and it basically forces the player to copy the puzzle out of the game, solve it, then copy the solution back in. One solution is to have spaces containing nothing except the requisite solution display as one of a set of 9 new glyphs that display as the number 1-9.
• Another solution is to avoid numbers and use object classes (weapon, armor, scroll, ring, wand, potion, gem, spellbook, and amulet), since there is no particular reason Sudoku has to use the numbers 1-9.
  • This means the puzzle would be solved by having 1 of each object class in each row, column, and sub-grid.
  • The “fixed” objects provided as a starting point could either be immovable, or movable but required to put back in place for the puzzle to be solved (i.e. the puzzle is checking not for any valid Sudoku solution, but a valid Sudoku solution in which the starting objects haven’t moved).
  • The main issue with this suggestion is avoiding providing the player with a bunch of free resources and not requiring them to amass 7-9 of each object class before starting. One way to work around it is to add a new object to each object class that does nothing and never generates outside of the Sudoku level, where exactly 9 of each will appear in every puzzle between the initial ones and the “stock piles”.

Searching (whether manually requested via the “s” command or automatic from the intrinsic) should automatically search any chests or large boxes on your current square for traps in addition to searching the 8 squares around you.

Corridor generation should sometimes prioritize connecting a room to an existing corridor which connects two other rooms, instead of always having to terminate at a room and ignoring corridors that already exist. This would reduce or eliminate “wide corridors” in dungeon levels formed by two nearly parallel corridors generating on top of each other, and promote more interesting level shapes where corridors have neat 3 or 4-way intersections.

Add a themed room commemorating the long-lived tactic of pudding farming. It has the following properties:

• It is a huge room, possibly a variant of the “Huge room” themed room with no subroom.
• On one space in the middle of the room is the pudding farmer, a random player monster.
  • They generate at level 15-30, as they do on the Astral Plane, but don’t have the same equipment as they would get on the Astral Plane, just the regular gear a player monster would get. Possibly some nicer gear under the assumption they’ve farmed it off the puddings.
  • They are hostile to the player, unless of the same role, in which case they are peaceful.
  • The pudding farmer also carries a thoroughly rusty -3 knife or stiletto, their Puddingbane, though it is not named as such.
  • Messages and farlook show their name as having replaced their rank title with “Pudding Farmer”, e.g. “Fred the Pudding Farmer”.
• The remaining spaces in the room have some reasonably high chance of spawning a black pudding, with varying degrees of reduced current and maximum HP.
• There may be a sink somewhere on the room’s floor, from which the initial pudding came.
• No globs of pudding on the floor from already-killed puddings; the thematic thing would be to have pudding corpses, which no longer exist in vanilla. Globs would imply the player monster has been pudding farming in NetHack 3.6 or later, which doesn’t make much sense.
• The minimum level difficulty of this room is 4, though that seems awfully low given how dangerous it’s likely to be. It could be based on the difficulty of black puddings, such as the difficulty of a black pudding + 3.
• One option to cut down on the gimmickiness of it is to have the corpse of a player monster, possibly with some gear, but not the player monster themselves, implying they slipped up and fell victim to the puddings.
• Since it was possible to pudding farm brown puddings in earlier versions of NetHack, there could be some chance that this room consists of brown puddings instead, which could then appear at a slightly lower difficulty and would lack a sink. Though this would be strange in the above case of there being a corpse rather than a player monster, since brown puddings cannot deal damage (maybe they choked?)

If the Minetown Watch are hostile and subdue you (reducing you to 0 or low HP, or possibly only if you chat to them to surrender), they throw you in jail instead of simply killing you. This probably takes the form of a special jail level where you start out having regained your HP but have lost most or all of your possessions. The jail level is staffed with more watchmen (it could also be guards, but those are specifically guarding vaults).

There could be a variety of ways to escape:

• solving a special puzzle involving moving iron bars or walls and levers/buttons
• bribing or seducing the guards
• using stealth to sneak past the guards
• or just waiting a certain amount of time without dying.

Allow for gas clouds of different types (confusion gas, sleep gas, hallucination gas, etc) by passing an additional argument to create_gas_cloud.

Clouds of sleep gas would immediately have a use in Nazgul and orange dragon breath attacks, which are already described as such. They might also be useful for sleeping gas traps, which would emit an actual cloud of sleep gas. Depending on implementation, the sleep gas cloud could have only a chance of inducing sleep rather than always knocking you out, which could make it tactically interesting to navigate/teleport/etc rather than just getting put to sleep and having the cloud gone by the time you wake up.

Water elementals’ HP (and Pw, if applicable) regeneration is boosted when they are on a water-containing space such as a moat or a fountain. Possibly, they can also suck up the water to regain a large quantity of hit points at once, which removes the water terrain if it is expendable (a fountain or pool or puddle of shallow water will dry up).

In order to make them more interesting in combat, their AI may favor hanging around sources of water and trying to find a path to the nearest water when they are injured.