Special (or themed) rooms in Gehennom containing priest and monk corpses, to correspond to the themed room that contains a bunch of dead bodies with no priests and monks because a comment notes “Moloch has a special fate reserved for members of those classes.”
New special room “cursed graveyard”. Its initial generation is the same as a regular graveyard. The difference is that it generates undead monsters on open spaces in the graveyard (with messages like “A zombie claws out of the ground!”) at a much higher frequency than normal, so long as there is still a gravestone existing within the graveyard. When all gravestones in the graveyard are destroyed, the room converts to a normal graveyard and undead stop spawning.
Gravestone texts in a cursed graveyard don’t draw from the regular pool of gallows-humor messages. They instead use a separate pool of ominous, vengeful, and threatening messages.
Regular gravestone-destroying penalties do not apply if the gravestone being destroyed is in a cursed graveyard.
Priests can destroy a headstone in a cursed graveyard by #turning while standing on it.
Abandoned temples can generate as a special room, or else a room containing a random unattended altar may be converted into an abandoned temple.
Gehennom special room “ice cavern”, with mixed ice/regular floor, possibly with unnethack-style irregular ice walls, and containing ice devils and cold-themed items like wands of cold and rings of fire resistance.
Spider nest room; a zoo-type room (where every square generates a monster independently) with giant and cave spiders. Each square additionally has a 70% chance of a web. Loot consists of several “bones piles” that have a few random objects but no comestibles.
Special “cell” room. Only valid if one end of the room has no doors. It generates a line of iron bars across this end of the room, with a locked (iron if possible) door somewhere in the line. Independently, it may contain: a prisoner, a sink, a bed (if those exist), and 1-2 chests with random contents.
If cauldrons are added, new special room that contains several gnomish wizards, orc shamans, and kobold shamans standing around a cauldron.
One Gehennom “special room” should be an active temple with a peaceful priest of Moloch.
Storeroom: a special room that only generates in a dead end room, perhaps only if the room is under a certain total area. Contains 2-4 chests or large boxes, and rarely ice boxes. If the game had barrels, it should have some of those too. May contain a couple rats too.
New special room “lich hall”. Contains one difficulty-appropriate or somewhat-out-of-difficulty lich, generated asleep with difficulty-appropriate undead. One or two statues generate along the walls, and there are several spellbooks on the floor or in chests. Within the hall, the lich can summon more undead.
Forest rooms, which contain a scattering of trees.
Slaughterhouses as a Gehennom special room, filled with corpses, leashes, and knives.
Implement farming, in certain special rooms called greenhouses. Allows you to grow fruits, carrots, garlic, trees, etc.
Challenge rooms that occasionally get embedded into Gehennom levels. They are sealed off somehow, perhaps with solid stone you need to dig through to enter. They are not intended to be required, and contain some sort of reward. Rooms might include:
Special room that is lined (not filled) with statues of you, and contains no monsters, items, traps, or anything else interesting. All doors in contain traps that will make them lock behind you. Intended only to make the game more creepy.
Special room that contains a demon gate in the center. This continually spawns monsters who try to defend the gate; the player has to make it through the spawns to destroy it or block it off. The gate could be implemented as a magic portal to a special challenge level like an ADOM-style vault.
New special room “rat nest”: generates very high in the dungeon, and contains some r, some eroded/negatively enchanted armor, and some comestibles.
Pool rooms, a special room type that consists of a perimeter of normal floor surrounding a region of water taking up the rest of the middle of the floor. It is populated with sea monsters and some sunken treasure. It could also contain a fake bones pile, a pun on “bones pool”.
Services center: a shop containing shopkeepers who offer services but have no goods to sell.
Special room “ruined church” that contains ghosts, pieces of glass scattered around the floor, maybe an altar, maybe a spellbook, and blank paper/scrolls of junk mail scattered around the floor.
