Cave-in trap, which appears deep in the dungeon and/or in Gehennom. It causes the ceiling to collapse all around the target, turning the spaces into stone terrain, burying the target (potentially starting suffocating timers) and dumping a few boulders and rocks in the vicinity. It works somewhat like GruntHack cave-ins on the Plane of Earth, but in trap form.
Grease trap, which showers you with grease when triggered, greasing your wielded weapon and giving you slippery fingers and several turns of fumbling. Occasionally, your armor may get randomly greased.
May drop a can of grease with 0-2 charges when untrapped.
If #3671 (greasy floor) is implemented, the grease trap may automatically replace itself with the greasy floor trap or terrain as part of its effect.
Deeper in the dungeon, rust traps might target your pack instead of your armor or gear, and could possibly be renamed to “water trap”. On deeper levels and particularly in Gehennom, rust traps phase out to be replaced by acid traps. These deal corrosion and acid damage (and quite a bit of it, like having multiple potions of acid dumped on your head).
Greasy floor, a new type of terrain (or perhaps a trap?) that applies grease to any boots you are wearing and almost always makes you slip. Slipping on greasy floor (which can also happen by walking barefoot or with already-greased boots on) causes you to drop random items, some of which may get greased.
The player can create greasy floor by smashing a potion of oil or applying (multiple?) charges from a can of grease to the floor.
Creatures that move onto a greasy floor patch may “slip and slide and struggle to stay upright”, losing their next turn 70% of the time. This also happens to a creature standing on a greasy floor patch that tries to do something involving footwork (combat, moving off the square, etc) 30% of the time. Or for a more simplified implementation, the trap doesn’t have to cause loss of turn when moved onto (though it might still produce a message), but has a 70% chance of making the creature lose its next turn regardless of the action (still need to keep your balance to take out a scroll to read or zap a wand, for instance).
If implemented as a trap, it cannot be untrapped (except probably by the standard method of digging a pit on it), but will eventually wear out after a slightly randomized number of times it affects something. (This prevents you from setting a single one in Ludios and then standing back to watch the whole army get greased and fall over themselves.)
Boxing glove trap, a trap that hits the victim with a boxing glove (for stunning, potentially?). When untrapped, it can produce a random pair of gloves, biased towards normal leather gloves and maybe away from fumble gloves.
A new type of trap called a “conduct trap” that spawns in Gehennom. Triggering one causes Moloch to enforce one of the in-game conducts on you for the rest of the game, or until you next break it, even if you have previously broken it. Breaking it after this happens makes Moloch mete out some sort of harsh punishment.
Moth larvae trap, which destroys cloth items you are carrying such as bags, cloaks, blindfolds and towels.
Quicksand, either as a trap or terrain type (they both have advantages and disadvantages); stepping in makes you start sinking in like with lava, and if you don’t find some way to get out in time, you suffocate to death.
Corpse traps, which act like statue traps but instead revive a corpse that is on that square when the player steps onto it or otherwise interacts with the corpse.
New magic beam trap, which fires a magic beam (probably implemented as a magic missile ray, or possibly a random ray type) from a fixed point several squares away in one of the eight directions towards the trap square.
Internally, the fixed point is stored in the trap’s launch coordinates, and the ray type should probably be stored as the appropriate wand type in launch_otyp.
Spring trap, like the reverse of a trapdoor: stepping on it bounces you up through the ceiling into a higher level, or alternatively just makes you crack your head on the ceiling.
Temporary pit trap: it fills itself in after a certain number of turns. A monster in it will be buried. It could either use a timer to decide when to fill itself in, or be tied to the monster id of its creator, triggering after a certain amount of time if the creator is still on the level. Also a good candidate for creating during an earthquake, rather than a permanent pit.
Add an electric trap, which zaps players or monsters who trigger it. Can also destroy rings and wands with shock damage.
A trap or monster (or possibly change sleeping gas traps or homunculi to this) that causes “sleeping poison”: it starts a very short intrinsic restful sleep timeout, so you don’t fall asleep immediately but have a little time to react.
New container traps:
Traps that shoot out potions. Generate with a variety of negative potions such as sleep, acid, lit oil, hallucination. (Or possibly, they only generate with 1 or 2 potions, because then the player will go over and untrap it for any remaining potions.)
Would work best if the trap struct contained an object pointer for ammunition, as described in #768.
Remove the odd feeling messages from magic traps. Instead move them to a new trap, a “foresight trap”, which gives you a vision of something to come. Once triggered, the trap vanishes. Effects can be:
A floor trap that sounds a loud alarm, waking monsters (a lot more so than a squeaky board, perhaps level-wide).
New container trap effect, a loud alarm that wakes nearby monsters. (Exploding chests already wake nearby monsters, but the chance of it happening is miniscule unless your Luck is below -7; this was proposed as one of the common effects even at high Luck.)
Mud terrain, brown }. It can be walked on, but if you stand in one spot for long enough you will start sinking into the mud. You will be able to pull free if you are only a little stuck, but once you get more stuck you cannot, and if you cannot extricate yourself somehow you will eventually sink below the surface and suffocate.
This might best be implemented with a new “mud pit” trap, which gets created by standing on mud for too long and works similarly to a regular pit in that you are held in the same place by it for a while as you try to move out. Except a mud pit allows you to sink down and suffocate.
New container trap effect: a monster is generated from the box (was hiding in the box and pops out at you), taking you by surprise. It gets a free attack on you.
If you have egg on your face, your Charisma is temporarily and sharply reduced, lasting until either you get hit by or immersed in water or #wipe with a towel. This could also apply to having cream pie on your face.
A possible addition is for monsters to throw random (non-cockatrice) eggs at you.
Another possible addition is to add a new “egg trap”, which fires eggs at you with the intention of getting egg on you.
Pressure plate traps that cause all the doors of the current room to close and lock (doorways without doors could turn into iron bars or, on deep enough levels, all doors could turn into iron bars). Triggering this automatically removes the trap. Generated very rarely, and has special generation that occasionally makes it appear just inside a door to a throne room.
Alarm trap on doors: it makes a noise to alert nearby monsters, and also summons a squad of ogres or Kops or whatever on one of the stairs.
Caltrops: a nonmagic stackable tool that when applied creates a “caltrop trap” on your space, which damages / immobilizes / slows the first monster to enter it. Rangers and rogues excel at using them and possibly get some bonuses from them. Not difficult to untrap, though it would be nice if some caltrops could gradually be lost in the process. Maybe spreading caltrops consumes five or so of them, and you won’t always get five back during an untrap.
Add nets, on the basis that NetHack needs to have nets in it. You can throw them in pools to fish with, and throw them at small monsters to trap them in place. There could also be a trap that catches you in a net. You can also mess up throwing them and tangle yourself instead. Possibly, nets would be their own skill too.
For simplicity of implementation, they should create a temporary web on the player’s space (with a flag set so that it uses “net” in its messages instead of “web” and is probably harder/impossible to tear through at high Strength). Either nets would generate in stacks of 11-20 and get destroyed when the monster escaped the net, or they would drop themselves (most of the time) when the monster escaped the net and destroyed the trap. Either way, they should be fairly light.
Wind trap: when you step on it, your wielded weapon and any items on the square are blown upwards by a gust and fall back on your head.
Mummy traps, a new trap type that generates with a very desirable item: highly enchanted gear, magic markers, items with object properties, etc. However, when you pick it up or interact with it in any way like teleporting it or having a pet collect it, a bunch of mummies appear around you (they would obviously need to be more threatening than they are right now). Also can have a “mummy room”, a special room that contains one mummy trap and nothing else.
Magnet traps that attract metal items out of your inventory, but also attract loadstones and are a means of getting rid of them.
