Developers Foresight / NetHack

There's a reason why "The DevTeam Thinks Of Everything" is a popular phrase among the NetHack community: the DevTeam tends to program even obscure interactions that a reasonable player would never find.

• Touching a cockatrice with bare flesh causes instant petrification.
  • The player can polymorph briefly into a random monster, gaining all its abilities. There are magical items that let you control your transformation, change gender or remain in a form indefinitely. Female snakes, birds and dragons can lay eggs. Conclusion: whilst playing as a female character, polymorph into a cockatrice, lay dozens of eggs, revert to human, and throw the eggs at enemies to petrify them instantly!. You get a luck penalty for breaking eggs you laid yourself however, to discourage heavy use of this somewhat cheesy tactic.
  • A cockatrice corpse can be wielded as a weapon (if you have gloves, of course), which will handily petrify enemies... until it starts to rot. But, as with all corpses (and other food items), you can dip it in holy water to bless it, which keeps it fresh for much longer.
  • Also, if one falls down a staircase while wielding a cockatrice corpse, bad things tend to happen...
  • Perhaps the best example of this involving cockatrices is this. When you are blind and walk over an item, the game states "you try to feel what is lying on the floor. It is a [item]." This is literal; if you walk over a cockatrice corpse while blind and bare-handed, "you turn to stone..."
  • Touching a cockatrice corpse without gloves will also instantly petrify the player if the cockatrice corpse is in a container (chest, box, sack, bag of holding, oilskin). This has killed at least one player on the Astral Plane, who blinded themself to use Telepathy, took off their gloves for some reason, then searched in their Bag of Holding.
• Engraving Elbereth on a square and standing on it will stop monsters that respect Elbereth from attacking you in melee.
  • Therefore, such monsters with ranged attacks will switch to it while you stand on it, unless you engrave Elbereth while being adjacent to said monsters, causing them to flee. Monsters already fleeing from Elbereth will not attack you, even if they have ranged attacks.
  • Beware, blinded monsters can't see Elbereth, so they will NOT respect it.
  • Elbereth is case sensitive. It will still work if you write in minor cases, but if you write it with proper capitalized E, you will exercise wisdom.
  • There is a condition in engrave.c that prevents gravestones from warding monsters — in case someone names themself Elbereth, dies, and leaves a bones file, their gravestone won't conveniently serve as a permanent Elbereth.
• As a minor example, reading a cursed scroll of amnesia causes you to forget everything with the phrase "Thinking of Maud you forget everything else." or "Who was that Maud person anyway?" If your character is named Maud, the phrase is instead "As your mind turns inwards on itself, you forget everything else."
• Try to dip a potion into itself and you get told "This is a potion bottle, not a Klein bottle!"
  • In a similar fashion, attempting to put a bag inside itself produces the response that "That would be an interesting topological exercise."
• If you try to flash a camera underwater, you're told you can't do that because it would void the warranty.
• Trying to apply a saddle to a succubus abuses your wisdom and produces the message "Shame on you!"
• "Thou hast angered me." If you anger a god enough to earn divine retribution, you will be zapped with a fatal lightning bolt. If that fails, you are zapped with a wide-angle disintegration beam. If that fails, the god says "I believe it not!" and gives up (except in the final level, where it gets even angrier and summons minions to attack you). Although you can survive these with a ring of shock resistance and black dragon scale mail (which provides disintegration resistance), you can also survive by being engulfed by a monster: the beams will hit the engulfing monster before they hit you. If the monster has shock resistance, but not disintegration resistance^note No such monster exists in the vanilla game, but the code is in place anyway, just in case you try modding., it will survive the lightning bolt, but die to the disintegration beam, freeing you. And then you get experience points for pulling that off. But don't think you can keep a pacifist conduct this way.
• Using a stethoscope toward the south (the 'j' direction) while on the bottom line of the screen results in the fourth-wall noting line, "You hear a faint typing noise".
• Getting acid wet (by trying to #dip a potion of acid into a potion of water, for example) causes it to boil and harm the player. If this kills the player, their tombstone will list the cause of death as "elementary chemistry". This is notable in that most causes of death are reported in a matter-of-fact manner approaching Deadpan Snarker-levels ("killed by a grid bug while helpless", "killed by kicking a stethoscope", etc.), so one would be forgiven for not expecting a Take That! directed at the player.
  • You can also be "killed by elementary physics" by throwing something upward (<) while not wearing a helmet; the object will hit you on the head on its way back down and inflict damage. If the object you threw upwards while bare-headed was a cockatrice corpse, your cause of death will be "petrified by elementary physics."
• Vaults full of gold are occasionally found sealed off from most of the dungeon. If you connive your way inside, a vault guard will appear to investigate. In most cases, he'll demand your name; most answers will lead to the guard demanding you leave all the money behind in the vault as the guard seals it back up. If you tell the guard that you're "Croesus" (alternate translations "Kroisos" and "Creosote" can be found acceptable as well), the guard will leave without incident. If you're a lawful-aligned character, you receive a small alignment penalty for lying, unless you actually named your character Croesus, in which case no penalty is incurred. If you try to pass yourself off as Croesus after you've gone to Fort Ludios and killed him, the guard gets angry and attacks. If you're unable to speak (e.g., an amulet of strangulation is choking you), the guard leaves. If you're mimicking an object (most likely having eaten a mimic's corpse, turning you into a pile of gold), the guard also leaves. If hallucinating when you eat a mimic corpse, you turn into an orange. The guard leaves puzzled, wondering "who left that orange in here". And if you're polymorphed into a small enough monster, you can hide under the gold and puzzle the guard again. If you're changing body armor (which can take four turns, or longer), the guard leaves commenting that he'll return when you're not busy.
• The game is riddled with unique messages that trigger under very specific circumstances:
  • Polymorphing into a monster that can eat metal and eating a trident gives the message "That was pure chewing satisfaction." It's a reference to Trident Gum, though the slogan is actually for Wrigley's Spearmint gum.
  • Another one: eating a flint stone would result in the message "Yabba-dabba delicious!". Currently no monster can eat rocks, so this isn't actually seen. Post Pebbles cereal, which features Fred and Barney from The Flintstones in its commercials.
  • Trying to write with a venom triggers a unique message. It is nearly impossible to see it within the course of the game, since Venoms only exist as items in wizard mode, and it is unlikely that a person would think to use venom for writing.
  • The game comments that the player is literally beating a dead horse when the player uses a bullwhip on a horse corpse.
• If you eat too much, you choke and die. Makes sense. Unless you're wearing an Amulet of Magical Breathing. Also makes sense!
  • What happens then is also logical: having overeaten, your character will then vomit up the food they physically cannot stomach.
• Speaking of amulets of magical breathing, the polar opposite is the amulet of strangulation, which kills you in five turns unless you can get it removed. But what about the "unbreathing" property (from equipping or eating an amulet of magical breathing, or polymorphed into a creature with the property)? The amulet strangles you anyway because the constricting action cuts off the blood supply to your brain, with different text to match!
• If you see a pit viper or pit fiend fall into a pit, you get the message "How pitiful! Isn't that the pits?"
• They even do this in the download! "Step 0: Promise to do step 2 before telling us the game won't run. Thank you."
• Eucalyptus leaves can be eaten to cure food poisoning, as intended. Or, you can Apply the leaf instead of Eating it to use it as a noisy grass whistle. This also has a chance of removing the blessing from a blessed leaf, because seriously, you just put your mouth all over it.
• The infamous Floating Eyes cannot counterattack while blind, but the player has a chance to lose luck while finishing the Eye off because beating up blind people isn't cool.
• With some "luck", it is possible to kill yourself on turn 1 (e.g. as a knight, slip off your saddled pony trying to mount it or zap an attack wand at yourself). The resulting message: "Do not pass Go. Do not collect 200 zorkmids."
• Zapping a cream pie with a wand of striking gives the message "What a mess!" and destroys the cream pie. Applying a cream pie will blind you for a few turns, as your character just shoved their face into a cream pie.
• The spell of "turn undead" causes undead creatures to flee, as per Dungeons & Dragons. What does a Nethack "wand of undead turning" do?
  • Why, makes undead run away, of course... and also resurrects corpses. ^note  It turns them un-dead.
  • And if you happen to be undead, it will stun you if you hit yourself.
• The Mail Daemon delivers mail to the player. He spawns, delivers the mail, and vanishes in one turn. However, you can wish for a statue of a mail daemon, cast Stone To Flesh, and the Mail Daemon will spawn, say "I'm late!", and vanish.
  • As a side note, if you're good enough, you might be able to kill this Mail Daemon before it vanishes. Doing this will genocide the mail daemon and prevent you from receiving any mail in the future.
  • Unlike normal scrolls, scrolls of mail can't be blanked or polymorphed (in order to prevent exploits by sending yourself dozens of mails and turning them into something useful).
• The Quantum Mechanic monster is basically one big physics joke. Its attack will randomly teleport you, and eating a Quantum Mechanic corpse will give you the intrinsic speed ability (or remove intrinsic speed from you if you were already fast). Upon death, the Quantum Mechanic also has a small chance to drop a box. When you open the box, a cat named Schrödinger's Cat will be found inside. 50% of the time, the cat will be alive, and 50% of the time, the cat will be dead. What brings this into Developer's Foresight territory is that if you look at the game's source code, you discover that unlike every other box in the game, the state of the box's contents (whether the cat is alive or dead) is not determined until you open the box and look.
• As a knight (who starts with a pet pony), play the game without a default horse name set and don't give it a name. If you go up on the first level with your horse, you're told that you've "been through the dungeon on a horse with no name". Dismounting an unnamed steed while hallucinating generates the message "It felt good to get out of the rain."
• Removing a blindfold while blind for some other reason results in the message "You were wearing a blindfold. You still cannot see".
• Certain classes of objects have randomized appearances. For example, a "spiky wand" might always be a wand of death in one playthrough, and always a wand of cancellation in the next. However, there are certain ways that the appearance itself is meaningful, regardless of what the item actually turns out to be:
  • A smoky or milky potion might spawn a djinni or ghost, respectively, when quaffed.
  • Marble wands are affected by Stone To Flesh. Glass and crystal wands shatter when hit with a force bolt. Metal wands can rust. Copper wands can corrode. Silver wands can be wielded to do silver damage.
  • Rings set with hard gems can be used to engrave messages. And rings made of stone or gems can be turned into meat rings via the Stone to Flesh spell. Wearing a silver ring and attacking monsters bare-handed will cause silver damage, as long as you're not wearing gloves.
  • "Riding Boots" give a bonus to successfully mounting a steed, and "Snow Boots" prevent you from fumbling on ice (if the Snow Boots happen to be Boots of Fumbling in your game, they'll still negate the fumbling effects of the ice, but not their own effect).
  • The "Visored Helmet" will protect you from the raven's blinding attack and from the spitting venom of cobras.
• Here's a quick list of some of the more ingenious^note And deliberate. So no bugs like "drowned in a drowning" or "turned to slime by a scroll of genocide." death messages, along with spoiler'd instructions on what causes them:
  • Dragged downstairs by an iron ball. You were punished, a status effect which afflicts you with a ball and chain cuffed to one ankle, and you walked in such a way that your iron ball fell down a staircase and dragged you along behind it with fatal effect.
    • Crunched in the head by an iron ball. You fell in a pit or trap-door while punished, and your iron ball fell on top of you.
  • Squished under a boulder. You were in a pit, and a boulder was rolled or thrown on top of you.
  • Petrified by deliberately meeting Medusa's gaze. You were polymorphed into a monster that had a gaze attack, and you attempted to use it on Medusa.
  • Petrified by trying to help a cockatrice out of a pit. Pretty self-explanatory, but still demonstrates the trope.
  • Killed by dangerous winds. You were levitating over a Sokoban hole, which yanks you out of the air to prevent cheesing your way past the puzzle, and were killed by the fall damage.
  • Killed by wedging into a narrow crevice. You were carrying more than 600 weight of items, and you threw an item while levitating in such a way that Newton's 3rd Law forced you through a diagonal space between two walls.
  • Killed by an unsuccessful polymorph. You polymorphed into a form that would have had 0 or less max HP.
  • Killed by a residual undead turning effect. You polymorphed into an undead monster and prayed to a non-chaotic god, causing him/her to kill you.
  • Suicide. Try to teleport to level 0.
  • Went to heaven prematurely. Try to teleport to level -10 or higher.
• For some scrolls and potions, if you use them when you don't yet know what they do and there's nothing available for their effects to act upon (like drinking a potion of monster detection when there aren't any monsters on the level), then you'll get the message "You have a strange feeling for a moment, but it passes". But if this happens while you're hallucinating, you get the message "You have a normal feeling for a moment, then it passes".
• Get hit with a Finger of Death spell while polymorphed into an undead creature and the game informs you that "You seem no deader than before." Get shot with a Wand of Death and it notes that "The wand shoots an apparently harmless beam at you."
• If, when trying to bribe a demon lord to leave you alone, you enter a negative number as the amount of gold pieces to give, the demon attacks you for trying to short-change it.
• Armor (shirts, body armor, and cloaks) must be put on in the specific order of shirt first, then body armor, then cloak. They must also be taken off in the reverse order. If you're wearing, say, a cursed cloak, you can't unequip the armor under it, and you can't put any armor on over it.
  • Also, cursed equipment cannot normally be removed in any way other than uncursing them. However, if you are wearing, for example, a cursed armor and you physically change form, such as drinking a potion that transforms you into a dragon ten times your original size, the cursed armor will break and fall off.
    • Speaking of polymorphing into a Dragon, if you are wearing (magical) Dragon Scale Mail, you will polymorph into a dragon of the colour of the DSM you are wearing, and this will not destroy the armor.
• If you're blind, gaze attacks will have no effect on you. Which means that there are occasions where the aforementioned smashing a cream pie into your own face can be a viable battle tactic.
• If you are blind, hallucinating, confused, or polymorphed into certain monsters, almost every single message in the game has a unique variant to account for your altered perception, such as describing the sounds instead of the visuals. Sometimes there are four or five different versions for if you have multiple effects at the same time.
• In addition to the effect they have when used normally, most wands give special messages when engraving writing onto the floor, which can be used to help identify them. Some even have extra effects.
  • A Wand of Cancellation or Make Invisible will make any pre-existing engraving vanish. A Wand of Teleportation will teleport a pre-existing engraving somewhere else on the level, with the same message. A wand of Polymorph will change the existing message to a random one. None of these will give any special message if the floor was already blank.
  • Fire and Lightning cause permanent engravings as opposed to the temporary engravings from other wands. Lightning will blind you for your efforts.
  • Sleep and Death both give the same message, "The bugs on the <floor> stop moving!", so you can't tell them apart until you use it on a monster.
  • Cold, digging, magic missile, striking, slow monster, speed monster, and an empty wand will all have unique messages of their own.
  • Wands which don't care where you point them, like Wishing and Light, give their normal effect.
• The wand of cancellation, which un-magics items and removes many monsters' special attacks, has many special rules attached to it.
  • It turns most potions into water, but turns a few specific ones into fruit juice instead (as does the unicorn horn) and doesn't change booze, juice, or oil at all.
  • If you try to put it in a bag of holding, you'll destroy the bag. (Same if you try to put one bag of holding inside another.)
  • It will have no effect on another wand of cancellation or a spellbook of cancellation.
  • If you use it on a clay golem, the golem dies instantly (a reference to the original folklore).
• Dipping an amethyst into a potion of booze will turn it into a potion of fruit juice (which is a reference to old folklore about amethyst curing drunkenness).
• If you're slimed, and thus in the process of turning into a green slime, polymorphing into a green slime cures you. Or rather, it speeds up and finishes the transformation, but makes sure you won't become a mindless monster in the process.

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You hear a faint clicking noise.