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Video Game / NetHack

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You see here a blessed scroll of identify. 
i - a blessed scroll of identify. r
What do you want to read? [ijklm or ?* ] i
As you read the scroll, it disappears.
This is an identify scroll. —More-
What would you like to identify first? nethack

NetHack is old. The first version came out in 1987.
NetHack is complex. It can take years of play to see it all.
NetHack is random. It is one of the three founding roguelikes and will sometimes generate levels that seem flatly impossible. But they never are.

NetHack has been described as a puzzle game hiding inside a roguelike's skin. Whereas the archetypal Angband or Dungeon Crawl hero is a Knight in Shining Armor who slays countless evil creatures and becomes powerful like unto God, the archetypal NetHack hero is a cunning trickster (or...hacker) who sets traps, fights in unconventional ways and never, ever plays fair. After the very first few levels, killing monsters for XP becomes unprofitable (or even disadvantageous). Instead, power comes from your ever-expanding collection of items which can be wielded, worn, thrown, rubbed, dipped, engraved, snapped, pointed, cast, eaten, read, or applied, singly or in combination.

The advantage of NetHack`s focus on items is that it reduces the impact of luck. By carefully hoarding your resources, (almost) nothing is inescapably fatal. The downside of NetHack's focus on items is that it reduces the impact of luck. Once you've learned some effective tactics, multiple victories can start to feel similar, or even repetitive.

Still, for a free game (in the sense of both "free beer" and "free speech") that can take up to a decade to beat for the first time, you could do worse.

NetHack is cross-platform; it's safe to bet that if you're using an operating system that's still being developed (and even if it isn't), there's a port for it. In fact, Linux distributions tend to feature ports of it in their software repositories, and anyone with the proper programming skills can make ports or modifications because it is free and open-source software, released under the terms of the NetHack General Public License, a precursor to the GNU General Public License.

You can play it online here, and get it for Android OS here.

If NetHack's rather archaic graphics intimidate you, you can always try Vulture, an isometric GUI that more or less takes the original and spits out detailed graphics, sounds, and all-around allows for an easier experience, when learning how to play. The site currently has builds for vanilla NetHack, SLASH'EM and UnNetHack, with the SporkHack variant coming soon.note  Additionally, the NetHack Wiki has a list of other alternate graphical tilesets.

Note: The NetHack community's definition of "spoiler" is a bit different than the usual; here, "spoiler" refers not just to plotline spoilers, but gameplay-related ones that can render ascensions and overall playing experience easier. You probably won't spoil much of the Excuse Plot by reading behind the spoiler tags, but you will probably ruin the challenge for yourself. If you wish to experience as much of the challenge as possible, tread carefully around the spoiler tags.

There is a large box named "Tropes" here, loot it? [ynq] (q) y
You carefully open the large box...—More—


  • Acronym and Abbreviation Overload: The IRC channel for NetHack often combines this with the in-game symbols used to represent the various items; so a late-game Ascension kit might contain (among other things) [oMR, "oLS, a cursed !oGL and plenty of /oD.note 
  • Acquired Poison Immunity: And many other types of immunities besides.
  • Adam Smith Hates Your Guts: Shops charge more if you're hungry, are a tourist, have really low charisma, or are wearing a Hawaiian shirt.
    • Inverted with characters who have very high charisma (even low level tourists wearing a Hawaiian Shirt). They get discounts.
  • All Animals Are Dogs: The only way to tame most monsters is by reading a scroll of taming or casting charm monster (or in some cases by wishing for a figurine), but throwing food (especially treats) to an already-tamed monster will increase their tameness, regardless of what kind of animal it is (as long as it's food they'll eat).
    • And if the monster is a domestic type, (cats, dogs, horses) you can throw food at the non-tame ones to tame them. If you throw food that they don't eat (fruit to cats and dogs, meat to horses) then that will make them peaceful if they were hostile, and hostile if they were peaceful (due to them being irritated at you pelting them with food)
  • All Cavemen Were Neanderthals
  • All There in the Manual: The in-game guide is a remarkable collection of quotes and information, not all of which is entirely accurate in describing game mechanics.
  • Ambiguous Syntax: If you #chat with one of the Riders, they'll say "Who do you think you are, War?" (9/10ths chance with Death.) Either you are War, or it's a Pretender Diss. A source code comment clarifies that it's the former.
  • Amplifier Artifact: The Magic Mirror of Merlin gives Knights (and Knights alone) double damage to most of their spells.
  • Anachronism Stew: Let's see... playable characters include an Indiana Jones-inspired Adventurer Archaeologist, a Conan the Barbarian-style Barbarian Hero, a caveman, a Samurai, and a Hawaiian-Shirted Tourist complete with a credit card (used to pick locks). Items and enemies include traditional staples like Dragons, Demons and Giants, but also included are things like Grid Bugs, Quantum Mechanics, and Jabberwocks. Finally, plastic, while fairly uncommon, isn't unknown either.
  • Ant Assault: Ants appear as common monsters, represented by lowercase a glyph together with bees and giant beetles. There are three types of ants in the game: giant ants, the weakest variant of ant enemies; soldier ants, which deal high damage and can poison your character; and the fire ants, which can set the character on fire. They all are very quick and tend to appear in large groups, making them very hard to deal with.
  • Anti-Frustration Features: The renamable food (named "slime mold" by default) is classified as vegan food, even if you name the food to be something that's obviously a meat product (such as "cheeseburger" or "prime rib"), so as to be easier on players going for a vegetarian or vegan conduct.
  • Anti-Magic: Magic resistance, a property given by a few rare items, has this effect. Since it neutralizes unintentional polymorphing, "pure magic" attacks (including Wands of Death), and many other nasty things, it's extremely useful.
    • Also the mechanic of "cancellation", which removes special abilities from monsters and turns almost all items into mundane equivalents (potions of water, blank scrolls and books, dead wands, etc, and it removes all enchantments and bless/curse status). And if you're not careful, you might have it done to your entire inventory at once (Although this is a great way to decurse the inventory of a Bones file).
  • Arbitrary Skepticism: Invoked by players doing Atheist conduct — never pray or otherwise interact with gods — despite the goal of the game being to retrieve an amulet for your god and become a demigod yourself. This gets particularly confusing when you are playing as an Atheist priest, a class centered around religious themes.
  • Artifact of Death: Try to use an artifact under the wrong circumstances (like being the wrong alignment) and it may "blast" you, possibly killing you. Also, though not really an artifact, weaponized cockatrice corpses can turn most enemies to stone with a single smack; but of course they can also turn you to stone if you're not extremely careful.
  • Artifact Title: By modern standards, the game's name is nonsense. It has nothing to do with a network, the internet, or hacking. It's actually a port of the older game Hack open-sourced and developed on the (then shiny new) internet.
  • Artistic License – Biology: The game's concept of "nutrition" is probably the wackiest thing of all; unless you find a Ring of Slow Digestion, you'll need to eat the equivalent of dozens of dragon corpses to complete the game without starving — even if you're a gnome — but drinking is entirely optional and Nobody Poops. Specific tropes:
    • All Animals Are Dogs: Tamed beasts all act like loyal canines: they follow you around, attack perceived threats to their master, can be put on a literal leash, and so on.
    • Diurnal Nocturnal Animal: Animals only sleep in special circumstances that have nothing to do with time of day (even though the game does check the time of day for other reasons).
    • Imprinting: If an egg hatches while you're carrying it. For double the artistic license points, the odds of it happening depend on the gender of your character.
    • Misplaced Vegetation: Minetown — a cave, inside a dungeon — sometimes has trees. (Although their positioning would indicate they were deliberately planted there as decor.)
    • More Predators Than Prey: There are lots of carnivores, very few herbivores, almost no plants, and no sunlight. Animals generally don't need or want to eat anything unless you've tamed them.
    • Psycho Electric Eel: A major hazard of watery areas.
  • Ascend to a Higher Plane of Existence: What happens when you win.
  • Auto-Revive: The amulet of life saving. Unless you genocide yourself or have your brain eaten by a mind flayer. And it doesn't do much to remove the source of the death, either...
  • Bandit Mook: Leprechauns and nymphs are primarily interested in your gold and inventory items, respectively. They also like to teleport away after stealing something, which complicates retrieval. Nymphs can even steal cursed weapons/armor/etc. welded to you and can undo chains attached to you, which makes them useful for removing such items. Just remember to put away anything dangerous first....
  • Bare-Fisted Monk: Despite not being able to effectively use weapons, monk characters can become extremely powerful and deadly. (Sadly, a bug makes them deal 1 point of damage 25% of the time.)
  • Basilisk and Cockatrice: Cockatrices appear here. If you hear the cockatrice's hiss or are touched by a living cockatrice, there's a chance that you'll slowly start turning to stone; this can be cancelled by eating a lizard corpse or eating/drinking something acid. Touching a cockatrice (living or dead) with your bare skin will instantly turn you to stone. Gloved characters can take advantage of this by picking up a cockatrice corpse and using it to bash monsters. But keep in mind that gloved monsters can also pick up a cockatrice corpse and use it against you.
    • The variant Slash'EM also has the basilisk, which is basically the same as the cockatrice, except that it doesn't hiss and its corpse is too big to use as an Improvised Weapon.
  • Bear Trap: These can be encountered as a hidden trap, which do some damage, but more annoyingly hold you in place for a few turns until you pull free. You can also disarm them, lug them around and re-set them to be triggered by monsters.
  • Bigfoot, Sasquatch, and Yeti: Sasquatch and Yeti are both hostile creatures you can encounter in the dungeon. An eaten Yeti corpse can supply your character with cold resistance.
  • Binomium ridiculus: Coyotes in the game are naturally labeled in this fashion. However, cancelling them turns the name into the real species name, Canis latrans.
  • Blindfolded Vision: Possible with Telepathy, and invoked by Intrinsic Telepathy.
    • In fact, blinding yourself while you have telepathy protects you from many forms of visual attacks. The downside is that it makes you more vulnerable to mind flayers, you can't see mindless creatures like undead, and traversing unexplored parts of the dungeon is more annoying.
  • Blinding Camera Flash: There exists an "expensive camera" item, the only use of which is this. It's also one of the very few things that can make the Riders flee from you.
  • Block Puzzle: Sokoban, a four-level puzzle in which you push boulders to plug holes in the floor. The game mechanics change somewhat, though: You can't push the boulders diagonally or fly over the holes in the floor, and trying to cheat (by creating/destroying boulders or trying to bypass the pits at the end of each level) nets you a Luck penalty.
  • Bolt of Divine Retribution: Tick off your god enough, and you'll get struck by lightning.
    • If you manage to survive that, the deity will then blast you with a wide-angle disintegration beam ("wide-angle" meaning that, unlike other beam attacks, it cannot be trivially neutralized by having reflection). If you still manage to survive, the deity will exclaim in shock "I believe it not!"
    • And if you're being digested by a monster at the time, then the lightning will hit the monster you're inside of, almost certainly killing it instead of you. If the monster survives the bolt, it gets hit by the disintegration beam too (although the only monster in Vanilla that engulfs and resists lightning also resists disintegration). You even get experience and break any Pacifist conduct for doing so.
  • Bottomless Bladder: The PC isn't required to sleep and recovers from wounds without having to rest. In fact, the only source of restful sleep is delivered by an amulet of restful sleep, which can be used to heal, but is mostly just there as a hazard.
    • SLASH'EM has toilets, but their use isn't obvious at first. If you're Satiated and sit on one, you "take a dump" and lose some nutrition, along with being cured of sickness. It is extremely unlikely someone will use it, but it's there.
  • Bread, Eggs, Milk, Squick: When you see your Attributes at the end. "You were stealthy. You were fast. You are dead."
  • Breakable Weapons: You cannot break melee weapons through fighting with them (though you have a small chance of shattering your opponents' weapons, depending on your skill and what each of you is wielding), but using bladed weapons to force locks can break them. Missile weapons have a chance of being "lost" (i.e., disappearing from the game) when they are used.
  • Breaking the Fourth Wall: Applying a stethoscope to listen to the very bottom of the screen gives, "You hear a faint typing noise."
  • Bucket Helmet: A rare variant on standard metal helmets, prized for being slightly lighter than its equivalents.
  • Butt-Dialing Mordor: The Big Bad Wizard of Yendor lives in an isolated tower in the middle of a dungeon level, which can normally only be reached by going down through the outskirts of that level, to a lower level which contains a magic portal to the tower. If you have a telepathic pet, the pet may helpfully wake the Wizard with a ranged psychic attack when you first cross his level, which can draw him out before you're ready to fight him.
  • Cannibalism Super Power: The standard means of acquiring elemental resistances, poison immunity, teleportation, etc. is to eat the corpses of monsters that have these abilities.
  • Cap: Several things are capped in NetHack.
    • The player's ability scores are capped at 25 (after all bonuses are applied). "Strength" behaves rather strangely, being semi-capped somewhere between 18 and 21—represented by 18/[number], where 0.[number] is the amount of extra strength above 18 you have. Just to be extra-confusing, 18/** strength counts as 21 for most purposes. The only way to boost Strength to 25 is to wear Gauntlets of Power.
    • The highest possible Luck score is 13.
    • The player's experience level is capped at 30.
    • Monster hit dice (for "normal" monsters) are capped at 49.
    • There are quite a few things that aren't directly capped, allowing them to go as high as [[Powers of Two Minus One (2⁸-1), (2¹⁶-1), (2³
-1), or possibly even (2⁶⁴-1)]] depending on the size of the variable they're stored in.
  • Candlelit Ritual: You need the Bell of Opening, The Book of the Dead, the Candelabrum of Invocation and seven beeswax or tallow candles to perform the rite that will grant access to the deepest dungeon levels where the Amulet of Yendor is. It's a sign of something that in older versions of NH scrounging up the needed number of candles sometimes proved to be almost as difficult as acquiring the rest of the items, to the point they were a fairly common use of a Wish. (3.6.0 has added a guaranteed source.)
  • Cast from Calories: Using spells makes you hungry. If you're a Wizard, having a high Intelligence stat reduces how hungry it makes you, and having a high enough intelligence can even negate the effect.
  • Challenge Run: invoked There's a bevy of conducts, i.e. voluntary challenges, including a Pacifist Run, an "atheist" run (not using the "pray" command to ask favors from the gods, or dropping anything on altars to test for alignment, or chatting with priests, or...), an "illiterate" run (not reading anything, and not writing anything beyond the letter X), a "foodless" run (not eating anything, including non-foods), and for the truly psychotic, combinations of any or all of the above resulting in things like "wishless genocideless polyitemless polyselfless illiterate atheist weaponless vegan" (actually achieved). You get nothing for completing these other than satisfaction, but the game will keep track of what you've accomplished. Nethack is already Nintendo Hard of itself, so these challenges add replay value only for the truly hardcore. The config file also lets you make your character blind. This makes the game extraordinarily difficult for obvious reasons and also because, as a traditional roguelike, Nethack involves a lot of painstaking item-identification, and being permanently blindfolded makes this nearly impossible (you generally can't read scrolls, see what potions look like, etc.).
  • Cherry Tapping: Almost any item can be used as a (probably very weak) weapon.
  • Chest Monster: Mimics lurking in stores are common killers of low-level characters.
  • Clothing Damage: Corrosive attacks can burn, rust, rot, and corrode your equipment, and under some circumstances it can be destroyed, for example, being struck by a Force Bolt or wand of Striking when wearing something made of crystal could cause it to shatter. Fooproofing your gear prevents this. Being forced to polymorph into a bigger creature will destroy your clothing too.
  • Color-Coded for Your Convenience: Unicorns are color-coded by alignment: black = chaotic, grey = neutral, white = lawful. Many other monsters, particularly dragons, are coded by properties: monsters with fire attacks (pyrolisks, hell hounds, red dragons) are usually red, monsters with cold attacks (blue jellies, winter wolves, white dragons) are usually blue or white, etc.
  • Color-Coded Stones: The game plays this one dead straight, with a few exceptions — there's two possibilities each for turquoise and aquamarine (green or blue), and fluorite is randomly assigned either green, blue, white or violet. All gems are just "<color> gem" until identified, so an unidentified "red gem" can't turn out to be sapphire, which is a blue gemnote .
  • Commonplace Rare:
    • Cans of grease are as handy as they are mundane, and they're also disgustingly uncommon. Grease is mostly valuable because it is rare — its effects are important but mostly supersedable (armor can be made permanently damageproof and there's a cloak and a bag that are effectively permanently greased. You'll still have to avoid melee with mind flayers). By the time you actually track down a can of grease, you're likely past the point in the game where it's valuable.
    • Another inexplicably uncommon item: shirts. T-shirts and Hawaiian shirts have no armor value in and of themselves, but can be enchanted to give a valuable extra few points of protection and worn under standard issue shining armor. If you can find one. One of the few advantages of the Tourist class is that you start out wearing the aforementioned Hawaiian shirt. For all other classes, wishing or polymorphing may be necessary.
  • Convection, Schmonvection: You can stand next to lava with no ill effects but if you try even flying over it without fire resistance you're in for a world of pain. Water Walking boots will let you walk over lava, but if they aren't fireproof themselves the lava will destroy them, then you fall in and die as a result.
  • Crazy-Prepared: The player, if they intend on being successful.
  • Critical Existence Failure: Down to one HP? Go ahead and kick a wall. I dare you.
  • Cthulhu Mythos: Some variants such as UnNetHack include some of these characters; in these Cthulhu himself guards the Amulet, and, unsurprisingly, is incredibly lethal even by NH standards.
  • Dangerous Forbidden Technique: In the form of risky strategies to win and/or kill monsters.
    • Wielding a "rubber chicken" (cockatrice corpse) allows you to insta-petrify almost any enemy—even high-level demon lords. But as you might imagine, it's extremely easy to petrify yourself with it by mistake. The biggest danger is falling—down the stairs, into a pit trap, etc.—while wielding the corpse. This can mostly be avoided by wearing a ring of levitation whenever the corpse is equipped, but you have to watch out for sinks.
    • The "digging for victory" strategy, where you get a pickaxe and some wands of digging and attempt to burrow straight down to the castle. From there, you can exploit the stupidity of the castle's inhabitants to kill most of them with the drawbridge, and get a wand of wishing as a Disc-One Nuke. Most of the time, though, this tactic will just get you killed by an enemy that's way out of your league.
    • The "protection racket," an opening strategy where you dive to Minetown as quickly as you can while your level is low, while gathering enough gold to buy divine protection from the priest through donations. This is risky in that trying to dive that far without killing any monsters has a huge chance of getting you killed, and there might not even be a priest in Minetown when you arrive, but again, it's a strong opening if you pull it off.note 
  • Damage Discrimination: Monsters have no friendly fire protection; if you're facing a mob of enemies, anyone between your character and a missile-user (up to and including dragons) stands a chance of getting hit. Also, if you wear a ring of conflict, any nearby creatures will start attacking each other.
  • Deader than Dead: The Auto-Revive up there? It doesn't work if you genocide your own race or class, or get your brain eaten. Well, technically it does, but you just die again.
  • Death by Gluttony: If you eat while satiated you can choke to death.
  • Deus Sex Machina: With proper preparation (or, as many like to say, "protection"), seducing succubi and incubi can permanently raise your level or stats and is generally a great resource. Specifically, whether the result of sex is good or bad depends on your Intelligence and Charisma.
  • Developer's Foresight: The former Trope Namer. It even has its own page. See here for aversions.
  • Diagonal Speed Boost: Naturally, as it's a Roguelike. The "grid bug conduct" challenge is for your player to ignore the diagonal speed boost, which makes the game a lot harder.
  • Disc-One Nuke: In a few ways, be it an early wish or polymorphing.
    • Some players regard "Elbereth" as a disk one nuke. Writing Elbereth in the dust with their fingers will protect the player from almost all early monsters, and many later ones. Magicbane takes this up to 11 because it always engraves successfully, in only one action, without using any charges. (In addition to protecting against some traps and hostile spells.) Wizards can get it very easily, but already start the game magic protected.
    • Throwing daggers, especially for Rogues. Due to class special abilities, a Rogue on the very first turn can throw up to 2 daggers at a time. Developing the skill can increase that to up to 4 daggers at a time. Enchanting the daggers (or finding enchanted daggers), plus strength damage bonus, means a Rogue is almost guaranteed to be a long range killer by machine-gunning daggers. This is why Rogues start with a stack of daggers. The drawback is the Rogue Quest, which should make any Rogue a part time alchemist. Some of the other classes can do the same, but have to find the daggers on their own, as well as develop the skill from scratch. Other than the Ranger they don't get the bonus toss and none of them can get a backstab bonus four times with one attack from nine squares away.
    • Excalibur is a very powerful weapon that can be acquired as early as level 5, and without much effort (be Lawful, find a longsword, and dip it into a fountain a few times). This is especially easy to pull off if you're a Knight or a Valkyrie, both of which start the game with a longsword.
    • It's entirely possible to stumble upon a Scroll of Genocide or a Wand of Death very early in the game; the former is almost a literal example, letting you erase entire classes of monsters from existence. Although, the most likely way to find the latter in the first few levels is in the hands of a gnome. Rarer super-items like artifacts can theoretically appear near the top of the dungeon, but you have a much better chance of lucking into a genie in a lamp, who can give you an artifact or other overpowered item if he's in the mood for it; Izchak's lighting shop, about 10 levels from the surface, often has a magic lamp.
  • Divine Punishment: Praying to your god when he is displeased with you, and too frequently, will first strike you by lighting, and if that doesn't work, a wide angle disintegration beam.
  • Do Not Drop Your Weapon: You can un-equip enemies with a bullwhip, ala Indiana Jones. One of the few useful applications for a bullwhip, since it is a pretty lousy weapon. Enemies can do the same, so if Magicbane is your only source of magic resistance, stay alert...
    • The player can drop their weapon if they eat greasy food without gloves on and don't use a towel to wipe off the grease, leading to Yet Another Stupid Death.
  • Downer Ending: Since NetHack 3.6.0, it is possible to offer the Amulet of Yendor to Moloch (using an altar in Moloch's Sanctum). As a result, he triumphs over your god and kills you for your trouble.
  • Dual Wielding: Blessed +7 Grayswandir and a blessed +7 silver saber, yeah baby!
  • Dungeon Bypass: Pick-axes can be used to tunnel around enemies and to dig a hole through the floor of one dungeon level down to the next, letting you bypass entire levels at a time (although you will have to deal with the bypassed levels on the way back up—unless you've got another cunning plan).
  • Dungeon Shop: An important source of items, and (possibly even more importantly) clues as to what the items are (since their appearance is randomized for each game and use-testing can be a very Bad Idea).
  • Easy-Mode Mockery: Playing in Exploration Mode locks you out of the high scores.
  • Easter Egg: Too many to list. Try doing something strange: the game gives an appropriate response instead of simply giving a generic you-can't-do-this response.
  • Eating the Enemy: One way to neutralize a troll's Healing Factor is for you or your pet to eat the corpse before the troll regenerates from it.
  • Elemental Embodiment: Some show up as normal enemies; they can also be summoned, much to the chagrin of anyone messing around with sinks or fountains.
  • Elemental Plane: The late game consists of making your way through the four Elemental Planes (Earth, Air, Fire, and Water) in order to reach the Astral Plane (which is where gods and angels reside). Each plane has a quirk to it that fits the theme of its element:
    • Earth is solid rock with caves scattered inside, with most of the enemies being creatures that can tunnel through stone. The player will need to dig through the walls in order to transverse this level.
    • Air is open air with massive clouds generating at random; while inside a cloud, there's a high chance of being hit by lightning and stunned, making you easy prey for monsters. Unless you can fly or levitate, you'll be tossed around at random by the wind.
    • Fire is a giant expanse of darkness and rivers of lava, which randomly spew toxic gas. There are tons of fire traps on the seemingly safe ground, and all monsters that generate are either resistant or immune to fire damage.
    • Water is completely underwater, with giant air bubbles that drift through it being the only safe zones for most players. The enemies for this level are water elementals and sea monsters, and the portal to the Astral Plane is in one of the other bubbles that drifts around the level; since it moves, this makes it one of the hardest portals to find.
  • Empathic Weapon: Intelligent artifacts, which will actively attack potential users that they don't like and can "evade your grasp" if you are both the wrong class and the wrong alignment.
    "You feel that the <item name> is ignoring you."
  • Everything's Better with Samurai: Not only can anyone get a katana, but a bunch of items are renamed in Japanese if you play the Samurai class.
  • Everything Trying to Kill You: And the SLASH'EM variant is even worse. And Slash'EM Extended even moreso.
  • Even Evil Has Standards: The Random Number God may occasionally give a gnome a Wand of Death, but at least it draws the line at letting monsters use Scrolls of Genocide.
    • Unless you're an orc or a caveman, cannibalism (or eating a dog or cat) gives you the aggravate monster intrinsic.
    • Even the Chaotic gods, who reward you for sacrificing members of your own race, will get angry with you (along with everything else in the dungeon) for eating the corpse of a dog or cat or offering a pet's corpse.
  • Evil-Detecting Dog:
    • Any non-undead pet has the innate ability to detect cursed items and will try its best never to step on them, or to do so only "reluctantly".
    • Also, when you put a leash on them they will whine or act nervous whenever there's a trap nearby, although normally they wouldn't notice.
  • Excuse Plot: Regardless of your character class (or alignment, or gender), the story is the same — fight and scheme your way to the bottom of this incredibly dangerous dungeon to retrieve the Amulet of Yendor for your god so you can become a demigod or demigoddess. The "quest" sub-plot is no better; they all boil down to "your friends don't like this guy/monster, go kill him/it." This doesn't matter, though, because the absurdly complex gameplay creates a story all its own (usually with a tragic ending).
  • Fair-Weather Mentor: The player, almost inevitably. You'll love your pet and give them easy kills and fresh corpses to help level them up, and they'll fight on your behalf... but when food starts getting scarce or you find yourself cornered by a level draining foe, it's every man for himself. There's no penalty for starving your pets to death or abandoning them when the going gets tough except the loss of the pet. Just don't Eat the Dog unless you really have to.
  • Felony Misdemeanor: The Minetown guards will attack and fight you to the death if you kick a tree or improvise with a bugle. Slaughtering all the non-shopkeeper residents does not provoke a similar reaction.
  • Foe-Tossing Charge: The game has many instances when the player is surrounded by monsters and only needs to pass through. In such situations, this trope can be imagined very easily. Especially if you have a wand of teleport. Especially if you have an extra one, so you can break it in two and teleport anything within range.
  • Flat-Earth Atheist: The "atheist" conduct involves not using any of the religious elements of the game (except for sacrificing the Amulet of Yendor, and even then, there's a patch to eliminate this, too), satisfying the technical specs of this trope. Of course, actually playing this way pretty much requires you to either know not to do these things, or die before you get to do them.
  • Forgot to Feed the Monster: While food (corpses) is very common and you usually don't have to actively feed your pets, it is possible for them to starve to death. Can also be reversed—when you're hungry, your pet might eat food before you can. Your pets will also go feral if you leave them on a different level for too long.
  • Fourth-Wall Mail Slot: On some Unix systems, if you receive a new email while playing, the email is brought to you on a scroll in-game, delivered by the mail daemon.
  • Gender Bender: Wear unidentified amulets or mess around with polymorphing at your own risk.
  • Genie in a Bottle: In magic lamps as well as (sometimes) actual bottles. Possible source of a wish, if handled correctly.
  • "Get Back Here!" Boss: Demon lords and the more powerful types of liches can teleport around at will, and will use this ability to run off and heal. Generally speaking, they always run off to the upstairs, meaning once they start that nonsense, you should be running that way, too.
  • Glass Cannon: The Wizard class starts out physically weak but with some powerful equipment and spells. Just don't let stuff get close enough to beat on you.
  • God Job: Your reward for Ascending.
  • Gone Horribly Right: With work, it's possible to genocide a whole range of creatures, the weaker ones. Overdo the blessed scrolls of genocide and all that's left are the very toughest creatures, which aren't genocide-able. The final stages of the game become even more exciting, and frequently, much shorter, too.
  • Gratuitous Japanese: Playing a Samurai, the game feedback will call certain items by the Japanese name (helmet -> kabuto) or a rough Japanese equivalent (booze -> sake), even though they're literally the same item behind the scenes. The samurai Quest is particularly full of this.
    • Not all of it is accurate Japanese, mind. "Shito" is probably just a misspelling of "shōtō"note , but no one seems to know what word the devs were going for with "gunyoki".
  • Grave Humor: Any grave that wasn't generated by a player's death randomly generates a humorous message. added a ton of them.
  • Grave Robbing: Allows you to find gold and items. Slightly less helpfully, lets you find mummies and zombies.
  • Grievous Harm with a Body: You can wield corpses as weapons, but the only major use for this is wielding a cockatrice corpse (with gloves on, of course) to create a petrifying club.
  • The Guards Must Be Crazy:
    • If you tell a vault guard your name is Croesus, he will assume you are the Croesus, his boss, and (if the real Croesus is still alive) will let you get back to stealing all his gold, even if you're the wrong gender and/or the wrong species to pass as Croesus. This is justified by the ability to change form and gender being present and common enough that the master of Fort Ludios would have it at his disposal. You can also deter the guard by being unable to speak (he leaves, saying "I'll be back when you're ready to speak to me!") or by eating a mimic corpse while hallucinating, which disguises you as an orange: "Hey! Who left that orange in here?".
    • The numerous soldiers and monsters in the Castle will make no attempt to stop you as you stand outside messing around with a bugle, obviously trying to guess the Song In The Key Of Lock that opens the drawbridge. Once you know the tune, you can play it to lower the bridge, play it again to raise the bridge and crush any mooks that were trying to cross, and repeat; they never catch on, and will continue marching to their doom until they've all been squashed.
  • Hailfire Peaks: The Valkyrie Quest has both lava and ice in the same map. Explained as the result of Fire Giants invading the naturally frosty Valkyrie homeland.
  • Have a Nice Death: Your tombstone tells you how you died; usually that just means which monster, but sometimes, it's much more unique. Figuring out just how to reproduce a specific death can be a non-trivial exercise in itself. ("turned to slime by a scroll of genocide", anyone?)
    • It's even possible to have 'elementary chemistry' as a cause of death, if you're careless with acid.
    • Tossing a dead cockatrice in the air and catching it on your head nets the epitaph "petrified by elementary physics". Tossing a heavy object in the same way will get you "killed by elementary physics" instead.
  • Hawaiian-Shirted Tourist: All Tourists start with a Hawaiian shirt, not to mention an expensive camera.
  • Healing Factor: Trolls usually revive themselves at full health shortly after death. There are a few ways to prevent this, including eating the corpse, though sometimes they revive mid-meal.
  • Helpful Mook: Nurses are the Genuinely Gentle kind. If you disrobe and sheathe your weapon, they'll heal you with their attacks. Succubi can be the Accidentally Assisting kind if you play your cards right.
  • Hit Points
  • Hoist by His Own Petard: The easiest way to kill Medusa is with a mirror of some kind. This includes any item that provides reflection. This works similarly on Floating Eyes; using a mirror on one makes it freeze from its own gaze.
    • Also applies to Croesus, who lives in Fort Ludios. Fort Ludios has two important choke points (the door out of the room you start in, and the door to the fort itself), presumably because they would help against a larger invading army. Unfortunately for him, he didn't count on lone adventurers using that choke point to kill off all his soldiers one by one.
    • And anyone (character or monster) using a beam-weapon wand runs the risk of getting hit with a ricochet-blast off the nearest wall.
  • Holiday Mode: Date, time, and phase of the moon may all affect the game.
    • On Friday the 13th, the start-up message says "Watch out! Bad things can happen on Friday the 13th", and your base luck is reduced.
    • On a full moon, the start-up message says, "You are lucky! Full moon tonight", and your base luck is increased, but dogs may be less friendly, and werecreatures are usually in animal form, especially at night.
    • During the new moon, cockatrices are more dangerous.
    • Between 10 pm and 6 am, some creatures are slightly more dangerous. Gremlins, for instance, gain a 1/10 chance of stealing one of your intrinsics like telepathy or an elemental resistance each time one hits you.
    • From midnight till 1 am, undead do twice as much damage, and you get a different message when entering graveyards.
  • Horsemen of the Apocalypse: Death, Pestilence, and Famine (referred to as The Riders) make an appearance as endbosses in the Astral Plane. War is the player.
  • Hollywood Chameleon: Chameleons in NetHack can disguise themselves as other creatures, and even gain the abilities of whatever they mimic.
  • I Fought the Law and the Law Won: The Keystone Kops will spawn in large numbers if you rob a store. They are among the only monsters in the game that can never be rendered permanently extinct. No matter how many armies of them you defeat, there'll always be another pack ready to jump you NEXT time you step outta line.
  • If You Die, I Call Your Stuff: Thanks to bones files, you may find the remains of previous, unlucky heroes (usually a corpse and a restless shade, but sometimes a statue or a slime), complete with their whole inventory. Fraught with some danger, though—each item has a random chance of being cursed.
  • Implacable Man: Once you're high level and well-tooled for melee with AC in the negatives and a ring of regeneration, you can smite an entire room of trolls and dragons, taking blows and regenerating the damage faster than they can dish it out. Then in walks a gnome who puts you to sleep with his wand and beats you to death with his tiny crossbow.
  • Improvised Weapon: Speaking of beating things to death, you can wield nearly any item and use it for the blunt-force trauma if nothing else.
  • Infinite Stock For Sale: Not only does each shop have a limited inventory, they also have a limited amount of money with which to buy items you want to sell.note 
  • Infinity +1 Sword: Grayswandir, a silver saber which deals double damage to all monsters (instead of just some like other artifacts), plus extra damage to silver-hating monsters.
    • Although there are other far more powerful attacks in the game. Especially ranged attacks that can kill enemies before they get close enough to hurt your character. See Storm Damage.
  • In-Game Banking Services: Shop owners will run out of money and offer store credit for further items you sell to them.
  • Instrument of Murder: The Frost Horn, the Fire Horn and the Earthquake Drum. Yes, they're Exactly What It Says on the Tin.
  • Interface Screw: the Rogue level, a Shout-Out to the interface of NetHack's predecessor.
    • The Rogue level is nothing compared to being confused, stunned, or most especially, hallucinating. When confused or stunned, moving takes you in the wrong direction most of the time. When hallucinating, every item and creature appears to be some other random thing (some of which aren't normally found in the game).
    • Blinded can sometimes be worse. Being blinded in a shop will guarantee you YASD. The same with Temples and Towns.
  • Inventory Management Puzzle: You can carry a lot of swag, but eventually, you have to start caching, and if you want to be 100% certain of not losing a cache, you either have to bury it or put it in a locked chest, on a scroll of scare monster, on a dungeon tile which has had "Elbereth" etched into it. And even then, there's probably some way it can go wrong...
  • Invisibility Cloak: Available as both a cloak and a ring, as well as intrinsic invisibility conferred by wand (permanent), and potion or spell (temporary). It doesn't make you completely unfindable; monsters will try to guess your location and attack where they think you are. All of the above items can also be used by monsters, making the "See Invisible" intrinsic very important.
  • Just Add Water: Several types:
    • Dragon scales (dropped by dragons) + Scroll of Enchant Armor = Dragon Scale Mail (one of the best armor choices)
    • Wielded Worm tooth + Scroll of Enchant Weapon = Crysknife (a Shout-Out to Dune).
    • Alchemy: mixing less-useful potions can generate more-useful potions (and vice versa).
    • Once you know a scroll or spellbook, you can write more copies with a magic marker on a blank scroll or spellbook. On the other hand, magic markers are hard to come by and often have to be wished for.
  • Karma Meter: Your alignment record, which, just like it sounds, is a record of how well you've been sticking to your invoked Character Alignment. What effects it, naturally enough, depends on what that alignment is. If the record is below zero, you can use a cross-aligned altar to change your alignment permanently, though doing this too early is a one-way ticket to Unwinnable by Design, since you can't ever change back.
  • Karmic Misfire: If you're engulfed by a monster and your god is pissed at you, you can pray and get your god to smite you. The lightning bolt will destroy the monster and leave you unharmed (though you had better have disintegration resistance to deal with your god's second attempt).
  • Katanas Are Just Better: They get +1 to hit for no particular reason. Downplayed, though, as they are far from the best available sword, only a slightly better variant of a plain longsword; and Lawful characters will still prefer the longsword for its ability to transform into Excalibur.
  • Ki Manipulation: The Monk gets these in SLASH'EM.
  • Kick the Dog: You can do this if you like, literally even. You Bastard!. Seeing as your pet is your loving sidekick and in fact one of your more useful assets, this is usually an accident when it happens. On occasion, you do have to go so far as to Shoot the Dog if it turns on you. Offering your pet on an altar gets your patron god angry at you, by the way. And if you eat the corpse of a dog or a cat, everything in the dungeon will be aggravated at you... well, even more so.
  • The Last Straw: If you're satiated, then eating anything—even an insubstantial wraith corpse—has a chance of causing you to choke to death... and that wraith corpse doesn't give the player a warning beforehand. Amulets of Magical Breathing prevent this, at least.
  • Kitchen Sink Included: With a surprisingly large number of gameplay uses.
  • Leeroy Jenkins: Attacking everything in sight is a good way to get killed at lower levels. The Guidebook specifically discourages this kind of behavior.
  • Lethal Joke Character: Tourists have a hard time early on, but if they survive long enough, they get the ludicrously useful Platinum Yendorian Express Card (which acts as a self-regenerating scroll of charging, letting you reuse wands and tools with impunity) and can beat the rest of the game relatively easily.
  • Lethal Joke Item: Quite a few examples. T-Shirts seem silly and useless, but they fill a unique equip slot and can be enchanted to provide several free armor points. Expensive Cameras blind and scare monsters—including some very high-level ones that are hard to fight by other means. Appropriately, the Tourist starts the game with both of the above (and not much else). Even Wands of Nothing (which do nothing) are useful because they can be reliably polymorphed into much better wands.
  • Level Grinding: Before version 3.6, the "pudding farming" method allowed you to collect massive amounts of hit points—as well as really good loot.
    • Also contains Anti-Grinding—leveling up too much before you find good equipment is a good way to get yourself into trouble.
  • Level Scaling: Bases the level of enemies you'll face on the average of your character level, and the depth you've reached in the dungeon.
  • Location Theme Naming: Shopkeepers are named after real-world towns from various countries, depending on the type of shop: Russian towns for potion shops, Irish towns for scroll/spellbook shops, Turkish towns for armor shops, Welsh towns for wand shops, Nordic towns for ring shops, Indonesian towns for food shops, French towns for weapon shops, and Surinamese towns for general stores.
  • Logical Weakness: Tridents have a to-hit bonus against aquatic monsters. Axes do extra damage to Wood Golems. Clay Golems can be destroyed in one shot by erasing the runes on their foreheads.
  • Loophole Abuse: You can't teleport to another level while carrying the Amulet of Yendor (if you could, escaping the dungeon would be far too easy). But you can use a cursed potion of gain level to float up through the ceiling to the level above you, because, technically, that isn't teleporting.
  • Lord British Postulate: The Riders in the Astral Plane can be killed, but revive themselves in short order; they're supposed to harass you into ascending (or dying) instead of hanging around on the final level indefinitely. You can't get rid of their corpses in any of the usual ways—eating them is fatal, trying to shove them in a tin can makes them revive instantly, etc. But there are a few bizarre ways to kill them permanently, such as filling every square on the level with monsters so they have nowhere to spawn (giving the message "You feel less hassled;" once their corpses rot away they will be gone for good).
  • Luck-Based Mission: Luck plays an important role in NetHack; if the Random Number God wants to kill you, it probably will, because, at any given moment, there are many things that can go wrong. Taking precautions that will let you survive its wrath is an important part of the game.
    • Christian Bressler, aka 'Marvin the Paranoid Android' Ascended 23 times in a row over a three month span on the public server NAO, mostly to show that any individual game could be won. Including one of every class for the first 13, then he started doing conducts.
    • Adeon, another NAO player, Ascended 29 times in a row over the course of just barely more than one month.
    • Those records have since been bested on NAO (though in version 3.6.6 rather than 3.4.3) by Tariru, who won 61 times in a row.
    • ais523 did prove that it's theoretically possible to die before you have control of your character, the very definition of an unavoidable death. Grayswandir was generated on the upstairs, he picked it up due to autopickup, and it blasted him. He did some calculations and estimated a 1 in 3 million chance (roughly) of this occurring.
    • One of the various traps that an adventurer can encounter is a pit. Sometimes, this pit has spikes. Sometimes, these spikes are poisoned. And sometimes, poison is instantly lethal. Therefore, characters who don't possess poison resistance could theoretically die at any given moment, should they wander into a trap such as this.
      • The truly paranoid will try to only step where they've seen other monsters step safely, or search when that's not possible.
  • MacGuffin: The Amulet of Yendor.
  • MacGuffin Delivery Service: A viable strategy for obtaining the Amulet of Yendor. Allowing a covetous monster, such as Yeenoghu or Juiblex, to steal the Amulet of Yendor for you, may be easier than fighting through Moloch's Sanctum.
  • Macrogame: Bones files — a good argument for playing on an online server.
  • Magikarp Power: The tourist character class. All the "weak" character classes have this to some extent — but it's most noticeable with the tourist, who might be the easiest role to win with if you survive past the Quest. But that's a big "if." The Tourist starts with a stack of throwing darts, a flashy camera, some money, a pile of food, two healing potions, and some scrolls that are useful only in the endgame. They do not start with any melee (or non-expendable) weapon, any spells, any armor, or decent combat stats in case they comes across either of the above, and shops will vastly overcharge them for the first half of the game. The throwing darts they do have are a ranged weapon, and can be upgraded with a poison, but they aren't very useful compared to other class' weapons. If a tourist survives to the quest, though, their reward is effectively an infinite-use blessed scroll of charging (which also grants magic resistance, super-telepathy, and half damage from enemy magic just by having it in your inventory), which means double or triple the duration of most wands, easy creation of +4 or +5 rings, and infinite uses of most tools (including a food generator, an enemy tamer, and some that mimic offensive wands). And to top it off, your useless starting shirt and scrolls become valuable in the endgame, and the stats that start the highest are the hardest ones to increase later on.
  • Magic Pants:
    • The game tracks the characters' size: if you change into a much larger form, then the armor you're wearing will be torn apart and destroyed. And if you turn into something exceptionally weak and puny, you'll be half-squashed by the same armor and unable to move.
    • Implied with the player's actual pants — while there are no equippable pants in NetHack, if you sit on a cockatrice corpse, you don't turn to stone, so you must be wearing pants. Since they don't tear apart or anything, they must be magic.
  • Magic Potion: The hero can use and make potions. Most of them bring good effects, although some of them are utterly harmful.
  • Make a Wish: The most certain, and in some cases only, way of getting some desirable rare items. On the other hand, it may be much more useful to wish for an item with an important Mundane Utility.
  • The Many Deaths of You: There are many (many many) ways to die, leading to a lot of Trial-and-Error Gameplay. Some can only realistically be obtained by deliberately setting out to collect them.
    • An incomplete list for Nethack 3.3.1 can be found here.
    • keeps track of all deaths that occur on the server. Even ignoring unique deaths caused by monsters with custom names, the number of unique deaths range in the thousands.
  • Medusa: A boss, though by the time you reach her you're usually strong enough that she's no big deal. Getting to her is often more challenging than actually defeating her, since she has a unique level that requires the player to cross large bodies of water to reach her on her island, and the water is infested with sea monsters that can drag you in and drown you.
  • Mega Dungeon: The game is set in the Mazes of Menace, comprising around 50 levels, which your intrepid adventurer (or tourist, or caveman) enters to recover the Amulet of Yendor from beyond the Valley of Gehennom and offer it to the gods.
  • Mini-Game:
    • The Sokoban branch. Interestingly, the Mini-Game is done with the same mechanics as the rest of the game, with only minimal changes (boulders can't be pushed diagonally, and you can't fly over holes in the floor).
      • And certain other things (i.e. using spells to get rid of boulders) will give you a luck penalty.
    • One way to enter the Castle is by winning a game of Mastermind.
    • In the endgame, wielding the Amulet of Yendor lets you play hot/cold to find the hidden portals to the next level.
    • "Mother, May I?" with the Quest Leader.
    • Minesweeper in the Ft. Ludios treasure room. (Although this may be more of a Shout-Out.)
  • Metagame: Many sort-of-intentional deaths are caused on the first few levels by people repeatedly seeking some early advantage, such as quaffing from fountains (it's supplication to the Random Number God for a wish, in case you're curious), or kicking sinks for a ring and then dying if a foocubus/black pudding comes up and they can't handle it (or don't want to waste time handling it). This is a form of startscumming, and not everyone thinks it's a-OK.
  • Mighty Glacier: Mûmakil. Their cousins baluchitheria, as well, to a degree, but those are slightly faster and, although tougher, less offensively strong.
  • Mini-Dungeon: The game has a few side branches, such as the gnome mines and a couple of towers.
  • Mission from God: The Excuse Plot.
  • Money for Nothing: There are things that are worth spending gold on, but the fact that you can kill almost anything you gave your gold to means that generally, once you're done with getting your protection, you're more or less done with money as well.
  • Monsters Everywhere: Horses, bees, trolls, elves, snakes, demons—and everything in between—grows out of rock. Or perhaps they are spawned by the evil Wizard. But why then does he spawn a puny rat to defeat the hero that just killed five dragons without breaking a sweat? Maybe to maintain a certain ambiance? Kitten and Vampire Lord fights side by side!
  • Mook Bouncer: The Quantum Mechanic has a "teleport" attack.
  • Munchkin: Not playing this way is practically suicide.
  • Mundane Utility: Magic lamps contain djinn, a.k.a. genies. Many players will delay or forego releasing the genie because keeping it trapped in the lamp makes it produce light indefinitely, without needing to refuel with oil like a non-magic lamp. Oil can be hard to come by, and many sections of the dungeon, especially the Gnomish Mines, are pitch-dark.
  • Mushroom Samba: The hallucination effect. It's a temporary status effect obtained by drinking a certain type of potion, eating the corpses of some monsters (including several fungus monsters), or being hit by an exploding black light. It causes nearby monsters and items to appear as random other items or monsters that don't actually exist. It also gives alternate messages for most visual and audio messages.
  • Needle in a Stack of Needles: One of the things the Wizard can do to make your life more difficult is steal the Amulet of Yendor. And then leave fake ones. Do not try to enter the endgame without the real one...
    • Quaffing a cursed Potion of Gain Level on dungeon level 1 is a failsafe way to exit the Dungeons of Doom. If the player's not carrying the Amulet of Yendor, he/she just "feels uneasy." If he does have the amulet, it's up and out. The Dev Team Really Does think of everything.
  • Nerf: Version 3.6.0 makes Elbereth significantly less permanent - even burned-in engravings of 'Elbereth' have a chance to fade when they turn monsters away, and the word itself requires you to stand upon it to activate, meaning that you cannot simply burn-in the word to protect a space for your stash or deny entry of monsters.
  • Nerf Arm: Cream pies are surprisingly useful as weapons, and you can eat them.
  • Nintendo Hard: To the point where there is no shame in dying on the second or third level if you're a new player. One can die in less than 50 turns if they don't know what they're doing, and it's not unheard of for players to die on their first turn (but you have to try fairly hard, or be really unlucky, to do that).
  • No Can Opener: The game has edible "tins" and with a tinning kit you can even make your own canned food from monster corpses. Opening them can be tricky. If you're wielding a tin opener, dagger, or axe, or if the tin is "blessed," it pops right open. If not, you spend a lot of turns—during which monsters may sneak up on you, or you might pass out from hunger—desperately trying to squeeze it open, and if you're insufficiently strong/dexterous, the can will probably remain sealed.
  • No Fair Cheating: If the game detects that the save was manipulated, it will immediately kill the player, amulets of life-saving be damned, and will say the player died to "a trickery".
  • Non-Health Damage: Mind Flayers, drain intelligence by eating a target's brains, which takes their intelligence to 0 and kills them by the Stat Death of "brainlessness", and not even an Amulet of Life Saving will save you, you are Deader than Dead.
  • Non-Human Undead: Zombie and mummy giants, elves, dwarves, orcs, and gnomes along with the regular ol' human variant. You can also zap most corpses with wands of undead turning to bring monsters and animals back to life.
  • Nostalgia Level: The Rogue level, a reference to the original Rogue, is presented in black and white, with different symbols for various features and objects, and even some changes to game mechanics (such as monsters not leaving corpses).
  • The Nudifier: The scroll of destroy armor (and the destroy armor spell used by certain monsters).
  • Offerings to the Gods: You can sacrifice the fresh corpses of monsters you've slain at an altar of your own alignment and gain luck. Sacrifice enough and you can even gain an artifact.
  • Olympus Mons: A high-ranking angelic being and an uber-powerful undead mage can both be your pets, despite possibly being powerful enough to destroy your character several times over. With a bit of work, even two of the horsemen of the apocalypse can be brought under your control.
  • One-Hit Kill: Tons of em, on both sides.
    • To name a few: A Wand of Death, the Finger of Death spell, a bad roll on a poison check, doing anything that involves your bare skin and anything even tangentially related to a footrice including the contents of their eggs, hitting a Floating Eye in some cases, encountering a soldier ant/leocrotta/mûmak/minotaur when unprepared for melee, Medusa's gaze. A drowning attack is technically a two-hit kill but feels like a one-hit kill.
    • Two artifact weapons, the Vorpal Blade and the Tsurugi of Muramasa, have a 5% chance to inflict instant death, which is completely irresistable to anything humanoid (and the majority of things that aren't). The Tsurugi is guaranteed to spawn in the hands of one class's quest nemeses (giving this boss the 5% chance to instantly kill you), and the Vorpal Blade can randomly be given to monsters on the very last level of the game.
  • Optional Sexual Encounter: Succubi and incubi again. The former page image for that trope was from this game.
  • Our Werebeasts Are Different: Werewolves, wererats, and werejackals.
  • Pacifist Run: invoked It is possible for a very skilled player to win the game without personally killing anything. The game will even acknowledge it.
  • Pet Interface: A surprising amount for tame monsters.
    • The safe_pet and highlight pet options.
    • Carrying pet treats in open inventory (tripe for dogs/cats, pears/apples for horses) means your pet will stay much closer to you.
      • Tossing your pet a treat reinforces its recent behavior. You can train your pet to steal from shops!
    • A leash physically keeps your pet close to you, even when going up/down stairs or dropping through holes. (You can use multiple leashes, too.)
    • A tin whistle will kind of call your pet to you. A magic whistle will teleport your pet(s) to your side if they're anywhere on the level.
    • #chatting to your pet can tell you about their condition.
    • Pets are reluctant to step on a square with a cursed item on it (unless there's food there they want.) This can identify cursed items. It can also be used to control a tame animal's movement.
    • You can 'a'pply a bullwhip at a humanoid pet to take their weapon away. (For replacement with a better weapon.) You can also prepare and leave weapons, armor, and tools for your humanoid pets to pick up and use.
    • Wand of probing tells what a monster (tame or otherwise) is carrying.
    • A stethoscope tells an animal's basic Hit Points and its speed.
    • Spells of healing and extra healing can be used to heal pets.
    • Breaking a potion of regular, extra, or full healing can heal pets.
    • Saddles permit horses, dragons, and some other monsters to be ridden.
  • Player Data Sharing: Bones files allow the corpses/graves of previous player characters to show up.
  • Point of No Return: Right before the elemental planes.
  • Poirot Speak: For the Samurai role some item names are translated into Japanese, and the quest dialogue is lightly peppered with miscellaneous Japanese words and expressions.
  • Police Are Useless:
    • Exaggerated with the Minetown Watch, who will summarily execute anybody who breaks down a door, clogs up a fountain, cuts down a tree or so much as touches a shopkeeper, yet do absolutely nothing about the many often-strong hostile monsters found on the level, which can spell an inescapable death for a low-level player. The Watch will also completely ignore the murder of peaceful animals and humanoids in their town.
    • Played for Laughs with the Keystone Kops, which can appear on any level if you manage to liberate unpaid items from a shop. Their preferred weapons are rubber hose whips and thrown cream pies, and unlike the Minetown Watchmen, they are low-level and easy to defeat.
  • Potion-Brewing Mechanic:
    • Potions can be mixed together to create new potions. For example, a potion of healing and a potion of gain energy make a potion of extra healing.
    • The variant UnNethack changes this in an interesting way. As is common in the roguelike genre, Nethack's object descriptions are randomised, so a healing potion might be "a red potion" in one game and "a green potion" in another. In UnNethack, alchemy is based on color instead of effect, so that, for example, a red potion (whatever that is) and a yellow potion (whatever that is) always make an orange potion (whatever that is) - effectively randomising the alchemy recipes.
    • There's another patch that allows you to create potions by dissolving gems in acid.
  • Press Start to Game Over: If you're very unlucky with the Randomly Generated Levels, it's possible to die on your first turn, and there's even a special Have a Nice Death message for it.
    Do not pass Go. Do not collect 200 zorkmids.
  • Primitive Clubs: The Caveman role starts with high strength, low intelligence and primitive weapons such as rocks and a club.
  • Permadeath: All deaths are final, unless you have a certain rare item...
  • Press X to Die:
    • Among many, many other ways to die, the game allows you to teleport to a negative level; and immediately fall thousands of feet to your death. Unless you can fly. (Your game still ends, though.) If you go to level -10 or above, you go to Heaven instead. Though it won't save you from death by teleporting to level 0:
    Nethack: Go to Nowhere. Are you sure? [ynq] (q) y
    Nethack: You scream in agony as your body begins to warp...—More—
    Nethack: You cease to exist.—More—
    Nethack: Your possessions land on the floor with a thud.—More—
    Nethack: Do you want your possessions identified? [ynq] (n)
    Score List: Player, committed suicide.
    • Throwing rocks at the ceiling and taking damage when they hit you on the head.
    • Hurting your leg when you kick something immobile.
    • Falling down staircases because you're carrying too much.
      • Getting stoned because you tried to go down stairs while wielding a cockatrice corpse and carrying too much.
    • Choking by trying to eat a boulder made of meat.
    • Shooting yourself with a wand of death. There's a reason the game coined the term Yet Another Stupid Death.
    • There are no less than forty-five ways to get yourself killed by a cockatrice - and only a few are from enemies.
    • It's even possible to attempt to mount your horse, slip off, and kill yourself... on the very first turn!
    Nethack: "Do not pass go. Do not collect 200 zorkmids."
  • Psychic Radar: Telepaths can, when blinded in any manner, see the exact location of any monster on the current floor that can think.
  • Public Domain Artifact: Several of the one-of-a-kind artifacts, including Excalibur, Mjollnir, and the tsurugi of Muramasa.
  • Pun:
    • Levitating characters will sink if they float over a sink.
    • Drinking a cursed potion of gain level causes a character to move up a dungeon level.
    • Scrolls of mail, on UNIX systems, are delivered by a mail daemon.
    • If you try to identify a wand of striking by engraving something on the floor, you'll receive a message that it "unsuccessfully fights your attempt to write."
    • The tourist's artifact, a credit card, lets you charge items.
  • Pun-Based Creature: Fire ants can set the character on fire.
  • Random Number God: The Trope Namer.
    • Randomly Generated Loot: He holds domain over the loot, like any good roguelike's RNG. Some items get blessed or cursed, a few items get fireproof or rustproof, and a few items get a numeric bonus, like a stack of +1 darts.
  • Random Loot Exchanger: The lets players use wands of polymorph on piles of loot on the ground. If you're lucky, it will turn it into other loot of a similar category (weapon, armor, food, scrolls, wands). If you're unlucky, the junk will fuse into a hostile Golem instead.
  • Rare Candy: Potions of gain level and wraith corpses give level-ups. Potions of gain ability (especially blessed) and the "gain ability" effect of magic fountains increase stats.
  • Ret-Gone: A scroll of genocide not only kills all monsters of a given type, it removes them from reality. If you genocide cockatrice and you were holding a cockatrice in your hand and three of their eggs in your backpack, they'll all vanish. If you had a tin filled with red dragon meat and you genocide red dragons, that tin mysteriously becomes empty. And you'll find yourself unable to polymorph into one now, even if you had already done so before. Also, if you genocide your own race/role while polymorphed, the game will say "you feel empty inside". Try to turn back and you will die. If you quit before dying, the game will read "quit while already on Charon's boat."
  • Required Secondary Powers: Scrolls of fire and books of fireball can't burn, Wands and books of cancellation can't be canceled, wands, potions, and books of polymorph can't be polymorphed. The idea being that immunity to the effect they contain is necessary to contain it in the first place.
  • Revive Kills Zombie: Pestilence (one of the Horsemen of the Apocalypse) takes severe damage if you throw healing potions at him (However, his magic resistance is so high that he will always resist this effect unless you level-drain him first). Inverted for Death, who is healed by instadeath spells.
  • Rodents of Unusual Size: The game features Giant Rats as a low-level pest.
  • Rule of Three: There are three end game bosses to fight.
  • Save-Game Limits: The game only allows one savefile per character. If you want to make backups to protect against crashes, you'll have to do that manually. Any other use of backups is considered very bad form.
  • Save Scumming: Like just about any roguelike, NetHack erases your save upon death. Instead, some players will "start scum," repeatedly starting and quitting the game until one gets a favorable set of starting equipment or stats. This is usually done with wizards, due to the ridiculous magical items a lucky wizard can start the game with (pre-ID'd to boot). A little over 50% of all NAO games are turn-0 quits, a good portion of those wizards.
  • Schizophrenic Difficulty: Despite dangers like arch-liches, mind flayers, and Rodney chasing you, the game gets much, much easier after the first dozen levels or so due to the necessity of being Crazy-Prepared and to vastly overpowered early monsters like soldier ants, leocrottas, and chameleons.
  • Schmuck Bait: Most unidentified scrolls have gibberish names like "ZELGO MER" or "XIXAXA XOXAXA XUXAXA," but one of them is titled "READ ME." Are you feeling lucky?
  • Sealed Room in the Middle of Nowhere: Where you end up if you teleport by accident into a vault. Sure, there's a guard who comes along to check it, but if you refuse to give up all your gold or keep saying you're Croesus, or dig your way out, you're stuck inside until you starve to death.
  • Semantic Superpower: Several magical items in the game derive their power from puns:
    • A Potion of Gain Level normally increases your Character Level, but will increase dungeon level if cursed.
    • "Turn undead" effects can be used to Animate Dead.
    • An artifact credit card can be used to charge items.
  • Shape Dies, Shifter Survives: Running out of HP while polymorphed will force you back into your natural form... unless you're wearing an amulet of unchanging, in which case you're stuck and you die. Dying any other way will also kill you for real.
  • Shapeshifter Mode Lock: This will happen if you genocide your race/role while polymorphed. Try to change back and you will die. Also, Amulets of Unchanging can be worn for this effect.
  • Shapeshifting Excludes Clothing: For the most part, unless it's magical Dragon Scale Mail.
  • Shoplift and Die: The trope was once named Izchak's Wrath, after the only non-random shopkeeper in NetHack.
  • Sidequest: the Gnomish Mines, Fort Ludios, and Sokoban can be skipped.
    • It might actually be impossible to visit Fort Ludios in a given game.
  • Silliness Switch: Hallucinations, caused by magic or dodgy food. Non-hallucinating silliness includes kitchen sinks, tourists, cameras, Hawaiian shirts, and even the Keystone Kops.
  • Silver Has Mystic Powers: Vampires, werewolves, and a few other enemies take bonus damage when hit by anything made of silver (even if it isn't a weapon). Shades can only be harmed by a short list of items, one of which is silver.
  • Skeleton Key: Any key found will unlock any door or chest (older versions had different kinds of keys that could only open corresponding types of locks).
  • Skeleton Key Card: The tourist's credit card.
  • Songs in the Key of Lock: One way of getting into the Castle. A (possibly unintended) side effect allows you to easily kill off most of the monsters in the castle: Playing the pass-tune again closes the drawbridge, and any monster on the drawbridge will be crushed to death when it closes. Wash, rinse, repeat. This also destroys any loot they're carrying, though.
  • Spikes of Doom: You fall into a pit! You land on a set of sharp iron spikes! The spikes were poisoned! The poison was deadly...
  • Spoonerism: The function responsible for Turn Undead animating corpses is called unturn_dead().
  • Squishy Wizard: Played straight with the Wizard class, but you can beef yourself up with some careful Elite Tweaking.
  • Stat Death: If your Intelligence stat drops below 3 (usually by mind flayer attack, although there are other ways to do this), you "die of brainlessness".
  • Stealth Pun: A very stealthy one is the reason why demons are represented by the "&" character: It refers to the concept of a "daemon" in POSIX operating systems, which is a program that runs in the background. When launching a program from a command line, you can specify that it shall run in the background by appending a "&" to the command.
  • Stock Animal Diet: Horses eat apples and carrots. Thus, a Knight starts the game with apples and carrots, to feed its pet pony. Horses can also eat other vegetarian food, such as lichen corpses.
  • Stuck Items: Cursed armor can't be removed, and cursed weapons can't be un-wielded. There are several ways of dealing with these problems, only one ("remove curse") obvious.note 
  • Stupidity-Inducing Attack: Mind Flayers have an attack that reduces intelligence.
  • Suffer the Slings: An available weapon; although not particularly effective, at least the ammunition is easy to come by.
  • Superboss: Demogorgon is the strongest monster in the game, but you might not encounter him, since he can only be summoned by another demon prince. Even if you do, you might be able to run away, in which case you probably should.
  • Super Drowning Skills: You cannot swim, at all, unless you're polymorphed into an aquatic creature. Stepping into water is very hazardous—you always "sink like a rock" and if you're too encumbered to climb out quickly, you'll die instantly. Some monsters can grab you and drag you into water, which is also immediately fatal.
    • Wearing an amulet of magical breathing makes you completely drownproof (technically it removes your need to breathe entirely, so you also can't choke and are unaffected by hazardous gasses). Even with that superpower, you still can't swim, but can cross water by walking along the bottom.
    • Thankfully, non-aquatic monsters also follow this trope, and aren't smart enough to climb out before they suffocate; dropping powerful ones into water (by melting ice underneath them, for example) can be a good way to eliminate them.
    • This applies in a strange way to inanimate objects—non-enchanted iron items that have any contact with water have a 50/50 chance of rusting/getting more rusty, giving weapons a debuff in the process. Scrolls and spellbooks similarly have a chance of getting wiped blank.
  • Super Weapon, Average Joe: Humanoid monsters can find and use wands. This can lead to very weak monsters killing the player with ease. This type of unfair fatality is often called "gnome with the wand of death." (That can literally happen — gnomes are a common and usually wimpy enemy, but if one of them gets its little hands on a Wand of Death, you're in for a nasty surprise.)
  • Swallowed Whole: Can happen with some of the larger monsters. Don't panic, you aren't dead yet...
  • Take Your Time: The final phase of the game starts with fighting the Wizard of Yendor, who remains conveniently unconscious in his tower until you decide to fight him (though monsters might wake him up with a spell if you hang around on his screen too long). There's no time limit on the sub-Quest, either, no matter how urgent your quest leader might make it sound.
  • Taken for Granite: From the cockatrices. If you manage to kill the 'trice, you can then wield its corpse, turning its power against your enemies. Make sure to wear gloves, though, and don't trip.
  • Technical Pacifist: invoked The requirement for a Pacifist Run to be recognized by the game is that you don't personally kill anything. Leading an army of high-level pets through the dungeon and letting them slaughter everything you meet is just fine (you can even attack enemies and keep the pacifist conduct so long as you aren't the one who lands the killing blow).
  • Tech Points: You need both "skill slots" (gained through Experience Points) and a certain number of successful uses of the item/spell in question to advance a skill.
  • Teleporter Accident
  • Terminal Transformation: When a creature without the ability to control its transformations is hit by the polymorph spell or trap, there's a small chance it will experience "system shock" from the strain of the sudden transformation. This kills monsters instantly, while the player will take a random amount of damage between 1 and 30 (which can still kill you if you were at low HP or just very unlucky).
  • Throw the Book at Them: Unusual move, but if it'll save your behind, you shouldn't discount it. Spellbooks can also be wielded.
  • To Hell and Back: The bottom (second) half of the game takes place in Gehennom. Earlier NetHack versions literally had Hell instead.
  • Tomato in the Mirror: When you talk to one of the Riders in the endgame (of which only Famine, Pestilence, and Death appear as enemies), they say "Who do you think you are, War?" The Ambiguous Syntax makes the meaning unclear, but a comment in the source code spells it out - only three of the horsemen appear as enemies because the player is War.
  • Too Awesome to Use: If you come in with the hoarding attitude, it can take a while to get used to the idea that it's OK to use two charges from your wand of fire on dungeon level three as long as you don't die.
    • One clear example, the scroll of Scare Monster. You get one, maybe two uses before it crumbles to dust. Early on engraving Elbereth in the dust works almost as well, and is repeatable. Late game opponents aren't affected by the scroll.
  • Totally Radical: If you end up hallucinating, man.
  • Touch of Death: A couple of high-level monsters can do this. Getting the proper preventative gear is a early-game priority.
  • Tough Beetles: Carnivorous giant beetles are some of the many monsters represented by a glyph, together with ants and bees. Though they are very slow, their bites are very damaging, and they can kill an unprepared careless adventurer.
  • Trial-and-Error Gameplay: The player is supposed to make out most gameplay mechanics this way. In a game with an immense game world, permanent death, and most errors leading to said permanent death. No wonder that players doubt the possibility of Ascending without reading spoilers. The game does provide an Oracle, a special monster which gives valuable advice about the game, but it has great limitations on its consultations.
  • Turn Undead:
    • Spell and wand of turn undead both fire a beam that can damage and scare undead enemies and also, for the sake of a pun, revives corpses (turns them undead, geddit?). It also rejuvenates eggs.
    • The "#turn" extended command defaults to casting a spell of turn undead (if you have it), unless you're a Knight or a Priest. For these two, it's a special prayer that takes a few turns and can scare/pacify/kill undead within line of sight and range.
  • Underground Monkey: The standard game is constructed entirely of ASCII characters, leading to a lot of creature-overlap. You definitely still don't want to confuse a dwarf king with a mind flayer (both are a purple h). Or a mordor orc with a floating eye (one a dark blue 'o', one a dark blue 'e'.) Major variants contain MONSTERCOLOR option that allows player to change the interface, or alternate tilesets can be installed to supply more information.
  • Unexpected Gameplay Change: The Rogue Level, which is a level that resembles Rogue. The graphics become entirely monocrome, doors cannot be locked or closed, and monsters are all represented as uppercase letters.
  • Unicorn: There are three different types: black (chaotic), grey (neutral), and white (lawful); each will be friendly to characters of their coresponding alignment and hostile to other alignments. They increase your luck when given gems, can teleport, and their horns can cure most of the bad status conditions in the game.
  • Unicorns Are Sacred: Killing a unicorn of your alignment incurs a sizable penalty to your Luck Stat. Sacrificing a unicorn of your alignment is generally a good way to suffer Yet Another Stupid Death, by way of invoking your god's wrath—and if it's on a cross-aligned altar, it'll change your invoked Character Alignment, which is one of the easiest ways to render the game Unwinnable. Sacrificing a unicorn of any alignment on an altar of the same alignment will also invoke that god's wrath. On the other hand, sacrificing a cross-aligned unicorn on a co-aligned altar pleases your god.
  • Unidentified Items: The Trope Codifier. It also has a spell (either by direct casting or by scroll) for the purpose of identifying unknown items, and a separate one for checking if it's cursed. Equipping an unknown amulet without checking either is a good way to end up with an Amulet of Strangulation that you can't un-equip in time.
  • Unusable Enemy Equipment: Not in this game. If a critter has it, you can kill him and use it. (An exception being said critter's body; you may or may not get a corpse.)
    • This is particularly frustrating with Auto-Revive, as monsters can use it too. Or the Wand of Death. Or that potion of gain level. The monsters would love a chance to use their equipment. And they'll pick it up off the floor to hand it to you.
    • Monsters have a starting inventory and also randomised death drops ("That was my prized wand of nothing, You Bastard!! I was saving that!" grunts the orc), though sometimes it can be hard to tell the difference if the monster dies without a chance to use the item.
  • Useless Useful Spell: The wand of death/finger of death spell is rare and ruinously expensive to cast, and many of the strongest enemies are undead (and therefore immune) or respawn quickly.
  • Vague Hit Points: The game doesn't show hit points of enemies at all, nor how much damage you deal to them. (You can probe enemy HP with wands, spells, or a stethoscope, but that's the only way to find out).
  • Video Game Caring Potential:
    • Helping a monster out of a pit might make it peaceful, and you also might get an alignment boost if you're Lawful.
    • Caring for your pet is this, as you're encouraged to keep it with you and letting it die gives a luck penalty.
  • Video Game Cruelty Potential: Have a chat with the nurses. They're not mean! They'll go right on trying to get you to take off that armor and put away that weapon. They'll heal you! And they'll keep trying to heal you even as you chop them up and tin them with your tinning kit.
  • Video Game Cruelty Punishment: Your patron god has very firm ideas on what is and is not right action. This doesn't mean you're supposed to be well-behaved. It means you're not supposed to be caught. Or, in some people's minds, it means surviving the very wrath of God. Which is doable. You can survive the lightning bolt with an amulet of reflection, and the wide-angle disintegration beam by eating a black dragon's corpse. And best of all? If you do, your god says "I believe it not!"
  • Warp Whistle: The wizard's quest artifact, the Eye of Aethiopica. Invoking it lets you travel to any dungeon branch.
  • Weaksauce Weakness: Medusa can be insta-killed by a mirror, or the Reflection property.
  • We Buy Anything: Most shops specialize and will only buy what they sell, and all shops have a limited amount of money with which to buy stuff from the PC, although shopkeepers will offer store credit instead when they can't pay you in cash anymore. On the other hand, any shop will sell the player anything that comes into the shopkeeper's possession by other means. This can be useful for price identification.
  • Weak, but Skilled: Several classes. Also a good mindset for the player themselves, especially in the early game.
  • Weaponized Offspring: It's possible for a female character polymorphed into a monster to lay eggs. Cockatrice eggs can be thrown in order to stone an enemy. Throwing eggs you laid results in a luck penalty though. Alternatively a character that finds an egg can carry it with them, and it may become a tame monster upon hatching.
  • Weapon of X-Slaying: Orcrist and Sting (orcs); Ogresmasher, Giantslayer, Werebane, Demonbane, Dragonbane, and Trollsbane (Exactly What It Says on the Tin); Scepter of Might (non-coaligned monsters); Sunsword (undead); Vorpal Blade (jabberwocks - it always decapitates them, instead of the normal 5% chance per attack).
  • A Winner Is You: If you fight, sneak, and fast-talk your way through 45 to 53 levels of Everything Trying to Kill You, both ways, plus 5 bonus endgame levels, over what can be weeks of playtime and hundreds of thousands of moves, you get this:
    An invisible choir sings, and you are bathed in radiance...—More—
    The voice of [your God] booms out: "Congratulations, mortal!"—More—
    "In return for thy service, I grant thee the gift of Immortality!"—More—
    You Ascend to the status of Demigod[dess]...—More—
    Do you want your possessions identified? [ynq] _
    • Adding insult to... insult, if you win, the line in your log file that normally says "Killer: [thing that killed you]" instead says "Killer: ascended." Which is technically true, since you've left the mortal world, but still.
  • Wishing for More Wishes: The potential to do so is highly restricted:
    • Wishing for a Wand of Wishing will give you a cancelled one (9/10) or one with no charges (1/10).
    • Wishing for a Magic Lamp will give you a regular Oil Lamp.
    • You can, however, wish for (blessed) scrolls of charging, which can be used to recharge an existing Wand of Wishing with more wishes.
  • With This Herring: The Tourist class is the most obvious example, but several other classes qualify.
  • Wizard Needs Food Badly: In an exception to Bottomless Bladder, the PC needs to eat, with the PC fainting if s/he gets hungry enough, and eventually dying of starvation. If your character class is a Wizard or Valkyrie, or your character race is Elf, the game will actually use this phrase, in one of the game's many Shout Outs.
  • Yet Another Stupid Death: The Trope Namer. While it is possible to be merely surrounded and overpowered by fearsomely strong monsters, sometimes you might just fall prey to some lowly humanoid who happens to have found a wand of Death and zaps you with it, for example.
  • You Will Not Evade Me: Once you've woken him up, The Wizard of Yendor will pursue you all the way to the elemental planes. If you kill him he revives after a while. Several high-level monsters, including the Wizard, will teleport to your location if you try to run away from the fight but are still on the same level. All of them combine this with "Get Back Here!" Boss, for maximum annoyance.

You fall below the bottom of the page! 
You die...
Do you want your possessions identified? [ynq] (n) _