Welcome to Eva's Nethack page! I noticed on the newsgroup rec.games.roguelike.nethack that several false rumours about the game frequently circulated and had to be debunked. I decided to create a web page dedicated to these myths about Nethack and the facts behind them. The information on this page has all been checked by source-diving and/or wizard-mode experimentation in Nethack 3.3.0 or later versions, and I believe that it is also correct for Slash'Em. Many thanks go to Dylan O'Donnell for the information on converting yourself that inspired me to create this web page in the first place, and for several corrections including alignment penalties for killing peaceful monsters. If you find anything wrong please email me.
MYTH: If you wear a helm of opposite alignment before the quest, your quest leader will not let you in, and your game will be unwinnable.
FACT: Simply remove the helm and you will be allowed on the quest again. A helm of opposite alignment only causes a temporary alignment change which is reversed when the helm is removed. (Since it takes away all divine protection, it's still not a good idea to wear one.)
If you convert yourself permanently (by sacrificing on a non-coaligned altar), then you will render your game unwinnable. You cannot convert back, and your quest leader will not be fooled by your wearing a helm of opposite alignment.
Under what circumstances will you convert yourself permanently? There is a myth about this too, and I am greatly indebted to Dylan O'Donnell for sorting me out.
MYTH: If your god is angry with you when you attempt to convert an altar, you will be converted to the altar's god instead.
FACT: If your god is angry but your alignment is positive, you can still convert altars. Your god will still be angry, but you can use the newly coaligned altar to mollify him.
You will convert yourself if you try to convert an altar when your alignment is negative, or if you sacrifice a unicorn of your own alignment on another god's altar.
MYTH: Unaligned altars (altars to Moloch) can't be converted; it is harmful to even try.
FACT: Unaligned altars in Gehennom cannot be converted. Unaligned altars outside of Gehennom, such as those on some quests, can be converted normally. It is, however, wholly impossible to convert oneself to Moloch.
There seems to be considerable confusion over the precise penalties for killing tame and peaceful monsters.
MYTH: Killing your pet will anger your god.
FACT: This depends on how you kill it. If you kill it in an ordinary way (e.g. in combat), you will ``hear the rumble of distant thunder''. The penalty will be -15 to alignment and -1 to Luck, but your god will not become angry.
If you kill it by displacing it into a trap or water, you will probably (75% chance) ``feel guilty about losing your pet like this''. If you do, then your god will become angry and you will also lose 15 points of alignment.
If you drown it by quaffing or dipping at a fountain or kill it with a scroll of genocide, there is no penalty.
The penalty for killing a peaceful monster is one or more of loss of protection, loss of telepathy, reduced luck and reduced alignment, depending on the type of peaceful monster killed.
Quest friendlies cause you to lose vast amounts of alignment, coaligned priests carry a penalty of only -2 but should probably not be killed because of the loss of protection, cross-aligned priests carry a small alignment bonus, and priests of Moloch carry a large alignment bonus. If the monster is still peaceful when it dies (as mentioned above, this is unlikely), there is an additional penalty of -5, unless it was a quest leader or guardian or a priest.
MYTH: Prayer timeout is quicker for lawfuls than for chaotics.
FACT: Prayer timeout behaves exactly the same way for all alignments. The myth derives from a bug in Nethack 3.1.3 which caused it to be longer for crowned chaotics.
MYTH: Lawful characters must not rob shops / attack peaceful monsters / eat while satiated / ....
FACT: There are assorted actions (such as robbing shops) for which lawfuls receive a -1 alignment penalty and chaotics receive a +1 alignment bonus. There are other actions (such as eating while satiated) for which only Knights or Samurai are penalised. These class/alignment specific penalties are very minor and can usually be safely ignored. The alignment penalty for killing peaceful monsters is more severe, but applies to all characters. For details of all actions which affect your alignment, see the Appendix to Matthew Lahut's Praying Spoiler.
MYTH: It's safe to unlock doors in Minetown with a key in full view of the watchmen.
FACT: The watchmen will still warn you and then get angry if they notice you doing it. Usually they don't, because unlocking a door with a key normally only takes one turn, while a lock pick or credit card takes longer.
MYTH: If you fall into a pit while carrying a cockatrice corpse, you will turn to stone.
FACT: Falling will only turn you to stone if you are actually wielding the corpse. For details on all the ways in which cockatrices and their corpses can petrify you, see David Corbett's cockatrice spoiler.
Dropping items on altars to see whether they are blessed or cursed works with an altar to any god, even Moloch, although obviously you must not be blind or hallucinating at the time. You can also buy protection from any peaceful priest who is still in a temple of his or her own alignment, even the priest of Moloch in the Valley of the Dead. (Slash'EM players should note that despite appearances, the altar room on the Nightmare level is not a temple, so you cannot buy protection from the priest there.) Dylan O'Donnell's spoiler collection includes more information on donating to priests.
By the way, altars and priests are ``coaligned'' if they are of the same alignment as you, ``non-coaligned'' or ``cross-aligned'' if they are of a different alignment, ``aligned'' if they are lawful, neutral or chaotic, and ``unaligned'' if they are of Moloch. Unaligned altars do not appear in the main dungeon, only in Gehennom and some quests.
Wands of cancellation are not as dangerous as many people imagine, provided that you are careful not to put a charged one into your bag of holding.
Items dipped into holy or unholy water will not blank, dilute, rust, get wet, or suffer any type of water damage. They will simply be blessed or cursed as appropriate. Items dipped into uncursed water will suffer the typical effects of getting them wet.
MYTH: If you pick up corpses and drop them before letting your pet eat them, it will keep it tamer.
FACT: Your pet's apport, or willingness to fetch, can be improved by feeding it personally. However, only treats will work for this purpose, and corpses aren't treats. Tripe rations and meatballs are treats for a dog. Apples and carrots are treats for a horse.
Your pet's tameness, or resistance to going wild, increases whenever it eats, whether you've touched the food or not.
I have written a spoiler with more information about apport and tameness, and Peter Snelling, Boudewijn Wayers and Bryan Butler have written a detailed spoiler on training pets to steal.
MYTH: If you can see invisible, it's a good idea to make your pets invisible.
FACT: This is only applicable to steeds. Invisibility has no effect on monster-vs-monster combat, but if your steed is invisible, monsters will attack you rather than it more often. Whether this is a good or bad thing depends on how strong you are and how much you care about keeping your steed alive.
MYTH: Female characters are less vulnerable than male characters to nymphs.
FACT: Although Nethack has nymphs "seduce" males and "charm" females, the difference in the messages is purely cosmetic and your gender has no effect on your vulnerability to nymphs.
MYTH: If you start a game during a new moon, your base luck will be -1.
FACT: New moons have no effect on your base luck. The only effect they have is that cockatrices are slightly more dangerous. There is a one-point luck penalty for starting or restoring a game on Friday the 13th, and a one-point luck bonus for starting or restoring during a full moon (these can cancel each other out). Boudewijn Waijers and Dylan O'Donnell have written a spoiler giving full details of the effects of time and date on the game.
MYTH: Get teleportitis before eating a tengu because then it's more likely to give you teleport control.
FACT: When you eat a monster which can grant multiple intrinsics, first the intrinsic it will try to grant is chosen at random without reference to your current intrinsics, and then it is determined whether or not it will be granted. Of course, it can only be granted if you don't already have it.
MYTH: Eating a ring of increase damage for the intrinsic will permanently increase your food consumption.
FACT: Eating rings or amulets does not normally increase food consumption (unlike wearing them). The exception is that gaining intrinsic regeneration, conflict or hunger by eating a ring will raise your food consumption by one point every two turns (normal food consumption is one point per turn).
On the subject of rings and food consumption, there is no point in constantly wearing two rings of slow digestion. With one, your food consumption is reduced to 1 point every 20 turns, but with two, it is 1 point every 10 turns, because both rings are causing their "ring hunger" effect. Because of the details of when ring hunger is checked for, it is possible to reduce your food consumption to zero by wearing two rings of slow digestion most of the time but removing each one just before it would cause its hunger effect and replacing it afterwards.
Dylan O'Donnell has written a spoiler on food which includes a list of all factors which affect food consumption.
MYTH: Getting Excalibur is easier for Knights than for any other class.
FACT: Any lawful character of level 5 or higher has exactly the same chance of getting Excalibur by dipping. Excalibur used to blast non-Knights in version 3.3.1, but this bug was fixed in 3.4.0.
MYTH: Excalibur is the Knight's first gift from sacrificing.
FACT: Actually, it cannot be obtained by sacrificing at all, nor can it be generated randomly.
MYTH: Your spellcasting stat (Intelligence or Wisdom, depending on your class) affects your chance of learning spells.
FACT: No matter what class you are, Intelligence affects your chance of learning spells and Wisdom does not. The spellcasting stat applies to the chance of casting spells successfully.
MYTH: Confusing yourself with a forgotten spell is less useful in Nethack 3.4.3 than it used to be, because it might stun you as well.
FACT: It's true that forgotten spells can stun you, but you can simply apply your unicorn horn and try again until you are confused but not stunned. Also, being stunned prevents teleport control from working but does not affect the results of reading any scroll apart from teleportation.
MYTH: The Vibrating Square will move if you drop an object on it or dig down while standing on it.
FACT: The Vibrating Square will never move and cannot be destroyed. Also, it cannot be generated inside a wall or on a trap, although it can be generated under an object. You will feel a strange vibration under your feet whenever you move onto it. This happens whether you walked onto it normally or (level-)teleported there. Even if you are levitating, flying or riding, you will still feel the vibration.
MYTH: Keep your experience level low so that the monsters you encounter while climbing up with the Amulet and in the Elemental Planes will be less dangerous.
FACT: The upper limit on the difficulty level of randomly generated monsters is normally the average of your experience level and your current dungeon level. Once you have the Amulet of Yendor, however, the upper limit increases to the average of your experience level and the dungeon level of Moloch's Sanctum. (There is also a lower limit, but this depends only on the depth of Moloch's Sanctum, not on your XL.) Moloch's Sanctum can never appear above DL:45, and a post-quest character will have at least XL 14 unless they have deliberately level-drained themselves.
The randomly-occurring monster with the highest difficulty level is the arch-lich, at 29. To avoid meeting them, one would need to have XL 12 or less (assuming the shallowest possible depth for Moloch's Sanctum). Most people avoid them by genociding them instead. The second most difficult monster is the Archon, at difficulty level 26, and one would need XL 6 or less to avoid them.
Although the rules for generating monsters of a fixed class are different (monsters of more than twice your XL are less likely to be generated but can still appear), the only place this is likely to cause trouble on the ascension run is the Astral Plane, and then only if master liches and arch-liches have not been genocided.
MYTH: The Wizard of Yendor will reappear one final time when you enter the Plane of Earth, and will never come back again once you've killed him there.
FACT: He can reappear on any of the Elemental Planes after being killed on the Plane of Earth, but he cannot appear on the Astral Plane.