Game stages

Nethack can be thought of to be made up of several stages of gameplay.

The Early Game

The first stage is the early game where survival and sometimes securing food is of supreme importance. For many roles, the starting pet is likely more powerful than the character itself. Securing basic armor and weaponry is a top priority; use your pet to test the BUC of items before you use or wear them. When you are weak with hunger, use the #pray command to fill your stomach; save permafood for when you cannot pray. Above all else, take it slow and be careful! The early game is almost definitely the most difficult stage of NetHack.

Early Game Threats

Ranked roughly in order of danger from most to least.

• Team a: As a rule of thumb, any monster represented by an a is a huge threat to an early character. They have high speed, and get multiple attacks on each of their many turns. To top it off, all of these monsters are generated in groups. Engrave Elbereth at first sight with these creatures, even if just with your fingers. Using attack wands is not out of the question either.
  • a Soldier ants and a Killer bees can poison you to reduce your strength, hit points, or even cause instant death if the RNG hates you. Magic cancellation will help block the poison but not the physical damage.
  • a Fire ants cannot poison you, but instead can light you on fire, causing scrolls to burn, potions to boil, and some armor to smolder. Again, magic cancellation can help somewhat by blocking the fire damage, but not the physical damage.
  • a Giant ants are mercifully much weaker than their soldier cousins, but are not to be underestimated; many a character has been killed by these insects.
  • a Giant beetles are an exception; they are very slow and have only one attack. Characters can easily use hit and run tactics to defeat them.
• q Leocrottas: They are fast enough to get 3 turns for every 2 of a character without speed, and have three highly damaging attacks. They thankfully lack any resistances and have low MR, meaning that attack wands are quite useful. They respect Elbereth.
• uuu Unicorns: Unicorns have potent attacks, but will try to remain a knight's move away from you. A hapless player with speed can end up adjacent to one however, and it will continue attacking until one of you dies. Use Elbereth or pacify it by throwing a Gem at it, which may also alter your luck; see the main article for details.
• @ Lycanthropes: Were-creatures such as the Werejackal and the Wererat are likely to be the first shapeshifters encountered, and are thankfully limited to just two forms. They are still a threat however, due to their infectious bite and ability to summon up to five normal animals to tear you to shreds. Elbereth will only work on werecreatures while they are in animal form. Should you be infected with lycanthropy, you should soon eat a Sprig of wolfsbane or quaff a Potion of holy water to cure it; if you have neither, you should pray as soon as it is safe to. Note that for one turn after a werefoos transformation to animal form, it will ignore Elbereth, giving it an opportunity to infect you.

These monsters require special precautions but are not especially dangerous if handled correctly.

• u Ponies d dogs and f cats: The three starting pets. All of these species are much faster than characters, and have strong attacks. They can be tamed by throwing food they like at them (they will eat it) or pacified by throwing any other type of food. You might consider saving some tripe (for cats and dogs) and fruits or vegetables (for horses), but even a food ration or tin will make them stop killing you. Eggs, melons, and cream pies will usually be destroyed by throwing them, preventing them from taming or pacifying your target. See diet for details. As usual, they respect Elbereth.
• e Floating eyes: Floating eyes are very slow and cannot directly damage you. They are still very dangerous, due to their passive attack - should you fight them in melee, you will often be paralyzed for several hundred turns, during which you are a sitting duck. Attack them with ranged weapons or apply a Polearm, or simply ignore them. If they leave a corpse, be sure to eat it, as intrinsic telepathy is valuable.
• m Mimics: Pose as items in shops and kill unsuspecting players. They hit very hard and can grab onto you but move very slowly. Elbereth is very useful against one that grabs you. See the mimic page for more advice.

The Mid Game

In the middle game survival is less of a pressure and the game is about completing an ascension kit. The distinction between early and mid game isn't clear, with definitions ranging from reaching having reached Sokoban and Minetown, to collecting the Sokoban prize, to the point at which you no longer fear team a. The floors between the Quest portal and Castle are almost certainly midgame territory.

Mid Game Threats

• L/L Liches and demiliches: These undead monstrosities are likely to be the first truly threatening spellcasting monsters the player encounters. Normal liches are relatively slow, but have a toolbox of spells allowing them to stun you, lower your strength, curse your items, or destroy your precious armor. Demiliches are faster, and can also alert other monsters of your presence. High level demiliches can even cast touch of death. Elbereth can prevent them from touching you or using their worst spells on you, and it is therefore highly recommended. Blessed scrolls of genocide are often used on liches, and has the benefit of also annihilating their stronger cousins, master and arch-liches.
• h Mind flayers: These flying abominations are not spellcasters, but instead have the ability to suck your brain. This attack drains your intelligence, and can also cause you to forget identities and level layouts. If they reduce you to below 3 intelligence, you will die instantly and cannot be saved even with an amulet of life saving. Attack them from range whenever possible; if you must fight them in melee, wear a (preferably greased) helmet and use Elbereth religiously. If they are within one turn's movement of you you should engrave Elbereth with a guaranteed one turn source, e.g. a wand of fire or a magic marker. After they are dead, you can use a unicorn horn to restore your intelligence, but you will not recover lost identities or maps. Genocide is also popular, but beware: if you are a dwarf, blessed-genociding 'h' will instantly kill you.
• H Titans: While normally quite rare, 50% of Medusa levels include one. They are almost always peaceful to lawful characters, but neutral and chaotic characters are out of luck. They are probably the first monster you encounter capable of casting Summon nasties, and worse, they are immune to genocide. They respect Elbereth, but be wary as several of their summoned minions ignore it.
• ; Sea monsters: Two sea monsters in particular, the ; giant eel and the ; electric eel, possess a two-move instant death attack in drowning. The move will fail if you wear a greased or oilskin cloak, however. If you lack either, be adjacent to water as little as possible. Electric eels can also destroy your rings with their electrical attacks - including a worn ring of levitation. They are sometimes genocided, but less commonly than the previous two monster types. Eels and sharks are guaranteed around Medusa's Island and in the Castle moat. They will appear in swamps as well, but those are rather rare.
• c Cockatrices: These monsters are possibly the most detailed monsters in the game; it is important to understand what will and what will not petrify characters. The main article goes into detail, but the gist is that touching a cockatrice, living or dead, in any way, will kill a character instantly. If gloves are worn, they can be touched with your hands, but beware of wielding their corpse - should you fall in a pit or down stairs, you will touch them no matter what you wear. Should you begin to stiffen from their hiss, eat a lizard corpse or cast Stone to Flesh on yourself posthaste; if no other option is available, pray. With correct precautions, they become less dangerous and more of a powerful weapon. Just beware of leaving them on the floor, in case you walk over it while blinded or have it used against you by an intelligent foe.
• R Rust monsters: These monsters can be unbelievably irritating. Both their main attacks and their passive attack will cause metal items to rust, reducing their effectiveness. They will also eat any metal items they find, including good items you may have wanted to obtain. If they are alone, you can simply punch them to death while wearing no metal armor uncovered by a cloak; they can do no physical damage. If not alone, use the almighty E-Word or zap them with wands and spells.
• H Minotaurs: The last new midgame threat. These monsters ignore Elbereth and have very high damage, but they also have very low magic resistance. They are generated by the summon monsters spell and can be created inside any labyrinth. They will not normally appear before late game, but the Castle contains a small piece of labyrinth and there can be up to 3 complete labyrinth levels between Medusa's level and the Castle giving you plenty of chances to meet them early. A minotaur at the Castle is particularly dangerous because the maze is so small; if it appears there you are usually forced to fight it. Once you obtain the Castle's wand of wishing and begin exploring Gehennom these usually cease to be a threat.

The Late Game

In the late game, survival is almost guaranteed (bar those YASDs that an amulet of life saving could have saved you from), and the goal is to get the Amulet of Yendor and resurface. The late game is generally said to start either when you get the wand of wishing from Castle, or when you beginning exploring Gehennom; the difference being that some players in some roles (e.g. Samurai) do the Quest after the Castle.

Late Game Threats

• YASD: There is really no reason to be dying at this point except high conducts.
  • H Minotaurs: If something is going to kill you in melee, this is it.
  • h Mind flayers: Amnesia is still a substantial set back and a brainless death is still possible. And remember that unlike most of the post-Castle blunders you could make, all the amulets of life saving in the world won't save you from brainlessness.
  • P Green slimes: Not especially dangerous, but (rarely) being touched by them or (definitly) eating them can start a long delayed instadeath (sliming) curable by fire. Be aware that they exist.
  • & Jubilex: A major demon who inhabits his own swamp, guaranteed to appear in Gehennom. He is easy to kill but will almost surely infect you with a deadly sickness at least once, which you must remember to cure with your unicorn horn.
• c Cockatrices: A monster wielding a cockatrice corpse is one of the few truly frightening things, and the cockatrice itself presents many possible YASDs
• L Master liches and Arch-liches: These purple Ls will cast all of the normal lich's and demilich's spells, in addition to summoning nasties and using touch of death. They will begin appearing frequently in Gehennom.

The Ascension Run

Finally, on the run your final death is a (slim) possibility again while racing to ascend. Your character is likely fully equiped and very strong, but there are a few things to worry. This stage of the game begins by recovering the Book of the Dead.

It's worth noting that most players treat "end game" as a synonym for "Ascension Run", but Nethack itself reserves the title "End Game" for the Elemental Planes and the Astral Plane (though it uses "Elemental Planes" internally for the Astral Plane as well as the other four planes). Most players refer to those as just "the Planes".

Ascension Run Threats

• The same warnings about YASDs from the late game apply here, but with a few additional notes.
• & The Riders: Unique monsters you will meet on the Astral plane. Read up on them.
• @ The Wizard of Yendor: The Wizard will return from the dead an infinite number of times, and will not stop appearing until you reach the Astral plane. Even while dead he will strike out at you.
• h Mindflayers: If you get amnesiaed now you will have to remap the levels you lost with Rodney on your tail.
• % Cockatrice corpses: These are a common choice on the ascension run, especially on Astral; as always, be careful with them.
• The Astral plane, the last level in the game, is by far the place where most ascension run deaths take place. Move slow and play carefully. Request the help of the players in #nethack if you need it.