Stoning

In NetHack, stoning or petrification is the process of a hero or monster turning to stone and usually becoming a lifeless statue.

Description

Stoning can occur either instantaneously or as a form of delayed instadeath - both forms of stoning can be reversed by life saving. All potential causes of stoning in NetHack are related to one of three monsters:

• The c cockatrice, which can induce delayed stoning through its attacks, lays eggs that can do the same when consumed by the hero, and can instantaneously petrify any monster that makes bare-skin contact, even with its corpse or tinned meat;
• The c chickatrice, which is a juvenile cockatrice that appears much earlier and poses many of the same threats as the adult cockatrice, but cannot lay eggs and leaves corpses much less often; and
• @ Medusa, whose gaze and flesh can petrify the hero.

The term "footrice" can refer to either the chickatrice, the cockatrice or both monsters, due to the similarities they share. All monster attacks that can turn victims to stone use the AD_STON damage type.

Stoning resistance is a property that prevents either form of stoning from occurring. Golems that do not possess stoning resistance (i.e. all except for the stone golem) and would be petrified will instead transform into a stone golem, including a hero in the form of a golem. Vampires that would turn to stone while in shapeshifted form will instead resurrect into their vampire forms. Medusa is special-cased to only be vulnerable to stoning from her own reflected gaze, and is otherwise immune.

Instant stoning

Instant stoning immediately turns the victim into a statue. All forms of stoning are instantaneous against monsters, unless they are capable of curing it when it occurs - tiny monsters will turn into a pile of rocks rather than a statue. Instant stoning against the hero can occur from any of the following actions:

• Attacking a live footrice through any of the following methods:
  • Unarmed 'weapon' attacks while not wearing gloves - this includes bare-handed attacks, attacking with wielded potions, claw attacks, and touch attacks.
  • Engulfing - this applies solely to digestion attacks in practice, as all other monsters with engulfing attacks possess stoning resistance; digesting Medusa will also turn the attacker to stone.
  • Holding attacks while not wearing gloves and a cloak.
  • Kicking via the command or monster attack while not wearing boots.
  • Using headbutt attacks while not wearing a helm.
  • Bite or sting attacks, including the seduction attack of a foocubus (which is AT_BITE).
  • Tentacle attacks, including the brain-sucking attacks of a mind flayer or master mind flayer.
• Attempting to saddle a live footrice without wearing gloves, or else having the hero's steed polymorphed into one while they are riding it.
• Attempting to untrap a live footrice from a pit or spiked pit without wearing gloves.
• Picking up, throwing, firing, or wielding a footrice corpse without wearing gloves.
  • This includes having worn gloves removed or destroyed while wielding the corpse, or else polymorphing from a form with stoning resistance to one without the property while wielding one.
• Placing a footrice corpse in a container or remove it from a container without wearing gloves.
• Kicking a footrice corpse without wearing boots.
• Falling into a pit, spiked pit, hole, trap door, or the stairs (from fumbling, bring encumbered, or being punished) while wielding one.
• Flying down a hole or trap door while wielding one.
• Falling onto a sink while levitating or flying and wielding one.
• Tripping over a footrice corpse on the ground while fumbling without wearing boots.
• Eating a footrice corpse or tin.
• Fainting from hunger while wielding a footrice corpse.
• Snagging a wielded footrice corpse from a monster by using a bullwhip or grappling hook without wearing gloves - using the bullwhip to pick one up from the ground is fine.
• Stealing a footrice corpse directly from a monster's inventory without wearing gloves.
• Sacrificing a footrice corpse at an altar without wearing gloves.
• Applying a tinning kit to a footrice corpse without wearing gloves.
• Throwing a footrice corpse or egg directly up via < and being hit on the head by it without wearing a helm - the cause of death is listed as "petrified by elementary physics" (what goes up, must come down).
• While blind and not wearing gloves, move onto a footrice corpse, teleport onto one, stop levitation on a square that has one, use near look on a square that has one, or be expelled from an engulfing monster onto a square with one. Safe-moving moving with m will not automatically cause the hero to feel on the ground.
• Meeting the gaze of Medusa, digesting or biting into her corpse, or consuming a tin of her meat.

The following information pertains to an upcoming version (3.7.0). If this version is now released, please verify that the information below is still accurate, then update the page to incorporate it.

Manually flying down a hole or trap door while wielding a footrice corpse will no longer turn the hero to stone.

Delayed stoning

Delayed stoning causes the hero to slowly turn into a statue over the next few turns, with the property removing intrinsic speed when it is applied and abusing dexterity each turn. Delayed stoning occurs from the following actions:

• Hearing a footrice's hissing, which occurs with a ¹⁄₃ chance after its touch attack if the footrice is not cancelled - the hissing itself has a ¹⁄₁₀ chance of initiating delayed stoning, and will always do so on a new moon unless the hero is carrying a lizard corpse in open inventory.
• Eating a cockatrice egg, or being hit by one thrown by a monster.
• Being hit by a cockatrice corpse wielded by a monster.
• The brain-sucking attacks of a mind flayer or master mind flayer - both delayed and instant stoning occur, so this is only seen if life saving prevents the instant stoning.

Delayed stoning prints the following messages based on how much of the hero's body is tone and how many turns they have left to live:

Turns to live	Effect	Message
5	"You are slowing down."	Intrinsic speed is removed. The hero has two turns left to act.
4	"Your limbs are stiffening."	Occupations are interrupted unless the hero is opening a tin (which can potentially save them from becoming a statue). The hero has one turn left to act.
3	"Your limbs have turned to stone."	The hero's limbs are now unusable: this immobilizes them, interrupts all occupations, and also removes the wounded legs property if they are not currently riding.
2	"You have turned to stone."	The hero goes deaf, and nausea and sliming are aborted.
0-1	"You are a statue."	The hero has become a lifeless statue - if the hero has life saving, it will activate and revive them. Otherwise, the game ends.

Curing delayed stoning

The following actions by the hero can cure stiffening and completely reverse delayed stoning:

• Biting into the corpse of a lizard, biting into the corpse or glob of any acidic monster, or eating their tin.
• Biting into the glob of a green slime - the glob is acidic, but will also inflict sliming.
• Quaffing a potion of acid.
• Casting the stone to flesh spell directed at themselves.
• Successful prayer to the hero's god - this will pause the stoning timer as soon as the prayer begins, and delayed stoning is considered a major trouble.
• Polyself into any golem or any monster with stoning resistance.

A worn amulet of life saving does not cure delayed stoning, but reverses its effects after the hero becomes a statue.

Monsters that are subjected to stoning will attempt to cure it immediately if they have a means to:

• Monsters can use lizard corpses as defensive items, and will eat lizard meat to cure stoning. Monsters with a tin of lizard meat that are being turned to stone have a ²⁄₃ chance of opening it. A monster with intrinsic speed loses the intrinsic if it eats a lizard corpse, even if it was not done to cure stoning.
• Monsters will pick up acidic corpses, such as those of acid blobs, to use for similar purposes.

Strategy

Stoning is one of the more commonplace causes of YASD, with a majority of them tied to footrices. It is important for every hero to recognize when the danger of stoning is present, and be able to act promptly if they are subjected to delayed stoning - most players set MSGTYPE strings in their options to stop the action when a message related to stoning or any stoning sources is printed.

Prevention

Naturally, one of the best methods to deal with any form of stoning is to avoid it in the first place: wearing gloves is strongly recommended when dealing with footrices, and a source of blindness or reflection will block Medusa's gaze. Lizard corpses never rot or become tainted - it is always worth carrying at least one or two in open inventory for emergencies, even as a hero observing the vegetarian or vegan conduct. Curing stoning also does not require that the hero finish the corpse, and whatever was turning them to stone will likely interrupt the process, so a single lizard corpse can save the hero from stoning a few times before it is fully consumed.

One of the more critical factors in being able to cure stoning is the ability to act quickly: the process takes 5 turns and robs the hero of intrinsic speed, and being burdened or worse will further reduce what little time they have to act. If at all possible, try to remain unencumbered and keep a backup source of speed on hand - if you are encumbered from using a bag or other container to carry a lot of items, you should ideally be able to drop it at a moment's notice if you encounter a stoning threat. An extrinsic source of speed is not required, but can prove convenient, and keeping track of prayer timeout is valuable as well; if all else fails, a worn amulet of life saving can reverse the process. Eating a glob of green slime is a last resort, since the hero will then have to cure the sliming process before it irreversibly transforms them.

For heroes determined to maintain vegan or vegetarian conducts, identifying and holding onto potions of acid, being able to reliably cast stone to flesh, or obtaining and blessing tins of acidic monsters are some viable alternatives - all of these methods also have significant tradeoffs, however:

• Potions of acid are rare to come across, and most monsters that generate with the potions or find them will throw them at you to inflict damage. Keeping them in open inventory also exposes them to possible destruction from fire and cold damage, as well as losing them by accidentally stepping into a moat or pool (which causes acid to react and explode).
• The stone to flesh spells requires the hero to increase their skill in healing spells, as well as being able to reduce the spell's failure rate to 0% and have 15 energy in order to cast it. This is generally most feasible for casting-focused heroes, and even then the most likely roles that can reliably turn to this spell are Healers, Priests and Wizards. Additionally, the spell will turn mineral items in the hero's open inventory into ineffective meat, though this is preferable to becoming a statue with all your possessions intact.
• Relying on tins requires a blessed tin opener and/or a blessed tin, both of which should be in open inventory to save valuable time; a blessed tin opener immediately opens a tin in one action, while a blessed tin will open in 0-1 turns without a blessed tin opener (and introduces the possibility of being interrupted). Applying the tin opener will wield it without taking a turn, provided you then immediately open a tin.

Cancellation can remove a footrice's ability to induce stoning by preventing them from hissing, but does not cancel their intrinsic stoning abilities. Cancelling Medusa renders her gaze completely ineffective, though her corpse and tin will still turn their eaters to stone.

Monsters with stoning resistance

In addition to lizards, the following monsters have stoning resistance and are valid forms for polymorph, allowing a hero to potentially save themselves from delayed stoning by polymorphing into them:

• Gargoyles are humanoid monsters that can wear all armor and have an impressive base AC of -4, though their base speed is slower at 10.
• Air elementals are blind and cannot wear armor, but boast a movement speed of 36 and inflict high non-elemental damage quickly.
• Xorns are capable of phasing and can wear gloves, boots, helms, and shields, though they move at a slow speed of 9 and transforming into one breaks all worn body armor.

History

From Hack 1.0 to Hack 1.0.2, stoning is only possible from a cockatrice's hissing, and is an instadeath if it occurs. Hack 1.0.3 introduces gradual stoning, and gives lizard corpses their anti-stoning functions.

In NetHack 3.4.3 and previous versions, stoning is subject to a few bugs:

• Smashing a wielded potion of polymorph over a monster while not wearing gloves will stone the hero if the monster turns into a cockatrice. This is bug #C343-31, and was fixed May 2004.
• Jabberwocks can wield items and hit monsters with them, but secondary effects will not trigger: footrice corpses will not petrify monsters, silver weapons do not deal extra damage to silver-haters, and so on. These are bugs #UNL343-080 and #UNL343-081, and they were fixed in 2011 via commit 164f498a and commit 8dfb62a9.

Variants

Variants of NetHack frequently add new sources of stoning, as well as new means of curing it (which at minimum includes the addition of other acidic monsters).

SLASH'EM

In SLASH'EM, there are two additional monsters that cause stoning: the thick-hided basilisk and the small frequently-hiding asphynx. Both are significantly higher-level than the cockatrice; on average, fights against them will be longer, increasing the chance that one of their attacks may start turning you to stone. They also use different glyphs than cockatrices, meaning that a blessed scroll of genocide is no longer an easy solution.

SLASH'EM also introduces the amulet versus stone, which will save your life against stoning in the same manner as an amulet of life saving, costing a point of constitution and incrementing the "killed" counter. The amulet, however, is not destroyed in the process unless it is cursed; otherwise, its beatitude changes from uncursed to cursed, or from blessed to uncursed. Thus, with a sufficient supply of holy water, one amulet can prevent many stoning YASDs.

UnNetHack

In UnNetHack, stoning resistance is conferred by chromatic dragon scales and chromatic dragon scale mail.

dNetHack

dNetHack introduces several new acidic monsters whose corpses, tins and blood can cure stoning:

• shoggoths
• blood bloaters
• blue and yellow dragons and baby forms (blue is new)
• flux slime
• darkness given hunger

In addition, all varieties of cave lizard and giant turtles will cure stoning when eating their corpse or tin.