Poison
- This article is about the damage type. For sickness from consuming tainted corpses, see food poisoning.
Poison is a damage type that appears in NetHack, and can occur from various hazards, attack methods and items that can all be potentially lethal to both heroes and monsters.
Description
As indicated above, poison damage can occur from several sources:
- The venomous melee attacks and breath weapons of various monsters.
- Being caught in clouds of poisonous gas.
- Heroes and monsters using poisoned weapons.
- Falling victim to spiked pits or certain other traps.
- Eating a poisonous corpse—this is not to be confused with food poisoning, which occurs independently from eating any corpse that is too old.
- Quaffing a potion of sickness, which can damage one of the hero's attributes.
Poison is capable of weakening a hero or monster with additional HP loss, and for the hero this may be combined with damage to one of their physical attributes.[1] Poison from spiked pits, poisoned weapons, poison clouds, and poisonous attacks from monsters also have a chance of outright killing their victims:[2] The chance of attribute loss and instant death is applied per exposure, rather than per source, and the instadeath chance is always 1⁄5 the chance of attribute loss, with extra HP damage occuring otherwise—said damage will be 1-6 HP for thrown weapons and 6–15 otherwise. The game will print a message indicating when the effects of poison from any source occur.[3]
Poison resistance is a property that protects a hero or monster from poison damage by reducing or nullifying the amount of damage dealt, and it also prevents the possibility of instant death from exposure to poison.[4] Poison resistance also lowers the severity of the effects from quaffing a potion of sickness.
The following information pertains to an upcoming version (NetHack 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.
Per commit d0b11fd2, poison no longer instantly kills the hero, and the effect is replaced by an additional 6 + 4d6 damage, half of which is subtracted from their maximum HP, and harsher lowering of attribute points.Poisonous attacks
Poison attacks can have one of three damage types:
- Poison that drains strength, which uses the AD_DRST damage type flag[5]
- Poison that drains dexterity, which uses the AD_DRDX damage type flag[6]
- Poison that drains constitution, which uses the AD_DRCO damage type flag[7]
A hero hit by a poison attack that is not blocked by magic cancellation has a 1⁄8 chance of the poison triggering:[8] this has a further 1⁄6 chance of decreasing the affected attribute, a 1⁄30 chance of being fatal outright, and otherwise deals .[9] Poison resistance blocks all of these effects, with a message printed accordingly.[10]
Poison breath attacks leave a trail of poison clouds behind covering the path of the ray, and any such rays of poison that hit a hero directly have a 1⁄3 chance of draining 2-4 points of dexterity (despite the attack using the AD_DRST flag), with a 1⁄15 chance of being immediately fatal, and otherwise deals 6–15 extra damage, with all of these effects blocked by poison resistance.[11]
Of note is that the guardian naga's spitting attack uses the AD_DRST damage type flag, even though it behaves as non-damaging blinding venom upon hitting a hero or monster—poison resistance therefore does not block this effect. Additionally, the erinys has a weapon attack that is poisonous independent of whether the physical weapon is poisoned.
A hero that is polymorphed into a monster with a poisonous attack and successfully lands one against a target without poison resistance has a 1⁄8 chance of the poison taking effect, with a further 1⁄10 chance of being outright fatal and otherwise dealing 6–15 extra damage.[12]
Magic cancellation can block the poison of melee attack types (including the erinyes' weapon attacks) from taking effect, but not from breath weapons or spitting attacks.
Poison clouds
Poison breath, scrolls of stinking cloud and lava plumes on the Plane of Fire all produce poison clouds that cause any heroes and monsters caught within them to take constant poison damage unless they have poison resistance or move outside of the clouds, and also causes coughing and blindness even if they have poison resistance.[13][14] See the linked article for more details on the dungeon feature.
Poisonous monsters
Several monsters are poisonous to consume, whether by eating their corpse or glob, or else by consuming them directly with a digestion attack: the M1_POIS monster flag used within monst.c governs whether or not a monster is poisonous.[15] The hero has a 4⁄5 chance of being poisoned from eating a poisonous monster or its corpse, which causes up to 15 HP of damage and drains 1-4 points of strength[16]—this does not apply to tins of poisonous monsters, presumably due to the most edible parts being preserved by the tinning process (including ones the hero makes with a tinning kit). Poison resistance blocks these effects, and pets eating corpses and globs will avoid poisonous ones unless they have poison resistance.
While eating a poisonous corpse or glob does not have a chance of instant death like other sources of poison, HP loss and strength drain always occur if the hero is poisoned and can still kill them as normal. A monster's corpse or body being poisonous is independent of that monster granting poison resistance when eating it, let alone the monster having poison resistance or even an attack that inflicts poison—see the list of poisonous monsters below for details. Additionally, a corpse being poisonous is independent of food poisoning from an old corpse: both hazards are separate and check for different resistances (poison resistance versus immunity to sickness), though they can occur simultaneously, e.g. a kobold corpse left by a kobold zombie or mummy.
The following monsters are considered poisonous to eat or digest directly:
- a ant or other insect: a killer bee, a soldier ant, a giant beetle, a queen bee
- d dog or other canine: @ / d werejackal, @ / d werewolf
- g gremlin
- i imp or minor demon: i manes, i homunculus, i lemure
- all k kobolds
- r rodent: r rabid rat, @ / r wererat
- s arachnid or centipede: s giant spider, s scorpion, s Scorpius
- x xan
- A couatl
- B vampire bat
- D dragon: D baby green dragon, D green dragon, D Chromatic Dragon
- F yellow mold
- all L liches
- all M mummies
- N guardian naga
- P green slime
- Q quantum mechanic
- S snake: S snake, S water moccasin, S pit viper, S cobra
- all V vampires
- all Z zombies
- ' iron golem
- @ human or elf: @ Medusa, all werecreatures
- all & major demons except sandestins and the Riders
- ; jellyfish
- : salamander
Poisoned weapons
Various projectile weapons can be poisoned:
- Darts, shuriken, crossbow bolts, and all types of arrows have a 1⁄100 chance of generating as poisoned.[18][19]
- A hero can poison projectiles of the same type by dipping them in a potion of sickness.[20]
- A chaotic hero has a 1⁄100 of compatible projectiles in their starting inventory generating as poisoned.[21]
- Orcish arrows generated in a monster's starting inventory are always poisoned.[22]
A hero without poison resistance that is hit by a poisoned projectile has a 4⁄5 chance of losing 1 point of strength, a 1⁄30 chance of the poison being fatal, and otherwise takes up to 6 HP of extra damage, with the chances applied for each individual projectile and all of these effects being blocked by poison resistance.[23][24] A monster without poison resistance that is hit by a hero's poisoned weapon or projectile takes up to 6 points of additional damage, with a 1⁄10 chance of the poison being fatal[25]—a monster hit with a poisoned weapon or projectile thrown or shot by another monster takes up to 6 points of additional damage, with a 1⁄30 chance of the poison being fatal.[26] Poisoned weapons and projectiles that hit a hero or monster ignore magic cancellation.
A hero's weapon that is poisoned has a weight-based chance of its poison wearing off after each hit.[27] Lawful heroes take a -1 penalty to alignment record for using a poisoned weapon (with a minimum of -10), and Samurai take a separate penalty to alignment record for using poisoned weapons.[28][29] Poisoned weapons that are dipped into a potion of healing, extra healing or full healing will lose their poison.[30]
Eating a poisoned weapon while in the form of a metallivore or gelatinous cube has the same effects on strength and HP as eating a poisonous corpse, including poison resistance (which cubes naturally have) blocking both effects.[31]
Poison traps
Four different types of trap, including container traps, can poison the hero and sometimes other monsters:[32]
- Container traps can release noxious gas which abuses constitution, and will deal damage with a 1⁄3 chance of lowering strength, a 1⁄15 chance of being fatal and otherwise dealing 6–15 damage.[33] Poison resistance prevents instadeath and blocks damage to HP or attributes, and there is a luck-dependent chance of the gas blowing away before it can do any harm.[34][35]
- Container traps can also fire a poisoned needle which abuses constitution, and will deal damage with a 1⁄2 chance of lowering constitution, a 1⁄10 chance of being fatal and otherwise dealing 6–15 damage.[36] Poison resistance prevents instadeath and blocks damage to HP or attributes, and there is a luck-dependent chance of the needle missing.[34][37]
- Dart traps that activate and fire a dart at a hero or monster have a 1⁄6 chance of the dart being poisoned[38][39][40][41]—as with thrown poisoned darts, they have a further 1⁄2 chance of lowering constitution and a 1⁄10 chance of being deadly, and otherwise deal up to 6 extra points of damage.[26] Poison resistance blocks all of these effects.
- Spiked pits have a 1⁄6 chance of poisoning the victim each time they fall into one, including falling into the same pit repeatedly[42]—the poison from the spikes has a further 1⁄2 chance of lowering strength and a 1⁄8 chance of being fatal, and otherwise deals 6–15 damage, with strength loss occurring if life saving triggers in response to fatal poisoning or HP damage.[43] Poison resistance blocks all of these effects.
Strategy
The threat of an instant and unceremonious defeat to a poisoned trap or weapon means that poison resistance is a highly critical property to obtain for any hero at the beginning stages of any NetHack game, to the point that certain roles have more leeway in how far they can explore the early dungeon versus others.
The Barbarian is one of the most clear examples of this, being a strong melee role that starts with poison resistance, while Monks gain the property at experience level 3, and can easily gain the required experience with their martial arts. Orcish heroes in roles that lack poison resistance have somewhat better survival chances early on compared to other races in that same role, though this is also subject to tradeoffs elsewhere (such as lower strength caps and mental stats). Healers start with poison resistance, and while this does give them something of an edge over other casting roles, they are also generally more fragile and restricted in several other aspects.
Intrinsic poison resistance is granted by eating any of a large variety of corpses—as indicated by the list of poisonous monsters in the table below, many of these corpses are poisonous themselves, and loss of strength and carrying capacity can spell a hero's doom early on, so it is not advisable to eat them without some way of avoiding or curing strength loss. Even monsters that have non-poisonous corpses which grant the intrinsic, such as quasits and puddings, can use poisonous attacks or prove hazardous in other ways—tins and corpses of quivering blobs, naga hatchlings, and red and brown molds are among the sources that are safest to eat. See the poison resistance article for a comprehensive list of monsters that grant poison resistance when eaten.
Precautions
There are many precautions a hero can take to make poison less perilous to deal with. For poisonous corpses, applying a tinning kit to a poisonous corpse will remove the risk of poisoning, a worn ring of sustain ability will prevent attribute damage from eating the corpses, and applying a non-cursed unicorn horn, quaffing a potion of restore ability or successfully casting the restore ability spell can repair attribute damage. If all else fails, successful prayer can also potentially restore attributes: a hero being overtaxed while having lost at least four points of strength is considered a major trouble, while having any reduced attributes at all is a minor trouble.
For dealing with other sources of poison, wearing extrinsic sources of poison resistance such as an amulet versus poison is ideal to both significantly reduce poison damage and widen the amount of safely edible corpses available, including ones that you can obtain the intrinsic from—even once you obtain the intrinsic, it may be worth keeping an extrinsic source or two in case you lose it to a throne or a gremlin attack.
If you lack even an informally known source of poison resistance, high magic cancellation can protect against poisonous melee attacks, and it is already wise to avoid randomly using unknown scrolls and potions to minimize the odds of quaffing a potion of sickness or randomly reading a scroll of stinking cloud; in the latter case, the scroll can be discharged harmlessly by selecting a far away square out of range. Dip-testing using projectiles such as arrows and darts can reveal the identity of a potion of sickness without the risk of quaffing it, though this will use up the potion in the process, and some other potions such as oil can also be used up this way. While dart traps and spiked pits can be difficult to find without tripping them, early dart traps in particular are often marked by corpses of their previous victims, and other monsters that walk into the traps can serve as indicators, especially if the trap killed them.
The following information pertains to an upcoming version (NetHack 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.
Unicorn horns can no longer restore strength, and praying as described here does not work.Statistics
The table below is a quick review of general poison sources and which ones can be deadly:
| Source | Chance of extra damage | Chance of deadly poison | Chance of stat damage |
|---|---|---|---|
| Monster melee attack | 1 in 8 successful attacks that are not blocked by magic cancellation | 1 in 30 poisoned attacks | 1 in 6 chance of damaging strength, dexterity or constitution |
| Monster ranged weapon | always | 1 in 30 successful hits | 4 in 5 chance of damaging strength |
| Poisoned dart trap | 1 in 6 | 1 in 10 poisoned hits | 1 in 2 chance of damaging constitution |
| Poisoned spiked pit | 1 in 6 | 1 in 8 'poisoned' falls | 5 in 8 chance of damaging strength |
| Noxious gas container trap | depends on luck | 1 in 15 chance | 1 in 3 chance of damaging strength |
| Poisoned needle container trap | depends on luck | 1 in 10 chance | 1 in 2 chance of damaging constitution |
| Poison blast attack from an iron golem or green dragon | always | 1 in 15 chance | 1 in 3 chance of damaging dexterity |
| Poisonous corpse | 4 in 5 | none | always damages strength, deals d15 HP damage |
List of poisonous monsters
This more detailed table lists monsters that are either poisonous or have poisonous attacks, and whether they also possess poison resistance, grant poison resistance, or have some combination of the aforementioned traits:
| Monster name and glyph | Poison attacks? | Poisonous corpse? | Poison resistance? | Grants intrinsics? | ExpandNotes |
|---|
History
Poison has been present in the game since Hack 1.21 and Hack for PDP-11, which are based on Jay Fenlason's Hack, and also appears in Hack 1.0. From these versions to NetHack 2.3e, strength is the hero's sole attribute and thus the only one that poison can affect—the other five attributes are introduced in NetHack 3.0.0.
Variants
A user has suggested improving this page or section as follows:
"Renovate entire section."
SLASH’EM
In SLASH'EM, you can also poison weapons by dipping them in a toilet.
UnNetHack
In UnNetHack, the chance of an instadeath from poison is replaced with a "very toxic" poison that damages max HP and does strength damage, reducing the chance or frustrating YASD (though it is still nearly always fatal to low level characters). Other detriments of being poisoned remain the same.
FIQHack
FIQHack also eliminates poison instadeath and replaces it with permanent attribute damage, which cannot be fixed via potion or unicorn horn. Additionally, poison resistance only halves poison damage, ensuring that it is never completely safe to eat a poisonous corpse; chances of attribute reduction are also lowered to one third of the time, and the attribute loss itself is reduced by a third.
Since poison resistance only partially protects you in FIQHack, the amulet versus poison and the ring of poison resistance are even more useful as they completely protect you from the effects of poison.
References
- Jump up ↑ src/attrib.c in NetHack 3.6.7, line 273: poisoned() function
- Jump up ↑ src/attrib.c in NetHack 3.6.7, line 312
- Jump up ↑ src/mhitu.c in NetHack 3.6.7, line 113
- Jump up ↑ src/attrib.c in NetHack 3.6.7, line 292
- Jump up ↑ src/mhitu.c in NetHack 3.6.7, line 1126
- Jump up ↑ src/mhitu.c in NetHack 3.6.7, line 1129
- Jump up ↑ src/mhitu.c in NetHack 3.6.7, line 1132
- Jump up ↑ src/mhitu.c in NetHack 3.6.7, line 1136
- Jump up ↑ src/mhitu.c in NetHack 3.6.7, line 1139
- Jump up ↑ src/attrib.c in NetHack 3.6.7, line 295
- Jump up ↑ src/zap.c in NetHack 3.6.7, line 3870
- Jump up ↑ src/uhitm.c in NetHack 3.6.7, line 1887
- Jump up ↑ src/zap.c in NetHack 3.6.7, line 4562
- Jump up ↑ src/region.c in NetHack 3.6.7, line 979
- Jump up ↑ include/monflag.c in NetHack 3.6.7, line 98
- Jump up ↑ src/eat.c in NetHack 3.6.7, line 1649
- Jump up ↑ src/objects.c in NetHack 3.6.7, line 113-L130
- Jump up ↑ include/obj.h in NetHack 3.6.7, line 201: specified ranged covers all weapons from arrows to shuriken in objects.c[17]
- Jump up ↑ src/mkobj.c in NetHack 3.6.7, line 813
- Jump up ↑ src/potion.c in NetHack 3.6.7, line 2114
- Jump up ↑ src/u_init.c in NetHack 3.6.7, line 1090
- Jump up ↑ src/makemon.c in NetHack 3.6.7, line 157
- Jump up ↑ src/mthrowu.c in NetHack 3.6.7, line 285
- Jump up ↑ src/mthrowu.c in NetHack 3.6.7, line 628
- Jump up ↑ src/uhitm.c in NetHack 3.6.7, line 1135
- ↑ Jump up to: 26.0 26.1 src/mthrowu.c in NetHack 3.6.7, line 374
- Jump up ↑ src/uhitm.c in NetHack 3.6.7, line 1117
- Jump up ↑ src/uhitm.c in NetHack 3.6.7, line 1122
- Jump up ↑ src/potion.c in NetHack 3.6.7, line 1125
- Jump up ↑ src/potion.c in NetHack 3.6.7, line 2125
- Jump up ↑ src/eat.c in NetHack 3.6.7, line 2579
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 4797
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 4905
- ↑ Jump up to: 34.0 34.1 src/trap.c in NetHack 3.6.7, line 4814
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 4837
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 4905
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 4831
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 997
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 1002
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 2239
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 3989
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 1261
- Jump up ↑ src/trap.c in NetHack 3.6.7, line 1268
