Poison

Version 0.17: This article may not be up to date for the latest stable release of Crawl.

This page is about the effect. For the spell school and skill see Poison Magic.

Poison is one of the most common elemental forces you will encounter as you explore the Dungeon. Both players and monsters can take advantage of poison through spells or specially branded weapons, though it is most commonly encountered in the form of the stings and bites of poisonous monsters.

Poison Damage

Generally, poison damage occurs over time whenever something suffers from the Poison condition (indicated by the word Pois on your status). The duration of this condition and the amount of damage it deals per turn is somewhat randomized, but depends heavily upon the severity of the poison. This is displayed by the color of the word "Pois" in your status: yellow lettering means mild poison, pink is medium, and red is severe. Be cautious in areas with poisonous monsters, as the poison condition can be stacked; getting hit multiple times from a poisonous enemy can result in severe poisoning if you're careless.

While even low-level characters can usually survive mild poisoning, severe cases can deal tremendous amounts of damage over time. In any case, it is almost always best to rest and avoid combat until the poison has run its course, perhaps on a cleared floor to avoid wandering monsters.

Alternatively, some spells and abilities deal poison damage directly, causing an immediate drop in HP. These attacks usually also inflict the poison condition, making them exceedingly dangerous for characters without appropriate defenses.

Try to avoid being both sick and poisoned, as your natural regeneration contributes much to your chances of surviving poison. This is also why poison is more dangerous to low-level characters than high-level ones -- at low levels, your regeneration rate may not be fast enough to keep up with poison.

Poison Sources

It is relatively easy for characters to gain access to sources of poison damage. Characters who specialize in weapons that strike quickly can benefit from venom-branded weapons, which inflict the poison condition on top of their normal physical damage. Ranged weapon-users can instead use poisoned missiles, which function identically. Both of these effects are stackable for more lethal results. The staff of poison and staff of Olgreb have a poisonous melee attack that is dependent on your skill in Poison Magic and that can potentially affect poison-resistant creatures.

The Poison Magic school is also available to venom mages or any character with Spellcasting capabilities and an appropriate book. This school is devoted almost entirely to dealing poison damage, though it also contains some spells for inflicting confusion and a handy poison remedy for yourself.

Nagas have an innate Spit Poison ability which inflicts significant physical and poison damage.

Characters can also be poisoned in a number of unorthodox ways. Characters quaffing unidentified potions may accidentally drink a potion of poison or potion of strong poison. Needle traps and pressure plates may inflict the condition, as will being affected by miasma.

Worshipers of the Shining One should avoid inflicting poison, as he is offended by such dishonorable tactics.

Poison Types

There are four types of poison: regular, medium, strong, and nasty.

• Regular poison has a 25% chance of giving the defender one level of poison on a successful attack (5% if the attack does less than 2 points of damage).
• Medium poison has a 33% chance of poisoning the defender (7% if the attack did less than 2 points of damage) for 1d3 levels of poison.
• Strong poison has a 33% chance of poisoning the defender (7% if the attack did less than 2 points of damage) for 2d5+1 levels of poison. If the defender is natural or a plant and has 1 or 2 levels of poison resistance, it will take 1d3 levels of poison.
• Nasty poison always imparts 2 levels of poison to any creatures that are not immune or resistant.

Monsters receive half the above levels of poison, rounded down (but never less than 1).

Poison Resistance

In 0.10, poison resistance was changed to have multiple levels, although this is not reflected on the player's resistances overview. Any level of resistance confers immunity to Poisonous and Mephitic Cloud, and gives players a 90% chance of shrugging off each level of poison at the time that it is applied. Three levels of poison resistance makes one impervious to the "poisoned" condition, although poison damage is only partly reduced (see below) and many poison attacks have a physical component as well.

Monsters with three levels of poison resistance are immune to all sources of poison damage and the poison condition. Monsters with one or two levels of resistance can potentially still become poisoned by strong or nasty poison.

You can acquire poison resistance from a number of sources:

• Poison Resistance mutation
• The third rank of the Slimy Green Scales
• Swamp dragon hide and swamp dragon armour
• Gold dragon hide and gold dragon armour
• Armour of poison resistance
• Staff of poison or staff of Olgreb
• Ring of poison resistance
• Tiamat's dragonskin cloak (50% chance per attack)
• Randarts
• Potion of resistance
• Ice Form or Dragon Form
• Being a naga, green draconian, or thirsty vampire (these species all have poison resistance)
• Being undead (mummy, ghoul, bloodless vampire, or through Necromutation) or artificial (gargoyle or through Statue Form) renders you completely immune to poison.
• Zin's Vitalisation ability prevents the status effect, but you can't eat poisoned chunks and you still take full damage from sources of direct poison damage like Poison Arrow or Poisonous Cloud. However, it does grant resistance to Venom Bolt and Sting.
• Deep dwarf damage shaving affects damage from poison, and may effectively negate all but the most severe poison conditions
• Healing yourself through other means will not cure the condition, but may give you the HP you need to wait it out.

Poison Vulnerability

Some monsters (particularly insects and spiders – and you, in Spider Form) are vulnerable to poison, taking twice as much damage from poison attacks, and doubling the number of poison levels received.

Damage Reduction

• Sting and Venom Bolt

Resistance Level	Damage Taken (Player)	Damage Taken (Monster)
-1	100%	150%
0	100%	100%
1	100% or 50%	50%
2	-	20%
3	50%	0%

• Poison Arrow

Resistance Level	Damage Taken (Player)	Damage Taken (Monster)
-1	135%	135%
0	100%	100%
1	65%	65%
2	-	44%
3	44%	30%

Curing Poison

Characters that lack poison resistance can still avoid the worst of its effects by curing the condition before it runs its course. The following options are available:

• Quaffing a potion of curing.
• Cure Poison
• Elyvilon's Purification ability

Poisoned Condition

Poison attacks frequently result in a monster or player having the "poisoned" condition. While poisoned, a creature will take an amount of damage proportional to the degree to which it is poisoned. Each dose of poison "stacks" with previous ones, up to a maximum of 40 levels of poison for players. Different damage formulas are used for players and monsters:

Player Formula

• Each turn, you have a poison_level in 5 chance of taking damage from poison; at 5+ levels of poison, this is automatic. The damage is as follows:
  • If you have more than 10 levels of poisoning, if 1d(poison_level) is greater than 8, you will take 1d10+4 damage.
  • If you have 5-10 levels of poisoning, there is a 50% chance you will take 2-3 points of damage.
  • Otherwise, you will take 1 point of damage.
• You also have a 1 in 8 chance of losing one level of poison each turn (1 in 3 if you have been reduced to 1 hp).
• If your Cheibriados piety is at * or above (slowed/strengthened metabolism), there is a 50% chance you will take no damage – but this will bypass the check to lose a level of poison as well. This effectively halves the damage per turn of poison but doubles its duration (which also gives you more time to regenerate health).

Monster Formula

poisonval = number of stacked poison statuses on the monster

• If poisonval >= 4, base damage is 1. Otherwise, base damage is 0.
• There is a 50% chance of an additional 1d(poisonval+1) damage.
• If the monster is vulnerable to poison, there is an additional 2d(poisonval) - 1 damage.

Source: mon-ench.cc

Poison damage taken each turn (monster only)

# stacked poison	Average (normal)	Average (vulnerable)	Min (normal)	Min (vulnerable)	Max (normal)	Max (vulnerable)
1	0.75	1.75	0	1	2	3
2	1	3	0	1	3	6
3	1.25	4.25	0	1	4	9
4	2.5	6.5	1	2	6	13
5	2.75	7.75	1	2	7	16
6	3	9	1	2	8	19
N	N/4 + 1.5	N * 5/4 + 1.5	1	2	N + 2	N * 3 + 1

History

Prior to 0.17, as an added benefit, poison resistance allowed you to eat poisoned chunks, which have been removed and replaced by inedible chunks.

Prior to 0.13, Statue Form only granted one level of poison resistance.

See Also

List of poison resistant monsters

List of poison vulnerable monsters