Poison

Version 0.25: 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, and by yellow highlighting on your health bar). The duration of this condition and the amount of damage it deals per turn 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. In addition, part of your health bar will turn yellow to indicate the total damage that the poison will eventually do. 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. The staff of poison and staff of Olgreb have a poisonous melee attack that is dependent on your skill in Poison Magic and Evocations. Poisoned darts can be Thrown for a ranged poison attack.

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.

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

Needle traps may inflict the condition, as will being affected by miasma.

Poison Types

Monsters can have two types of poison attacks: normal and strong poison. Both have a 1/3 chance to trigger on each hit.

• Normal poison will poison the player for a random amount between 2 and 4 times the monster's HD
• Strong poison will instead poison for 3.67-6.5 times the monster's HD

Poison-branded weapons have a 3 in 4 chance to trigger, and do not depend on HD. Instead, they add poison damage equal to 6-13 plus a random amount from 0 to 1.5x the damage done.

Poison Resistance

Players and monsters can have a single level of rPois or, less commonly, complete immunity (which is represented as three levels of resistance in the game's code). Having multiple sources of poison resistance is no more effective than having a single one, though: an Octopode can't wear three rings to become immune.

Resistance confers immunity to Mephitic Cloud and Alistair's Intoxication, and gives a 2 in 3 chance of shrugging off poison at the time that it is applied. Complete immunity 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.

You can acquire poison resistance from a number of sources:

• Poison Resistance mutation
• The third rank of the Slimy Green Scales
• Swamp dragon scales
• Gold dragon scales
• Armour of poison resistance
• Staff of poison
• Ring of poison resistance
• Tiamat's dragonskin cloak (50% chance per attack)
• Randarts
• Potion of resistance
• Tree form from a potion of lignification
• Ice Form or Dragon Form
• Being a naga or green draconian

Additionally, there are a few ways to become totally immune:

• Being an undead race (mummy, ghoul, or bloodless vampire)
• Being a gargoyle
• Casting Necromutation or Statue Form renders you temporarily immune to poison. Poison won't count down during these transformations, however, so if you cast them while poisoned you'll be just as poisoned when they end.
• Wielding the Staff of Olgreb. Unlike the transmutations above, the poison status will count down (harmlessly) while you wield it.

Some things other than resistance can help against poison as well:

• Zin's Vitalisation ability prevents the status effect, but 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 will completely negate up to 25 points of poison damage.
• 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 amount of poisoning 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.
• 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, increasing the eventual damage. Different damage formulas are used for players and monsters:

Player Formula

• For players, poisoning has a predetermined total damage, and will deal a portion of that damage each turn. The more poisoned you are, the more damage per turn this will do and the longer it will last. The total amount of damage it will eventually do is displayed as a yellow-highlighted section of the health bar.

• If your Cheibriados piety is at * or above (slowed/strengthened metabolism), poisoning will only do 2/3rds as much damage per aut but will last 1.5 times as long. This effectively spreads the damage out over a longer time, which gives you more time to regenerate health.

Monster Formula

poisonval is the 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.

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 0.18, monsters with poison resistance were immune to the poison status effect, except from the staff of poison and poison arrow.
• 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 0.14, poison's damage over time was randomized instead of being a fixed value.
• 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