Poison

Version 0.31: This article may not be up to date for the latest stable release of Crawl.

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

Poison is one of the most common elemental forces you will encounter as you explore the Dungeon. It is most often encountered in the form of stings and bites of poisonous monsters, though it can also be inflicted through spells or venom.

Useful Info

Generally, being poisoned means gaining the Poison status effect. Its duration and damage per turn depends on its severity. Poison can be stacked; multiple instances of poison will increase the severity. For players, severity is displayed by the colour of the word "Pois" (going from yellow -> light red -> red). For monsters, you can view severity by examining it. In tiles mode, monster poison is represented by green drops ("extremely poisoned" = 3 drops = max poison).

In addition, some spells, like Sting, Poisonous Cloud, and Poison Arrow, deal poison impact damage. This is the same as any regular form of damage, but is resisted by poison resistance.

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.

Poison will continue to damage monsters outside line of sight, however, it won't do anything to monsters on a different floor.

Sources

Players (and monsters) can apply poison via the following methods:

• Certain forms of Alchemy magic
• Venom-branded melee weapons
• Staff of alchemy or Staff of Olgreb
• Poisoned and curare-tipped darts
• Nagas have an innate Spit Poison ability.

Poison Types

In addition to venom-branded weapons, monsters can have innate poisonous attacks. There are two types: 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

Venom-branded weapons work differently. When monsters attack players, venom has a 75% chance to add 6-13 poison damage, plus a random amount ranging from 0 to 1.5x physical damage done. When players attack monsters, it inflicts 1 + (4 + 1d8 + 1d<1.5 * dam>)/7 "stacks" of poison to the enemy.

Poison Resistance

Players and monsters can have a single level of poison resistance (rPois+) or complete immunity (rPois∞, represented in the code as rPois+++). rPois+ doesn't stack, so an Octopode can't wear 3 rings to gain immunity.

Poison resistance grants the following:

• 66% (2/3) chance to prevent the poison status from most sources.
• 66% chance to block the slow effect of curare, the slow/paralysis of hornets, and hostile Alistair's Intoxication.
• -66% poison impact damage.
• Full immunity to poisonous clouds, Mercury Vapours' poison, and Mephitic Cloud.

In addition, rPois monsters (not players) are fully immune to curare. For most effects, poison resistance does not reduce the amount of poison status directly, only the chance that you get poisoned.

Poison immune creatures can't be poisoned and do not take poison impact damage.

Note that Sting, Poison Arrow, and Eringya's Noxious Bog deal 70% poison impact and 30% physical damage, so even poison immune creatures will take some damage from these spells. Poison resistant creatures take a total of 53% damage from these spells.

Poison Vulnerability

Some monsters (particularly insects and spiders) are vulnerable to poison, taking twice as much damage from poison attacks, and doubling the amount of poisoning received. You can also gain vulnerability from the Virulence spell.

Any amount of rPois+ will negate vulnerability, causing you to take regular damage from poison. Poison immunity, of course, prevents poison vulnerability from doing anything.

Sources of resistance

You can acquire poison resistance from a number of sources:

• Poison Resistance mutation
• Slimy Green Scales 3
• 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
• 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), gargoyle, or djinni
• Players in Death Form, Statue Form, or Storm Form are immune to poison while in one of those forms. Poison won't count down during these transformations, however, so if you transform while poisoned you'll be just as poisoned when they end.
• Wielding the Staff of Olgreb. Unlike the transformations above, the poison status will count down (harmlessly) while you wield it.
• Zin's Vitalisation ability. Poison counts down harmlessly.

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

• Healing yourself through other means will not cure the condition, but may give you the HP you need to wait it out.

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 you worship Cheibriados (any piety level, not under penance), 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

Monster poison is measured by the number of "stacks" of poison it has. Each source of poison will inflict one or multiple stacks. There is a maximum of 4 stacks, after which a monster is "as sick as possible".

Damage per turn is determined by the number of stacks of poison a monster has:

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

This damage is then modified by poison vulnerability (but not resistance).

Poison damage per 1.0 turn (monsters)

# Stacks	Normal			Vulnerable		Description
	Dmg.	Avg.		Dmg.	Avg.
1	0-2	0.75		1-3	1.75	Poisoned
2	0-3	1		1-6	3	Very poisoned
3	0-4	1.25		1-9	4.25	Very poisoned
4	1-6	2.5		2-13	6.5	Extremely poisoned

History

• Prior to 0.27, poison damaged players much more slowly. Overall damage was the same, but damage/turn was weaker.
• 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, poison resistance allowed you to eat poisoned chunks, which have been 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