Revisiting Poison

Last Updated: 171230, 200616

With perhaps the exception of level drain, little is feared more than poison, with a character’s destiny hanging on a single saving throw. Yet the odds of avoiding poison are low. 10% of all monsters in the MM are poisonous. In particular, many of the early monsters (spiders, snakes, centipedes) are poisonous. Appendix A suggests that 35% of all treasure is guarded by poison. While Appendix G suggests that only 7% of the traps include poison, that frequency in modules is much higher; there’s likely not a module written without the ubiquitous poison needle trap. Roughly 15% of all summoned monsters are poisonous.

Indeed, poison is powerful enough that the DMG suggests that character use is undesirable because it makes play less interesting. Non-evil clerics and paladins can’t use poison at all (paladins won’t even adventure with a group that uses poison). Assassins can’t create poison until 9th level, and then only after months of study at a cost of ~60,000 gp (even then a dose of poison takes a week to construct for another 200-1,200 gp).

Despite extensive notes on assassins’ use of poison, the DMG encourages sanctions for character use of poisons (if not disallowed for characters entirely!). Thieves can set poison traps, but can’t wear any protective hand gear in case of failure setting the trap and poisoning themselves. Envenoming a weapon is described as “difficult,” with one recommendation checking if the PCs nick themselves when they handle poisoned weapons. Even then poison on a blade wears off after only two blows. Character types other than assassin automatically grant a further +2 save to poison when striking with a poisoned weapon due to their inability to apply it effectively (and even assassins grant +1). Assassins using a poisoned weapon further risk their poison being noticed – a cumulative 10% per round. And if any onlooker spots the poison, they will attack, call the watch, or both! A further recommendation is that characters discovered with poison be killed and their ashes scattered (causing permanent death, removing any hope of being raised from the dead)!

In this universe of limiting poison usage for players that the monsters get relatively free reign. While real-world neurotoxins take 5-10 minutes, most monster poisons in AD&D are instantaneous all-or-nothing; the character either makes the saving throw or dies immediately (“within a minute or so”). In a combat scenario, that further increases the odds that other characters will be attacked and poisoned in turn, as the poisonous attacks turn elsewhere.

Once poisoned, a character has limited recourse. While holy water will “slow the onset of poison” (DMG Appendix), the specifics aren’t defined. The DSG Healing proficiency declares efficacy only when used “immediately” after poison, even though poisoned characters die “immediately.” WSG defines the efficacy of the Healing proficiency as “beginning in the same round that the poisoning occurs,” almost impossible within the constraints of the initiative system which doesn’t permit “within a round.” It’s improbable that the intent of those proficiencies was working only when the party is surprised, loses Initiative, or has declared they’re going to treat someone for poison who hasn’t been poisoned yet!

Monks aren’t immune to poison until 11th level. Barbarians have only a 10% chance of effecting a cure (50% + CON Score if the poison is known). The druid Slow Poison includes only a 5% chance / level to know a herbal antidote (and then only if the poison is made from a plant).

Even with a cleric, there’s not much a party can do. Normal healing doesn’t cure poison. Purify Food/Water will remove the poison from a substance, but not after the poison has affected a character. Slow Poison will take effect only if cast within 1 turn/cleric’s level after the character is poisoned, so the spell can be cast only once (twice if timing things to eke out every moment) before time runs out for the unfortunate character. The recipient of Slow Poison loses 1 hit point per turn (to a minimum of 1 hit point) for the duration of the spell (6 turns/level of the caster). However, unless the party is within a few hours of a 7th level cleric with Neutralize Poison (at the cost of 1,000 gp), Slow Poison won’t make any difference; the spell will wear off and the PC will still die.

Neutralize Poison is, as written, almost worthless by itself. Neutralize Poison takes 7 segments to cast, hard to complete part way through a round. Characters will already have failed their saving throw and be dead. If a party cleric needs to pray for Neutralize Poison, it will take almost seven hours, far longer than any hope from of Slow Poison.

Magic items are more likely to poison than to cure, as there are few magic items to aid a poisoned character. 3% of potions are poison. The Staff of the Serpent has a poisonous strike, and the Dagger of Venom will permit use of poison without observation. The Cloak of Poisonousness just kills characters. If applied in advance, Sweet Water will negate a Potion of Poison, but destroys other potions as well, negating any prophylactic use. The Periapt of Proof Against Poison only decreases the chances of being poisoned. The only magical cure available to PCs is Keoghtom’s Ointment, encountered .02% of the time.

Holy Water

The Appendix of the DMG indicates that holy water can slow the effects of poisons, with no further detail. The only defined effects of holy water are slowing the onset of lycanthropy or becoming undead for 1-4 turns. One extrapolation therefore would be that holy water delays the onset of poison by a similar duration. Dragon #081 suggests that holy water acts as Slow Poison with the duration as cast by a 1st-level cleric (6 turns/1 hour), where the first dose of holy water must be administered within 1 turn minus 2-5 segments of the time of poisoning to have the desired effect. Effects of multiple applications of holy water are cumulative with respect to duration; a double dose extends the effect for 2 consecutive hours (as long as the second dose is administered before the first one wears off).

Cleaning up the Timing

Death from poison takes effect immediately (defined as “a minute or so”) but clearly the precise timing matters. Time to use proficiencies, cast Neutralize Poison, drink holy water, or apply other remedies, and the party could be engaged in combat. Exactly how long does it take to die of poison?

Slow Poison, an only 2nd level spell, causes a supposedly dead character to have life restored if cast within a number of turns equal to the level of the cleric. The implication on “supposedly” is that poisoned characters aren’t actually dead, just close enough that the difference can’t be discerned. If the character is indeed not truly dead, Neutralize Poison should likely work within the same window (1 turn / caster level), although the two spells are not the same (Slow Poison is necromantic but Neutralize Poison is Alteration). Extending that logic further, spells affecting poison should take effect if used within 1 turn/ caster level (magic items are defined as cast by a 12th level caster). Since holy water works within a turn, it follows that the proficiencies be defined in a similar manner. That timing is then consistent with the timing of zero hit points when poisoned, and death one turn later at -10.

Yet the ability to cure poison with no negative effects is in and of itself inconsistent. Slow Poison slows the damage to 1 hit point / turn, but there’s no baseline of damage from “instant” poisons.

Death Isn’t Instant?

Poisons are divided into monster poisons and those purchased (or concocted). Monster poisons are an all-or-nothing immediate affair. Yet the DMG lists purchased poisons with a variety of onset times, and damage and/or death depending on the save. Most of them cause damage instead of immediate death. Why do some poison potions do damage that can be healed, yet normal healing doesn’t help a character affected by an immediate poison? Poison causes physiological damage (the cause of death). When a character is poisoned why don’t hit points factor in? While healing can’t remove the poison, healing should be able to repair the damage caused.

Slow Poison’s effect implies that even immediate poison does physical damage that occurs over time, given that Slow Poison reduces that rate to 1 hit point/turn. Inferences from Slow Poison are that actual death from poison takes a while. What if we try to tease that apart? What if we consider the damage effects of poison?

If the 2nd level Slow Poison brings character back to life it would be disproportionately powerful. It’s clearly 2nd level not for balance, but because the spell is necessary with “immediate” poison. If death is defined as “in a round or so,” what happens during that time? Poison effects aren’t specified in the time just before death.

One way to address the conundrums of hit points and immediacy is to modify the poison mechanic to incorporate hit points. If the character fails their save, treat all poisons as ongoing damage, losing hit points until death. For those poisons that do a fixed amount of damage, that damage will accrue over time. For those poisons that cause immediate death, the PC will arrive there when they run out of hit points, collapsing at 0 hit points and dying at –10. Using hit points also resolves a separate question of what happens when a PC is poisoned twice—the rate doubles. Higher level characters appropriately survive longer when poisoned.

With the incorporation of hit points, death is delayed, yet the unaided result will be similar. An unaided PC will still perish before the party can typically reach external aid, yet survive long enough for the party to react. If Slow Poison is cast within a round or two, the PC’s hit point loss will only vary by a point or two. If the party has Neutralize Poison available (in whatever form) they’ll neutralize the poison, but as an alteration spell Neutralize Poison won’t heal the damage done. Neutralizing the poison doesn’t heal the damage, it just prevents further damage. Healing doesn’t remove poison, but can heal the damage. 1 hit point / round is fast enough it carries real risk, but slow enough for the party to do something about it. It also incorporates hit points, which provides another way to extend the PCs life while searching for recourse—healing.

The virulence of monster poisons varies, as suggested by bonuses (or penalties) to the saving throw. That can be represented by varying the amount of damage per round caused by poison. If the base amount of damage / round was 1, a saving throw bonus of +4 could reduce that to only 6 hit point/ turn, where a save penalty of -2 could increase damage to 12 hit points of damage / turn.

Normally PCs affected by poison are immediately incapacitated, yet using hit points to determine time of death doesn’t represent that effect. A solution would be using character Constitution: when the PC takes more poison damage than their Constitution, they’re incapacitated. Those so incapacitated would be disabled/unconscious for d3 turns.

So where does that leave us?

Revised Poison
Upon failing a save when poisoned, the PC loses 1 hit point/round (modified by save bonus). Slow Poison reduces that to 1 hit point/turn. While the damage inflicted by poison can be healed, the effects of the poison continue until the poison is neutralized or the character dies. A character is incapacitated when they take more damage from poison than their Constitution (or, of course, reach 0 hit points). Non-magical neutralization of poison (character abilities, proficiencies, holy water) must occur within a turn. Magical poison reduction can occur as long as the PC is alive.

The real failing I see is caused by the ongoing nature, now having to track ongoing damage per round (or per turn). The ability to heal the damage is also likely to drain the party’s ability to heal, potentially spending all of their healing in a mostly doomed attempt to keep the PC alive.

Appendix – MM Poisons

Note that many things require a Save versus poison. The below are those that appear to be actual poisons, roughly 10%(not by rarity)

MM, Giant ant: 0, d4/death

MM, Centipede: +4. non/death

MM, Couatl: 0, non/death

MM, Orcus: -4, non/death

MM, Baalzebu: 0, non/death

MM, Erinyes non/faint d6 rounds

MM, Geryon -4, non/death

MM, Green dragon: 0, non/death

MM, Eel, weed: 0, non/death

MM, Frog, poisonous: +4, non/death

MM, Golem, iron: 0, non/death

MM, Imp: 0, non/death

MM, Manticore: 0, non/death

MM, Medusa: 0, non/death

MM, Naga: 0, non/death

MM, Pseudodragon: 0, non/catalepsy

MM, Purple worm: 0, non/die

MM, Ray, pungi: 0, non/death

MM, Ray, sting: 0, non/paralyzed

MM, Scorpion: 0, non/death

MM, Snake: non or 3d6/death

MM, Spider: +2 to -2, non/death

MM, toad: 0, non/death

MM, Wasp: 0, non/paralysis and death

MM, Wyvern: 0, non/death


Author: Rick

A DM for *mumble* years, I've been playing AD&D since junior high. I've currently got two separate campaigns running, both in Mystara. I've been told when they handed out hobbies, I stood in the short lines. I actively cycle tour, kayak, play board games, read, develop home automation software, volunteer with the American Red Cross, and work on a never-ending stream of home repairs. In my wake I've left paintball, medieval full-contact combat (SCA), computer gaming, Heroclix, tablet weaving, and kite construction.

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