Given the new edition of Iron Kingdoms RPG, I realized that we have rules and abilities for resisting poisons, but no actual rules for poisons and toxins. So I thought until there was some official support for this I would just do what I do best.
Also worth noting is No Quarter #5, where old D20 material on subject is found.
First off lets just briefly review the rules for poisons.
The rules for poisons are buried in the IKRPG books on page 294 where they are first given with relation to the alchemical solution 'Antitoxin'. The special rules for Antitoxin is that after ingestion, the antitoxin takes effect;
'...the character immediately makes a PHY roll +5 against the toxin rating of the poison.'
Success indicated the antitoxin takes effect. It they fail, they get to roll again later, but with a +3 bonus. This of course all suggests that the basic rules for poisons is that a character gets to a PHY roll (so 2d6 + PHY) against the toxin rating of the poison. The 'Poison Resistance' ability means this roll is boosted.
So now we are left with some unknowns. First off what a typical toxin rating is? And then what are the effects of an untreated poison or toxin? Well lets start with the one toxin in the book that we do have, that is not lethal but in essence works the same way.
The Somnolence Elixir, on page 295 is a knock out drug. To resist it you need to make a PHY roll against a target of 16. So does not mean the 'toxin rating' of Somnolence Elixir is 16. Given an average 2d6 roll is 7, and that a typical PHY rating is around 5, then 16 is quite high, and so a person better able to resist it, or with a antitoxin can on average resist this drug.
Given all of the above then we assume an easy to resist toxin has a rating of 11, and difficult one is 16 or higher, and if higher an antitoxin is of course required.
This seems in keeping with other examples of similar toxins, poisons and chemicals. Laughing Gas, as featured in Full Metal Fridays, has a target number of 12 for PHY roll, in order to resist the effects. This also gives an example of how additional rolls per turn are made, and if a set number are passed then the toxin runs it's course. This just represents the natural immunity of a person and how their body fights the toxin over time.
No Quarter #46 gives the example of the Devil Rats. Devil Fever is contracted through their bites, and again calls on a PHY roll vs a 12. So while relatively easy to resist, if you fail the effects are bad. Additional PHY rolls are required vs a higher difficulty, aka toxin rating. Again a certain number need to be passed, or in this case failed, for it to move on to the need advanced stage of the fever.
Now what about effects?
The Somnolence Elixir causes a reduction in INT and PER is the character successfully resists it. A garrot for example, causes a reduction in PHY each turn of the grapple, and if the character drops to 0 PHY they pass out, and if it is maintained, then the character dies. Devil Fever starts dealing damage every hour, and so really poisons could do all manner of things, such as reducing attributes or dealing direct damage per turn, or per hour, and causing other effects like simply falling unconscious.
So No Quarter #5 had some rules for poisons and toxins but with D20 rules. So lets have a stab at updating them.
Made from various spores, it is a powder that if inhaled takes effect in 1 hour. A PHY roll vs 13 is required and if failed it causes -1 PHY, otherwise they shook off the toxin. After being poisoned make rolls every hour 3 rolls are failed the victim suffers 3d6 damage and -1 PHY, and must roll every hour after and take the same damage. If they pass 3 rolls they shake off the poison, and begin to regain PHY at
This is a truth serum, developed in Khador. The drug is swallowed or injected. It takes 1 hour to take effect. Given a PHY roll vs a toxin rating of 13. Failure leads to -1 INT, -1 STR, -1 PHY and (this will mean -2 Willpower). Make this roll once every half hour. If the target succeeds 3 rolls he has resisted and the drug is then out of his system, and he will being to recover his attributes This makes the character more susceptible to interrogation, less able to lie, and more susceptible to fear. It can be used once per hour if the target is resisting.
Black tar is used to lace drinks and it leads to the drinker being incapacitated. It also means for a few days the victim's urine is black and acrid. Black Tar is resisted with a PHY roll vs a toxin rating of 7. Each dose consumed in the last hour increases the toxin rating by 1. The victim falls asleep for D6+1 hours. The sleeper is only awakened by damage, in which case they must make a Willpower roll + 1 per damage they took, vs a target of 20.
A concoction of various poisons and cleaning fluid. PHY roll vs toxin rating of 11. Deals 2d6 damage. Roll each turn unless an appropriate antitoxin is used, such as that derived from the tatzylwurm.
Any feedback or modifications to these are welcome.