The Pathfinder rules for both poisons and crafting non-magic items are incomplete and need three fixes:
Fortunately, we can do these three things without changing any rules. That is why we are "finishing" the rules, instead of "making new rules".
Pathfinder includes three types of characters who specialize in using the Craft (Alchemy) skill to create poisons. Keeping the poison rules incomplete is a bit unfair to these three types of characters.
The Alchemist at third level can craft poisons twice as fast as usual. Even better, an Alchemist can discover "Sticky Poison" which allows a weapon to remain poisoned for a number of strikes equal to the Alchemist’s Intelligence modifier.
The Poisoner Rogue at third level is able to change the type of poisons. (Note that a more historically accurate name for this character class would be "Apothecarist". Apothecaries were where old ladies shopped for rat poison for the cellar, and where young ladies shopped for belladona for their eyes.)
Finally, the Master Alchemist feat allows any character to create any poisons ten times as quickly, multiple doses at a time.
Poisons help close the power gap between warriors and wizards. Warriors become more powerful because poisoned weapons can do more hit point damage, often for several strikes (obviously the increase in weapon damage will be most dramatic for characters that use the two-weapon fighting style or the similar archery feats providing multiple attacks). Wizards become less powerful because they typically have weak Fortitude saving throws, so a single poisoned arrow or thrown vial of knock-out gas could knock them unconscious until an ally shakes them awake.
Poisons help make intelligent opponents more interesting. Any group of evil folk with third-level members could use poisons effectively in a variety of ways.
Consider a sixth-level character who cares about poison creation. How much poison can this character create in a day?
We should clarify our assumptions. The character has the Master Alchemist feat and the Skill Focus (Craft (Alchemy)) feat. The character also has Craft (Alchemy) as a class skill and a high Intelligence modifier either naturally or through a magic item. The poison will be difficult to resist: a saving throw DC of 20.
First we determine the character's effective Craft (Alchemy) skill.
The base skill is probably about 14 (= 5 for INT mod + 6 ranks + 3 class skill). The description of the Craft skill tells us that masterwork tools provide a +2 circumstance bonus. A Cauldron of Brewing (3,000 gp) provides a +5 competence bonus. The Master Alchemist feat provides an untyped +2 bonus. Skill Focus (Craft (Alchemy)) provides an untyped +3 bonus. Finally, the character casts (or has an ally cast) Crafter's Fortune to provide +5 luck bonus. That is a total effective skill of 31.
Next we follow the weekly crafting progress formula: die roll × crafting DC × multiplier.
Our average die roll will be ten higher than our skill, so 41.
The base DC to create a poison is equal to the poison's saving throw DC, so 20. But any crafting can be done at a ten higher DC to speed up the process. So our crafting DC is 30.
Our character has no multiplier. (An Alchemist might have a multiplier of 2.) But the Master Alchemist feat provides a huge benefit: the formula measures gold piece value.
Our answer is that this character can craft 41 × 30 × 1 = 1,230 gp per week worth of poison. That is about 175 gp per day.
Note that crafting mundane items works quite differently than crafting magic items. The materials for mundane items cost only one-third the retail cost. There is no restriction requiring stopping for the day when one item is completed.
A huge problem with the table of sample poisons is that all inhaled-type poisons are more expensive than items for which the crafting rules were intended to apply.
But the Rogue Poisoner's special ability resolves this issue. It does not matter if a strict reading of the crafting rules says that it would take weeks to craft a single dose of an inhaled-type poisons. We should simply assume that all inhaled-type poisons are originally crafted as less expensive injury-type poisons and then modified by Rogue Poisoners with one hour's work. The high price reflects the black market status of the items rather than anything about crafting them directly.
For the same reason we can restrict our discussion to creating injury-type and contact-type poisons.
We have a new question. If we can craft 175gp of poison per day, what kind of useful poisons can we make in a day or two?
Analyzing the table of sample poisons is not difficult, but describing the process would be really boring. The unsurprising result is that each of the seven aspects of a poison's description corresponds to a factor. To find the retail cost of the poison we simply multiply all seven of its factors.
Every poison has a frequency. How often does the victim need to make a Fortitude saving throw to avoid consequences? For injury-type poisons this is always "each round". For contact-type poisons this is usually "each minute". So poisons have a frequency factor:
It is odd that poisons that work more slowly are more expensive. Perhaps there is benefit in making an unseen getaway after poisoning the evil bandit lord?
(The extra price is not simply from the poison being a contact poison. Dragon Bile is indeed priced according to its "each round" frequency.)
Most injury-type poisons start working immediately. Most contact-type poisons have a delay of one frequency before they start working. So poisons also have an onset factor:
|delay 1 frequency||0.8|
It does make sense that a poison that starts promptly is slightly more expensive.
All poisons can be weathered with a series of successful saving throws. Naturally, a better poison has a higher DC. Poisons have a DC factor:
|14 or more||the DC|
The very lowest DCs (11 and 13) are so easy that these poisons have little retail value. They are useful for poisoning rats in the basement, not for combat.
All poisons stop working after a certain number of successful saving throws. Naturally, a better poison keeps working persistently. Thus poisons have a cure number factor:
|Number of Successes to Cure||Factor|
Assuming the target fails all of its saving throws, how many times does the poison have its effect? In other words, what is the maximum number of failures? Poisons have a maximum failures number factor:
|Maximum Number of Failures||Factor|
What happens when a saving throw is failed? Poisons can damage an ability score, cause hit point damage, or knock the victim unconscious. So poisons have a damage type factor:
|Dexterity or Strength||1|
|Constitution or Hit Points||2.5|
Some poisons have two damage types: the first saving throw threatens one kind of damage, and all subsequent saving throws threaten a second kind of damage. Use the larger damage type factor.
Poisons that cause unsconsciousness require at least two saving throws. The first threatens unconsciousness for as much time as one frequency--until the next saving throw. The second causes a longer period of unconsciousness, usually hours.
The rules do not say what happens to someone made unconscious by poison. I assume they wake up if they take damage or are shaken by an ally (the same as sleeping).
How much damage happens? We need a damage amount factor:
|1 to ability score||1|
|d2 to ability score||2|
|d3 to ability score||3|
|d4 to ability score||6|
|d6 to ability score||8|
|2d12 to Hit Points||0.87|
The factors described above do not exactly reproduce the costs of the official table of example poisons, but they are close.
Let's use the factors to invent three more poisons appropriate for combat use.
|Name||Frequency||Onset||DC||# to Cure||Max. Fails||Type||Amount||Cost|
|Knock-Out||rounds (1)||none (1)||20||one (1)||two (4)||unconscious (2)||unconscious (1)||160 gp|
|Affordably Feeling Feverish||rounds (1)||none (1)||20||two (2)||two (4)||STR (1)||d2 (2)||320 gp|
|Two Chances at HP||rounds (1)||none (1)||20||one (1)||two (4)||HP (2.5)||2d12 (0.87)||174 gp|
Let's also create a poison too weak for combat use.
|Name||Frequency||Onset||DC||# to Cure||Max. Fails||Type||Amount||Cost|
|Rat Poison||rounds (1)||delay one frequency (0.8)||11 (4)||one (1)||two (4)||HP (2.5)||2d12 (0.87)||28 gp|
Time for our third question. Are our new poisons fairly priced?
Unsurprisingly, the "Rat Poison" is too expensive for most people in the Pathfinder setting. It costs about a month's wages for a middle-class person.
The Gamemastery book says a PC living in a town with "average" lifestyle spends 10 gold pieces per month on food and board. This probably means most crafters and merchants earn about three times that, since PCs generally do not support a family. So crafters about earn 30 gold pieces each month. A gold piece is probably a daily profit for the middle-class workers of the Pathfinder world. This is consistent with the statement in the Craft rules that "You can practice your trade and make a decent living, earning about half your check result in gold pieces per week of dedicated work."
But the prices for equipment are already wacky when common folk are considered. That old ladies cannot afford to visit the apothecary for rat poison is unrealistic. But ten feet of chain, quilting needles, or an empty chest also cost about one month's wages. (This must be why Pathfinder towns have so many taverns: retired ladies can afford to eat and drink lots but not sew quilts.)
True, 2d12 damage is exessive for normal rats. But cellars in Pathfinder often have big rats.
The "Knock-Out" poison costs 160 gp and is simply a version of Drow Poison with the DC increased to 20. A comparable magic item would be a scroll of Deep Slumber (375 gp).
So the poison costs only 43% as much as the scroll. But the spell automatically hits and can affect more than one target. That seems a fair trade.
Remember that a knock-out type poison works better against spellcasters (with a high Will saving throw) than the spell, but worse against warriors and animals (with a high Fortitude saving throw). That also seems fair. It is better for game balance when the heroes and their opponents can have both options available.
The "Affordably Feeling Feverish" poison costs 320 gp. It has less duration than Medium Spider Venom or Large Scorpion Venom, but one successful saving throw does not totally cure it. Up to 4 Strength damage is slightly weaker than a scroll of Ray of Enfeeblement (25 gp).
In this case the poison is much more expensive. The scroll costs only 8% as much. But if the poison is applied by an Alchemist who knows the Sticky Poison discovery, the ability damage could happen five times (as opposed to unconsciousness, for which being out cold "again" does nothing). So the difference is significant but might be necessary for game balance.
The "Two Chances at HP" poison costs 174 gp and might do 4d12 damage. A slightly stronger magic item for comparison is a pair of scrolls of Lightning Bolt that each do 5d6 damage (375 gp × 2 = 750 gp).
The poison costs only 23% as much. On one hand, the spells automatically hit, and successful Reflex saves still do half damage. On the other hand, an Alchemist who knows the Sticky Poison discovery could make the poison work five times.
Cheap additional HP damage is why poisons can be a huge game-changer.
On average, how much damage does a 6th level Fighter using the two-weapon fighting style do when all four attacks hit?
18 (d8 weapon damage, 4×) + 20 (STR modifier of 5, 4×) + 16 (Power Attack 4, 4×) + 8 (Weapon Specializations 2, 4×) + 4 (Weapon Training 1, 4×) = 66 damage
If an Alchemist with the Sticky Poison discovery applied a 2d12 HP damage poison to all four attacks, that average damage would increase by 2d12 × 4 = 26. That is a 40% increase!
On average, how much damage does a 13th level Fighter using the two-weapon fighting style do when all six attacks hit?
27 (d8 weapon damage, 6×) + 30 (STR modifier of 5, 6×) + 48 (Power Attack 8, 6×) + 24 (Weapon Specializations 4, 6×) + 18 (Weapon Trainings 3, 6×) + 9 (Two-Weapon Rend) = 156 damage
If an Alchemist with the Sticky Poison discovery applied a 2d12 HP damage poison to all six attacks, that average damage would increase by 2d12 × 6 = 78. That is a 50% increase!
Of course, for all that extra HP damage to happen the target needs to fail many Fortitude saving throws. So not only will many combats will be quicker, but also enemies with a high Fortitude saving throw become comparably tougher. (Just what Pathfinder's setting needs: more owlbears.)
Most sizeable groups of urban crinimals or highway bandits will probably poison their weapons. After all, once their Alchemist applies the poison it will stay potent forever (until the blade is used several times). Since most criminals and bandits intimidate their victims while avoiding actual combat, the group's monthly expense for poison is probably very small compared to their income.
Perhaps even less intelligent foes such as giants and trolls use poison. We have seen that even with a zero Intelligence modifier the right feats and magic cauldron allow an effective Craft (Alchemy) skill above 30--sufficient to quickly craft any poison of DC 20.