all listed items must have a direct in game reference. (saying an object is made of .Chitin, scales ect. is acceptable)
Side bars and module/adventure references count.
No class discussion. except favored enemy or favored terrain. wild shapes and beast companion. ok.
Familiar alternates welcome.
wild shapes and beast companions ok if they provide a unique or rare ability.
No sidekick-companion npc talk. purchased pets ok.
poisons are ok but they must be non-wild shapes, not summoned, not on a crafted weapon, and not created via polymorph or similar spell/ability.
Try to use links if possible. [ monster] name [/ monster] : note. you should remove single space added before monster. Item and magicItem work the same way.
Some examples are.
Tressym. they are great for both alternate familiars and beast companions. detect invisibility and poisons are both too good. also understands common not just commands.
absolutely. as long as its a direct game use. I just don't want or need class comparisons.
I even want suggested rules. like ones that require "dms to make a call" for example we have solid poison harvesting rules but the number of times a creature can be harvested (if the creature is alive) is undefined/left up to the dm.
Purple worm has one of the most valuable and potent poisons in the game even one use is incredible.
flying snake poison is not an item but the game implies that it is and a unique one that bypasses saves.
I love crafting and give players a one time chance to take gold as “experience” instead of money. A couple of things.
1. As a DM I use narrative leveling (milestone leveling), so experience points aren’t a thing as such.
2. As a DM I use variant encumbrance, so weight is a huge issue (50 coins = 1 pound).
3. I hate the idea of a outdoor character needing to have money to make something, like needing 25 gp worth of materials to make a potion of healing.
All of this means that a character can take their cut of some treasure, say 100 gp, and keep 25 gp, but take the remaining 75 as XP! This 75 XP can be spent on a 1 XP per 1 gp ratio, using it to feed the raw material costs to craft things that they would be able to given their tools, supplies, proficiencies, and time.
I assume poisons don't fail unless the dm tells you they do. I assume part of the harvesting process is preservation.
there are some spots where healing potions going bad and (turn into poison) are referenced. (curse of strahd modules and the main adventure book) but that is usually unbelievably old ones or ones in areas with magical entropy.
I love crafting and give players a one time chance to take gold as “experience” instead of money. A couple of things.
1. As a DM I use narrative leveling (milestone leveling), so experience points aren’t a thing as such.
2. As a DM I use variant encumbrance, so weight is a huge issue (50 coins = 1 pound).
3. I hate the idea of a outdoor character needing to have money to make something, like needing 25 gp worth of materials to make a potion of healing.
All of this means that a character can take their cut of some treasure, say 100 gp, and keep 25 gp, but take the remaining 75 as XP! This 75 XP can be spent on a 1 XP per 1 gp ratio, using it to feed the raw material costs to craft things that they would be able to given their tools, supplies, proficiencies, and time.
Along that same line, it cost 25 gold worth of materials. There is nothing to say those materials aren't harvested from creatures or found as plants in the wilderness. they are just 25 gp worth of materials. How much effort is 25gp for an adventurer? I think roughly 2-5 days of collecting for skilled labor in xanathars.
dms should absolutely allow people to harvest and collect raw ingredients to by pass cost.
The only poisons in the core game with rules for "going bad" are PHB basic poison and the poison made by the poisoner feat. The standard poison rules were errated into the DMG, so the knowledge is public - here's the link: https://media.wizards.com/2018/dnd/downloads/DMG-Errata.pdf
Contact and injury poisons should last until delivered or washed off, after being applied to an object, and neither has rules for going bad, so they don't. Ingested and inhaled poisons don't have any rules for lasting until delivered or washed off, but I'm sure DM discretion applies - for example, we all know wine turns to vinegar, but it's not like arsenic will go bad in the can.
Something you'll need your DM to rule on is whether poisons are contact or injury - all monster poisons are written to use the contact rules (i.e. if you're bitten by a flying snake and are a raging barbarian, so you reduce the piercing damage to 0, you still take the poison damage - which definitionally means it's contact poison, not injury poison). This includes the already-mentioned Purple Worm poison - when a Purple Worm attacks you, it's contact, but if you harvest it and use it, it's injury. Looks like dndbeyond hasn't got purple worm poison in its item list, or I'd link it.
Carrion Crawler mucus is an incredibly useful poison which also highlights the difficulties here: when the monster uses it, it causes poison damage, but the harvested poison only causes poisoned and paralyzed. And there's no visible distinction between the crawler's rules and worm's rules, in terms of working out that the crawler's poison is contact in a PC's hands, but the worm poison changes to injury.
With respect to PC abilities, one of the best damaging poisons is flying snake poison, which is more powerful than giant toad poison. Both share the very hard to get quality of being able to crit, since there's no save to resist the poison damage. Theoretically Crawler poison would have this too, except that as I said, the DMG says harvested Crawler poison stops doing damage.
The only poison in the core game with rules for "going bad" are PHB [Tooltip Not Found] and the poison made by the poisoner feat. The standard poison rules were errated into the DMG, so the knowledge is public - here's the link: https://media.wizards.com/2018/dnd/downloads/DMG-Errata.pdf
Contact and injury poisons should last until delivered or washed off, after being applied to an object, and neither has rules for going bad, so they don't. Ingested and inhaled poisons don't have any rules for lasting until delivered or washed off, but I'm sure DM discretion applies - for example, we all know wine turns to vinegar, but it's not like arsenic will go bad in the can.
Something you'll need your DM to rule on is whether poisons are contact or injury - all monster poisons are written to use the contact rules (i.e. if you're bitten by a flying snake and are a raging barbarian, so you reduce the piercing damage to 0, you still take the poison damage - which definitionally means it's contact poison, not injury poison). This includes the already-mentioned Purple Worm poison - when a Purple Worm attacks you, it's contact, but if you harvest it and use it, it's injury. Let me see if the links will work for me. Purple Worm poison is contact, [Tooltip Not Found] is injury.
stench kow is clearly an inhaled poison. Stench. Any creature other than a stench kow that starts its turn within 5 feet of the stench kow must succeed on a DC 12 Constitution saving throw or be poisoned until the start of the creature’s next turn. On a successful saving throw, the creature is immune to the stench of all stench kows for 1 hour.
dretch is in the same boat but has a listed use number. basically like the spell slow.
Fetid Cloud (1/Day). A 10-foot radius of disgusting green gas extends out from the dretch. The gas spreads around corners, and its area is lightly obscured. It lasts for 1 minute or until a strong wind disperses it. Any creature that starts its turn in that area must succeed on a DC 11 Constitution saving throw or be poisoned until the start of its next turn. While poisoned in this way, the target can take either an action or a bonus action on its turn, not both, and can't take reactions.
I went on a little adventure looking through low-intelligence monsters to possibly hunt for poison, and I came across this beauty: assassin vine. That's clearly a contact vector (the vine doesn't even hit you - you get poisoned by touching it too much for too long), no-save 6d6 (21) poison, and on a CR 3 creature, to boot. I'd rather invest in assassin vine poison than purple worm poison.
Curse of strahd has Sangzor a "demon possessed? goat" that has pelt rules built into the module.
A character who wears Sangzor's pelt can command the respect of the berserkers who inhabit Strahd's domain. They will not attack the character or that character's companions unless provoked.
The issue with harvested poison not going bad, from a game balance perspective, is the having an unstated amount of times in a given day the attempt can be made. Once? Once/day? Unlimited?
Why not retire and sell poison on the black market?!
The issue with harvested poison not going bad, from a game balance perspective, is the having an unstated amount of times in a given day the attempt can be made. Once? Once/day? Unlimited?
Why not retire and sell poison on the black market?!
Im just curious.
the dm has several control options if poisons get out of hand.
very few poisons have actual prices so the dm gets to set them.
dm has control of number of attempts I have never seen more than once on a dead body.
dm controls creature access. captured or abused animals will attempt escape or just die. phb beasts are really the only good access.
The issue with harvested poison not going bad, from a game balance perspective, is the having an unstated amount of times in a given day the attempt can be made. Once? Once/day? Unlimited?
Why not retire and sell poison on the black market?!
See the bit about how the creature has to be dead or incapacitated? That's inherently weird, right? I am convinced the original RAI was that poison harvesting isn't milking at all, but rather involves cutting the poison glands/sacs/whatever out of the creature, and that never made it into the text.
How complex you want your homebrew to be on fixing the problem is up to you, but I agree with Rosco - it's better to limit the milking process itself than to slap expiration dates on (stored) poisons. Here's a suggestion to get started:
If the creature's poison ability has a per-time limit on it already, such as a flumph's 1/day poison, milking it consumes uses, and if it's out of uses, you can extract one more dose ever by killing the creature and ripping its glands out. X/day and X/long rest and X/dawn are equivalent terms here.
If the creature's poison ability has a "recharge", like a green dragon wyrmling's 5+ poison gas, re-interpret that as per-rest as follows: take the lowest number of the recharge (so 6 for 6 or 6+, 5 for 5-6 or 5+, etc), subtract it from 7. So 6+ is 1/rest, 5+ is 2/rest, and so on.
X/rest poison consumes uses, like X/long rest does, but creatures can't short rest more than twice per day to recover their poison, so they can't be milked out more than 3 times total. If the creature is a PC or PC ability - e.g. you're milking the party Druid or the party Beast Master's beast - and you want to allow for more short rests for the party to recover, you can limit this rule to milked poison. As with long rest poison, you can extract 1 dose by killing a creature, even if it's out of uses. That means if you're milking our Wyrmling over time, it can provide 6 gas doses per day.
Always-on poison is problematic because most monster poisons are always on, with no clear way to fairly judge how many doses a monster genuinely has. Sticking with our wyrmling - which we already decided has poison gas 2/short rest, remember - as an example, the creature has always-on 1d6 poison in its bite. How to decide? I think the fairest way is to treat it as recharge 1+, which is 6/rest, or 18/day nonlethally.
Poisons having expiration dates after being applied would nullify many traps, which is why I think the DMG poisons last indefinitely. It's also weird for poisons to expire while sealed up - potions certainly don't - and we have no rules for e.g. sealing up a pouch, case, or quiver to prevent evaporation and the like. There are other methods to limit how valuable it is to retire and sell poisons.
First of all, poison prices are ludicrous and should be cut down to size. 10 gp is enough for a "dose" of silver to silver an arrow, and 50 is enough to adamantine one, multiplying both by 10 to modify a weapon. Absolutely no one should be buying basic poison at 33.33 (or 100 - unlike every other poison in the game, this poison works like silver and adamantine, so dose count depends on object type) gp per dose; a DC 10 Con save with 1d4 poison damage on failure is so bad, its expected damage against a commoner is 1.125, or put differently, if you coat a blowgun needle in it and shoot the commoner while sporting a Dexterity modifier of -1 (so the needle does 0 damage; basic poison is a contact poison), its odds of killing the commoner are 0.1125.The poison is much less useful in real combat.
You can work out how much damage a poison does to a Commoner by taking its average - let's take Basic Poison, so 2.5. If the save nullifies all damage, as it does for Basic Poison, saved damage is 0. If a poison lets you save for half damage, its average save damage is average/2-1/4. For example, 2.5/2-0.25=1, which is how much damage it inflicts on average when halved. The Commoner fails saves with odds (DC-1)/20. So for an XdY poison, save DC Z for half, damage taken is:
The prices in the DMG don't make sense - both Purple Worm Poison and Serpent Venom deal more expected poison damage per gp than Wyvern Poison (or equivalently, cost less gp per damage). You would expect the formula to either be constant, or for more potent poison to be less efficient - not for the curve to change direction. I made a google sheet to try out the formula of squaring the damage, setting the gp cost equal to that, and then converting to "round" numbers by figuring out units by refusing to list prices in hundreds of units unless forced, and then ceiling to the next of that unit. It worked out pretty well!
The issue with harvested poison not going bad, from a game balance perspective, is the having an unstated amount of times in a given day the attempt can be made. Once? Once/day? Unlimited?
Why not retire and sell poison on the black market?!
See the bit about how the creature has to be dead or incapacitated? That's inherently weird, right? I am convinced the original RAI was that poison harvesting isn't milking at all, but rather involves cutting the poison glands/sacs/whatever out of the creature, and that never made it into the text.
How complex you want your homebrew to be on fixing the problem is up to you, but I agree with Rosco - it's better to limit the milking process itself than to slap expiration dates on (stored) poisons. Here's a suggestion to get started:
If the creature's poison ability has a per-time limit on it already, such as a flumph's 1/day poison, milking it consumes uses, and if it's out of uses, you can extract one more dose ever by killing the creature and ripping its glands out. X/day and X/long rest and X/dawn are equivalent terms here.
If the creature's poison ability has a "recharge", like a green dragon wyrmling's 5+ poison gas, re-interpret that as per-rest as follows: take the lowest number of the recharge (so 6 for 6 or 6+, 5 for 5-6 or 5+, etc), subtract it from 7. So 6+ is 1/rest, 5+ is 2/rest, and so on.
X/rest poison consumes uses, like X/long rest does, but creatures can't short rest more than twice per day to recover their poison, so they can't be milked out more than 3 times total. If the creature is a PC or PC ability - e.g. you're milking the party Druid or the party Beast Master's beast - and you want to allow for more short rests for the party to recover, you can limit this rule to milked poison. As with long rest poison, you can extract 1 dose by killing a creature, even if it's out of uses. That means if you're milking our Wyrmling over time, it can provide 6 gas doses per day.
Always-on poison is problematic because most monster poisons are always on, with no clear way to fairly judge how many doses a monster genuinely has. Sticking with our wyrmling - which we already decided has poison gas 2/short rest, remember - as an example, the creature has always-on 1d6 poison in its bite. How to decide? I think the fairest way is to treat it as recharge 1+, which is 6/rest, or 18/day nonlethally.
Poisons having expiration dates after being applied would nullify many traps, which is why I think the DMG poisons last indefinitely. It's also weird for poisons to expire while sealed up - potions certainly don't - and we have no rules for e.g. sealing up a pouch, case, or quiver to prevent evaporation and the like. There are other methods to limit how valuable it is to retire and sell poisons.
First of all, poison prices are ludicrous and should be cut down to size. 10 gp is enough for a "dose" of silver to silver an arrow, and 50 is enough to adamantine one, multiplying both by 10 to modify a weapon. Absolutely no one should be buying basic poison at 33.33 (or 100 - unlike every other poison in the game, this poison works like silver and adamantine, so dose count depends on object type) gp per dose; a DC 10 Con save with 1d4 poison damage on failure is so bad, its expected damage against a commoner is 1.125, or put differently, if you coat a blowgun needle in it and shoot the commoner while sporting a Dexterity modifier of -1 (so the needle does 0 damage; basic poison is a contact poison), its odds of killing the commoner are 0.1125.The poison is much less useful in real combat.
You can work out how much damage a poison does to a Commoner by taking its average - let's take Basic Poison, so 2.5. If the save nullifies all damage, as it does for Basic Poison, saved damage is 0. If a poison lets you save for half damage, its average save damage is average/2-1/4. For example, 2.5/2-0.25=1, which is how much damage it inflicts on average when halved. The Commoner fails saves with odds (DC-1)/20. So for an XdY poison, save DC Z for half, damage taken is:
The prices in the DMG don't make sense - both Purple Worm Poison and Serpent Venom deal more expected poison damage per gp than Wyvern Poison (or equivalently, cost less gp per damage). You would expect the formula to either be constant, or for more potent poison to be less efficient - not for the curve to change direction. I made a google sheet to try out the formula of squaring the damage, setting the gp cost equal to that, and then converting to "round" numbers by figuring out units by refusing to list prices in hundreds of units unless forced, and then ceiling to the next of that unit. It worked out pretty well!
Basic Poison: 100 gp for 3 doses -> 39 sp for 3 doses
Purple Worm: 2000 gp -> 160 pp (1600 gp)
Serpent: 200 gp -> 61 gp
Wyvern: 1200 gp -> 44 pp (440 gp)
The linked sheet ought to correctly multiply poison damage by 21/20 when there is no save, as the poison can crit, provided there are damage dice.
that just shows some things in can't be distilled to a balanced formula. math becomes so complex and includes too many x factors to distill down to simple formulas. in the realworld people make a living guessing market values but there will always be outliers and unique circumstances.
Things like expiration - legality - availability - detectability are all distanced from a simple formula and a dm just needs to decide. Many dms roll random market price alterations. some allow charisma style bartering to take place.
Also there is an old debate about breath weapons and being harvestable. dragonborn and dragons specifically. just dealing poison damage does not make a poisonous creature. just like drow poisonous weapons or sprites which is why they were deliberately removed from the thread in the rules. (Hence no link, interested people can look them up themselves)
the debate is Basically magic that does poison is not equal to being a poisonous creature.
Enchanted Hair. Korreds have hair all over their bodies, but the hair that grows from their heads is magical. When cut, it transforms into whatever material was used to cut it. Korreds use iron shears to cut lengths of their hair, then weave the strands together to create iron ropes that they can manipulate, animating them to bind or snake around creatures and objects. Korreds take great pride in their hair, and equally great offense at anyone who attempts to cut it without permission.
along the line of hair..... I will allow any spider creature to craft rope/ webing in their downtime. the game says they have the ability to create webs if they have websense. so i just follow general crafting rules.
I am torn because I'd love harvesting, crafting, foraging, and similar activities to be well worth pursuing, but I think that you get one chance to harvest from a given creatures. And that's it.
Crafting and Harvesting Poison
During downtime between adventures, a character can use the crafting rules in the Player’s Handbook to create basic poison if the character has proficiency with a poisoner’s kit. At your discretion, the character can craft other kinds of poison. Not all poison ingredients are available for purchase, and tracking down certain ingredients might form the basis of an entire adventure.
A character can instead attempt to harvest poison from a poisonous creature, such as a snake, wyvern, or carrion crawler. The creature must be incapacitated or dead, and the harvesting requires 1d6 minutes followed by a DC 20 Intelligence (Nature) check. (Proficiency with the poisoner’s kit applies to this check if the character doesn’t have proficiency in Nature.) On a successful check, the character harvests enough poison for a single dose. On a failed check, the character is unable to extract any poison. If the character fails the check by 5 or more, the character is subjected to the creature’s poison.
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The game has several listed crafting options and starters for created magic items. There are also some creatures with harvestable goods.
thread rules
Some examples are.
Tressym. they are great for both alternate familiars and beast companions. detect invisibility and poisons are both too good. also understands common not just commands.
flail snail is directly referenced in the creation of two powerful magic items. spellguard shield and robe of scintillating colors
Are we allowed to post rules from the game on these forums?
absolutely. as long as its a direct game use. I just don't want or need class comparisons.
I even want suggested rules. like ones that require "dms to make a call" for example we have solid poison harvesting rules but the number of times a creature can be harvested (if the creature is alive) is undefined/left up to the dm.
Purple worm has one of the most valuable and potent poisons in the game even one use is incredible.
flying snake poison is not an item but the game implies that it is and a unique one that bypasses saves.
Plants, animals, and minerals, oh my!
Question. How long does harvested poison last?
I love crafting and give players a one time chance to take gold as “experience” instead of money. A couple of things.
1. As a DM I use narrative leveling (milestone leveling), so experience points aren’t a thing as such.
2. As a DM I use variant encumbrance, so weight is a huge issue (50 coins = 1 pound).
3. I hate the idea of a outdoor character needing to have money to make something, like needing 25 gp worth of materials to make a potion of healing.
All of this means that a character can take their cut of some treasure, say 100 gp, and keep 25 gp, but take the remaining 75 as XP! This 75 XP can be spent on a 1 XP per 1 gp ratio, using it to feed the raw material costs to craft things that they would be able to given their tools, supplies, proficiencies, and time.
I assume poisons don't fail unless the dm tells you they do. I assume part of the harvesting process is preservation.
there are some spots where healing potions going bad and (turn into poison) are referenced. (curse of strahd modules and the main adventure book) but that is usually unbelievably old ones or ones in areas with magical entropy.
Along that same line, it cost 25 gold worth of materials. There is nothing to say those materials aren't harvested from creatures or found as plants in the wilderness. they are just 25 gp worth of materials. How much effort is 25gp for an adventurer? I think roughly 2-5 days of collecting for skilled labor in xanathars.
dms should absolutely allow people to harvest and collect raw ingredients to by pass cost.
The only poisons in the core game with rules for "going bad" are PHB basic poison and the poison made by the poisoner feat. The standard poison rules were errated into the DMG, so the knowledge is public - here's the link: https://media.wizards.com/2018/dnd/downloads/DMG-Errata.pdf
Contact and injury poisons should last until delivered or washed off, after being applied to an object, and neither has rules for going bad, so they don't. Ingested and inhaled poisons don't have any rules for lasting until delivered or washed off, but I'm sure DM discretion applies - for example, we all know wine turns to vinegar, but it's not like arsenic will go bad in the can.
Something you'll need your DM to rule on is whether poisons are contact or injury - all monster poisons are written to use the contact rules (i.e. if you're bitten by a flying snake and are a raging barbarian, so you reduce the piercing damage to 0, you still take the poison damage - which definitionally means it's contact poison, not injury poison). This includes the already-mentioned Purple Worm poison - when a Purple Worm attacks you, it's contact, but if you harvest it and use it, it's injury. Looks like dndbeyond hasn't got purple worm poison in its item list, or I'd link it.
Carrion Crawler mucus is an incredibly useful poison which also highlights the difficulties here: when the monster uses it, it causes poison damage, but the harvested poison only causes poisoned and paralyzed. And there's no visible distinction between the crawler's rules and worm's rules, in terms of working out that the crawler's poison is contact in a PC's hands, but the worm poison changes to injury.
With respect to PC abilities, one of the best damaging poisons is flying snake poison, which is more powerful than giant toad poison. Both share the very hard to get quality of being able to crit, since there's no save to resist the poison damage. Theoretically Crawler poison would have this too, except that as I said, the DMG says harvested Crawler poison stops doing damage.
Bats Have guano which is a valuable crafting component
sheep have fur which is a material component
birds have feathers which is a material component.
eyes of various creatures are also material components.
this implies they are part of the crafting process for Magic items that have similar effects or cast those spells.
stench kow is clearly an inhaled poison. Stench. Any creature other than a stench kow that starts its turn within 5 feet of the stench kow must succeed on a DC 12 Constitution saving throw or be poisoned until the start of the creature’s next turn. On a successful saving throw, the creature is immune to the stench of all stench kows for 1 hour.
dretch is in the same boat but has a listed use number. basically like the spell slow.
Fetid Cloud (1/Day). A 10-foot radius of disgusting green gas extends out from the dretch. The gas spreads around corners, and its area is lightly obscured. It lasts for 1 minute or until a strong wind disperses it. Any creature that starts its turn in that area must succeed on a DC 11 Constitution saving throw or be poisoned until the start of its next turn. While poisoned in this way, the target can take either an action or a bonus action on its turn, not both, and can't take reactions.
Ghast has a similar effect.
and I haven't even suggested diseases yet.
I went on a little adventure looking through low-intelligence monsters to possibly hunt for poison, and I came across this beauty: assassin vine. That's clearly a contact vector (the vine doesn't even hit you - you get poisoned by touching it too much for too long), no-save 6d6 (21) poison, and on a CR 3 creature, to boot. I'd rather invest in assassin vine poison than purple worm poison.
the problem is access.. no dm is going to make that regularly available in shops. still good catch I approve.
Curse of strahd has Sangzor a "demon possessed? goat" that has pelt rules built into the module.
A character who wears Sangzor's pelt can command the respect of the berserkers who inhabit Strahd's domain. They will not attack the character or that character's companions unless provoked.
The issue with harvested poison not going bad, from a game balance perspective, is the having an unstated amount of times in a given day the attempt can be made. Once? Once/day? Unlimited?
Why not retire and sell poison on the black market?!
Im just curious.
the dm has several control options if poisons get out of hand.
Let's get the RAW we have up in here (including the poison items I tried and failed to link earlier): https://www.dndbeyond.com/sources/dmg/running-the-game#Poisons
See the bit about how the creature has to be dead or incapacitated? That's inherently weird, right? I am convinced the original RAI was that poison harvesting isn't milking at all, but rather involves cutting the poison glands/sacs/whatever out of the creature, and that never made it into the text.
How complex you want your homebrew to be on fixing the problem is up to you, but I agree with Rosco - it's better to limit the milking process itself than to slap expiration dates on (stored) poisons. Here's a suggestion to get started:
Poisons having expiration dates after being applied would nullify many traps, which is why I think the DMG poisons last indefinitely. It's also weird for poisons to expire while sealed up - potions certainly don't - and we have no rules for e.g. sealing up a pouch, case, or quiver to prevent evaporation and the like. There are other methods to limit how valuable it is to retire and sell poisons.
First of all, poison prices are ludicrous and should be cut down to size. 10 gp is enough for a "dose" of silver to silver an arrow, and 50 is enough to adamantine one, multiplying both by 10 to modify a weapon. Absolutely no one should be buying basic poison at 33.33 (or 100 - unlike every other poison in the game, this poison works like silver and adamantine, so dose count depends on object type) gp per dose; a DC 10 Con save with 1d4 poison damage on failure is so bad, its expected damage against a commoner is 1.125, or put differently, if you coat a blowgun needle in it and shoot the commoner while sporting a Dexterity modifier of -1 (so the needle does 0 damage; basic poison is a contact poison), its odds of killing the commoner are 0.1125. The poison is much less useful in real combat.
You can work out how much damage a poison does to a Commoner by taking its average - let's take Basic Poison, so 2.5. If the save nullifies all damage, as it does for Basic Poison, saved damage is 0. If a poison lets you save for half damage, its average save damage is average/2-1/4. For example, 2.5/2-0.25=1, which is how much damage it inflicts on average when halved. The Commoner fails saves with odds (DC-1)/20. So for an XdY poison, save DC Z for half, damage taken is:
((21-Z)*(X*(Y+1)-1)/4 + (Z-1)*X*(Y+1)/2)/20 = (Z-21+X*(1+Y)*(19+Z))/80
The prices in the DMG don't make sense - both Purple Worm Poison and Serpent Venom deal more expected poison damage per gp than Wyvern Poison (or equivalently, cost less gp per damage). You would expect the formula to either be constant, or for more potent poison to be less efficient - not for the curve to change direction. I made a google sheet to try out the formula of squaring the damage, setting the gp cost equal to that, and then converting to "round" numbers by figuring out units by refusing to list prices in hundreds of units unless forced, and then ceiling to the next of that unit. It worked out pretty well!
Link is here: https://docs.google.com/spreadsheets/d/1r0eoDjhBBFCD4rRy3sc-DjlTaJnRvX0M3o1gv9Fnffc/edit?usp=sharing (Make your own copy to input some poison values).
Prices:
Basic Poison: 100 gp for 3 doses -> 39 sp for 3 doses
Purple Worm: 2000 gp -> 160 pp (1600 gp)
Serpent: 200 gp -> 61 gp
Wyvern: 1200 gp -> 44 pp (440 gp)
The linked sheet ought to correctly multiply poison damage by 21/20 when there is no save, as the poison can crit, provided there are damage dice.
that just shows some things in can't be distilled to a balanced formula. math becomes so complex and includes too many x factors to distill down to simple formulas. in the realworld people make a living guessing market values but there will always be outliers and unique circumstances.
Things like expiration - legality - availability - detectability are all distanced from a simple formula and a dm just needs to decide. Many dms roll random market price alterations. some allow charisma style bartering to take place.
Also there is an old debate about breath weapons and being harvestable. dragonborn and dragons specifically. just dealing poison damage does not make a poisonous creature. just like drow poisonous weapons or sprites which is why they were deliberately removed from the thread in the rules. (Hence no link, interested people can look them up themselves)
the debate is Basically magic that does poison is not equal to being a poisonous creature.
Korred has a unique feature.
Enchanted Hair. Korreds have hair all over their bodies, but the hair that grows from their heads is magical. When cut, it transforms into whatever material was used to cut it. Korreds use iron shears to cut lengths of their hair, then weave the strands together to create iron ropes that they can manipulate, animating them to bind or snake around creatures and objects. Korreds take great pride in their hair, and equally great offense at anyone who attempts to cut it without permission.
along the line of hair..... I will allow any spider creature to craft rope/ webing in their downtime. the game says they have the ability to create webs if they have websense. so i just follow general crafting rules.
Also imagine a character who uses no metal armor riding a rust monster into battle. feeding it should be no problem.
or collecting acid from a gray ooze (note acid is not given the same rules as poison.)
I am torn because I'd love harvesting, crafting, foraging, and similar activities to be well worth pursuing, but I think that you get one chance to harvest from a given creatures. And that's it.