Creating Poisons

The vast majority of applications of poisons (at least, those characters can get their hands on) will be crafted in some capacity. Characters can choose whether they quickly craft the poison or use downtime to do so; each has benefits and drawbacks, which are described below.

Quick Poison Crafting

Quickly crafting a poison requires eight hours of processing, only one hour of which must be spent actively working and may coincide with a long rest (this does prevent the character from doing any other activity if they also wish to benefit from a long rest). This yields a single dose of poison, but a character can spend an extra hour of active work to gain a second identical dose if they so desire.
The character may use more than one ingredient per dose; if multiple doses of poison are being made, they must use the same ingredients in both. When two ingredients are used, the character has advantage on the checks to craft the poison; if three or more ingredients are used, the character gains an additional +1 bonus to the checks per extra ingredient.
When a character quickly crafts a poison, they should make the following checks:

• Intelligence (Poisoner’s Kit) to set the process up and prepare the equipment for processing.

• Intelligence (Nature) to effectively prepare the components to be turned into a poison.

• Wisdom (Poisoner’s Kit) to ensure the poison is developing in the desired way.

The crafted poison has a potency equal to the lower of the two intelligence checks, with a maximum of 15. If the result of the last check was at least 15, the poison takes on an additional effect beyond simply damaging the target. This additional effect is selected randomly from the secondary effects of all the components used. Finally, the route of administration of the poison (see Optional Variant Rule: Administering Poisons below) is always injected when the poison is quickly crafted.

Downtime Posion Crafting

Using downtime to craft a poison can produce much more potent poisons with much greater control over the effects and how they can be administered. Of course, using downtime does involve a significant time investment which a character either may not want to invest… or might not be able to.

• Resources. Using downtime to craft poisons requires at least one workweek of dedicated effort. Additionally, one must have poisonous components that can be developed over the week into a viable poison. Part of the process involves using reagents that aren’t typically found in nature and must be purchased. These reagents cost 100 gp and can be found being sold by most general goods merchants, though they are probably typically referred to by other names, such as “varmint control supplies.” The character can purchase additional or higher quality reagents; for each additional 500 gp spent, the potency of the final poison gains a +1 bonus.

• Resolution. Crafting a poison requires using both a poisoner’s kit and alchemist’s supplies. To begin the process, the crafter must be proficient with at least one of these tools. Once the character has the tools required, they must decide how much gold they wish to invest into the process, which will not affect the checks they must make but will affect the finished product. This investment must be made before any checks are rolled and cannot be recovered if the process does not produce a particularly high-quality poison.

Using downtime to create a poison always results in some degree of success. However, creating a low potency toxin with poor rolls is still possible, which may be considered a failed crafting, particularly if the result is extremely low. The actual process involves making three checks. The first two are Intelligence (Poisoner’s Kit) and Intelligence (Alchemist’s Supplies) to ensure that all the equipment is being used properly. The final check is an appropriate check of the character’s choice.
Typically, only one week of work is required to make poison of any rarity because the components used to make an extremely rare poison generally are already potent. However, at the game master’s discretion, some poisons may require multiple weeks to create – which will involve gathering extra materials and investing additional gold.

Crafting Results

Crafting a poison is unique in that it doesn’t involve successes and failures the same way that other crafting does. Instead, the poison created may be of exceptionally low potency, rendering it virtually useless, though it was still technically created. The route of administration for the poison is the one described by the components used; if the poison was crafted with components that have multiple routes of administration, the route the poison uses is selected randomly.
Likewise, the secondary effect from the poisonous components used is always applied; if multiple components were used with different secondary effects, select randomly which one was applied. When the character makes their checks as part of the downtime, compare the results of the roll to the potency range possible for the poison to determine its final potency.

• All Three Rolls Exceed the Maximum of the Potency Range

  In this case, the poison takes on the maximum possible potency for the rarity of the components. If extra reagents were purchased at the beginning of the process, they are not consumed and may either be resold for one-half their original value or saved for future crafting.

• At Least One Roll Is at Least the Minimum of the Potency Range

  In this case, the potency begins at the minimum end of the range. For each additional roll that was at least the minimum, the potency gains a +1 bonus to the potency. If at least one of the rolls was greater than the maximum, the potency gains an additional +2. Finally, any bonus for purchasing reagents is applied. The potency can never exceed the maximum potency possible for the rarity of the components used; if an excess of reagents was purchased, they are lost and cannot be refunded.

• No Rolls are Greater than the Minimum of the Potency Range

  In this case, the poison has the lowest possible potency for the components used and no bonus from purchasing additional or higher quality reagents can be obtained.

Sample Tables

Sample Poisonous Plants

Sample Poisonous/Venomous Creatures

Source: DM Lair - Poisons Explored

Useful Links

• Flora Folder

Determining Damage and DC's of a Crafter Poison