[RPG] How does “stacking” poisons affect the poison save DC

One successful crafting session = 1 dose of the poison in question.

From the Section on Crafting:

The basic function of the Craft skill, however, is to allow you to make an item of the appropriate type. The DC depends on the complexity of the item to be created. The DC, your check result, and the price of the item determine how long it takes to make a particular item. The item's finished price also determines the cost of raw materials.

That means 1 dose of poison (also see the feat below). This is slow. How can we make it faster?

Master Alchemist Feat

When making poisons, you can create a number of doses equal to your Intelligence modifier (minimum 1) at one time. These additional doses do not increase the time required, but they do increase the raw material cost. In addition, whenever you make alchemical items or poisons using Craft (alchemy), use the item's gp value as its sp value when determining your progress (do not multiply the item's gp cost by 10 to determine its sp cost).

Now we're cracking. So with the Master Alchemist feat, and an int bonus of +5, In a single week (assuming a Craft(Alchemy) of +20 and taking a 10) I can make 30 x 11 = 330 / 120 = 2.75 x 5 = 13.75 (round down) = 13 doses of Black Adder venom. Rock!

So, this is how poisons (and most other afflictions) work:

• You suffer the effects every time you fail a save
• The frequency tells you how often you make a save, once the onset time has passed
• If there is no onset, you make a save immediately
• The poison is finished when the conditions for a cure are met, or the duration has elapsed

For black adder venom, there is no onset, and the frequency is “1/round for 6 rounds”. The cure is “1 save”. That means that:

• Since there is no onset, when you are hit by the poison, you make a save immediately.
• If you fail, you take 1d2 Con damage. If you succeed, you've met the conditions for a cure, and so the poison is now out of your system.
• Because the frequency is “1/round for 6 round” you repeat this once per round until you either make a save (and thus are cured) or 6 rounds have elapsed. Every time you fail a save, you take the damage. This damage can be healed by any of the normal means of recovering strength (restoration spells, resting, etc.)

The second example of a sting is almost identical: the frequency and cure are the same, but the effect is being sickened. The effect is that you're sickened until the poison is up, which is either the first time you make a save or after 6 rounds. (Note that if someone e.g. used magic to heal you of the sickened effect, it would return the next round. It's 1 round of sickened applied 6 times in a row, not 6 rounds of sickened applied once.)

This all follows from the general rules for afflictions -- a category which include poisons and diseases. Diseases tend to have a longer onset time and lower frequency than poisons, but the basic mechanics are the same. If you still find yourself confused, take the time to read through the afflictions page I linked to.