A few animals and vermins available as familiars have a poisonous attack. My personal familiar is a house centipede with a dazing poison. As a familiar, it has currently 5 effective hit dice and will get more when my character levels up. According to the Universal Monster Rules about the Poison special attack :

The saving throw to resist a poison is usually a Fort save (DC 10 + 1/2 the poisoning creature’s racial HD + the creature’s Con modifier; the exact DC is given in the creature’s descriptive text).

With 10 Constitution and 1 racial HD for the base creature, the DC is 10 as written on the Bestiary entry.

Is the DC on the Bestiary only here as an indication and changes if the creature gets more HD or Constitution, or is it an invariable number ?

PS : Can the poison be extracted from my familiar (preferably in a nonlethal way) to be used on weapons ?


2 Answers 2


The Rules Are... Ambiguous

The Universal Monster Rules regarding poison say that

... The saving throw to resist a poison is usually a Fort save (DC 10 + 1/2 poisoning creature's racial HD + creature's Con modifier; the exact DC is given in the creature's descriptive text).

The only ambiguous part of that rule regarding the centipede as a normal creature is the 'usually a Fort save' segment; the rest specifies how a poison's save DC is calculated, and that it will be calculated in the creature's descriptive text. Recalculating on a change of racial HD or of Con is the correct reading of the rule.

The rules are silent, however, as to whether the effective HD for effects are racial or not. One argument in favor is that the familiar has only one type of HD, and so they would be 'effective racial HD.' The argument against it is that the rules don't say that they are.

Both rulings have merit; the permissive ruling helps the familiar remain relevant as the master's level increases, and the restrictive ruling helps keep 'the rules don't say I can't' from being a useful argument.

Further Analysis

The clauses from the familiars section regarding HD is dichotomous:

... It retains the appearance, Hit Dice...


Hit Dice: For the purpose of effects related to number of Hit Dice, use the master's character level or the familiar's normal HD total, whichever is higher.

The second clause would override the first, depending on the definition of 'effects'. Since there is none in the glossary, extrapolation is necessary.

Within the glossary alone, there are hundreds of instances of the word 'effect' or 'effects'. Looking at the Afflictions Section, afflictions, including poisons, appear to have effects.

Thus the effects of poison that are related to HD should be calculated from the master's HD, when higher.

It's still ambiguous though. If they'd just define what an 'effect' is, then these questions would be a cakewalk.


This question actually touches on something that is highly debated across various forums and a Paizo Contributor has indicated that Paizo will likely errata it... at some point. (Source) (Quote- 4th post)

Increases to HD/CON (or whichever ability is relevant) DO increase DC, so you can use Bear's Endurance (etc) to increase it.

However, RAI, is that Familiar abilities' DC does NOT scale with the PC's HD, it uses the STATIC HD of the creature

  • (Ex) abilities aren't described as effects
    • however, spells have 'effects' that are based on HD
  • there doesn't seem to be any other point to indicate that the HD remains as the base creature.

Here's a longer explanation:

Currently, it is unclear which of the two conflicting HD rules for Familiers offensive abilities fall under:

It retains the appearance, Hit Dice, base attack bonus, base save bonuses, skills, and feats of the normal animal it once was, but is now a magical beast for the purpose of effects that depend on its type.

This seems to indicate that it's abilities are static based on the original creature. If you think about it, why else would they specify that it's HD remains the same?

For the purpose of effects related to number of Hit Dice, use the master's character level or the familiar's normal HD total, whichever is higher.

That would say it scales; but it's been pointed out various times that this seems to be targeted as a defensive mechanism to prevent a level 20 Wizard's familiar from being Sleep or instantly killed by other high level magic with HD rules.

ps: Sorry for the repost of the same conclusion, but I came to it from a different path so I thought it might be more accurate in that fashion.

pps: You can 'extract' your familiar's poison using Craft (Alchemy) or a skill such as a profession you and your GM agree would cover the necessary... skill... but the result would be at the same DC unless your GM wants to homerule it. You would essentially be 'making' poison from a handy source, but you would be receiving the same item you could otherwise make RAW.


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