How long does a poisoned weapon stay that way?

Question

This is a Pathfinder 2 question.

The rules for poisoning weapons seem contradictory, or at least redundant. Two different sections deal with this; I'm going to cite them both because I'm thinking about running a Rogue/Alchemist and so they are both relevant.

PH pg. 550, the relevant bit under "Method of Exposure" reads (as amended):

Injury: An injury poison is activated by applying it to a weapon or ammunition, and it affects the target of the first Strike made using the poisoned item. If that Strike is a success and deals piercing or slashing damage, the target must attempt a saving throw against the poison. On a failed Strike, the target is unaffected, but the poison remains on the weapon and you can try again. On a critical failure, or if the Strike fails to deal slashing or piercing damage for some other reason, the poison is spent but the target is unaffected.

Note that it first says that being poisoned affects "the first Strike made", but then goes on to tell us the consequences of missing and critically failing with that Strike. If being poisoned only affects the first Strike you make, the rest of the text is unnecessary.

Similar on PH pg. 185, in the description of the Rogue's Poison Weapon feat (again as amended by errata):

You apply a poison to the required weapon; if you're not holding a poison and have a free hand, you can Interact to draw a poison as part of this action. If your next attack with that weapon before the end of your next turn hits and deals damage, it applies the effects of the poison, provided that poison can be delivered by contact or injury. If you critically fail the attack roll, the poison is wasted as normal.

Again, it tells us that the poison only has an effect if the "next attack with that weapon [...] hits and deals damage" -- and then goes on to remind us what happens on a critical failure even though that can never be relevant with the rules written as they are.

So that gives us two possible interpretations: Either a weapon stays poisoned until you critically fail your attack or hit without dealing damage, or it stays poisoned until you next attack with it and then stops being poisoned no matter what the outcome was. As the person playing the Rogue/Alchemist, I of course want the former to be correct -- it's likely to make a very big difference! The rules as written suggest that they went back and forth on this and then emitted a confusing set of rules.

Which way should this be played and why?

Answer 1

a weapon stays poisoned until you critically fail your attack or hit without dealing damage

I'm not seeing the confusion, to be honest. Although mildly contradictory on the surface, you've quoted the relevant rules. By default, an injury poison lasts until the first Strike is made with it. The Fail condition amends the default by saying the poison will remain rather than be expended, although a Critical Fail goes back to the default of expending the poison without effect. Lastly, if you use the weapon to somehow deal damage other than piercing or slashing (either because the weapon only deals Blunt, or through some other effect or special ability), the poison is also expended with no effect on a Hit or Critical Hit. If you somehow had a weapon that could apply different damage types in each strike, and you missed while it was in 'blunt' mode, you could potentially still apply the poison if it hit in slash or pierce mode.

Answer 2

I agree the rules are confusing. This is what I think makes the most sense:

1. A successful strike removes the poison from the weapon.
2. A critically failed strike removes the poison from the weapon.
3. Otherwise the poison lasts until it expires (if applicable to that poison).

If the poison was applied with the Poison Weapon feat, the following additional rule applies:

4. The poison is removed from the weapon at the end of the turn after it was applied.

If the poison was applied with the Poison Weapon feat, and you have the Improved Poison Weapon feat also:

5. Ignore rule 2 above.

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I agree that the rules are weird. It would be nice if all of the poisoned weapon rules were in the same place. Here is my rationale.

1. I think this is just the rules being unclear. The rules about critical fails and trying again on failure just make no sense unless the regular use is only meant to refer to successful strikes.
2. I think this is clear.
3. The rules say nothing about expiry other than in the Poison Weapon feats so I think the default is to assume that it doesn't expire until the poison does. Note that, at the DMs discretion, actions like swimming may remove the poison from the weapon.
4. This is clear.
5. Also quite clear.

Answer 3

The Poison Weapon feat grants additional benefits

The feat has different, more restrictive, rules because it also grants significant benefits.

A rogue does not have to use the Poison Weapon feat in order to apply poison to a weapon. The feat lets a character do so in a more action-efficient way. They spend one action to both retrieve and then also apply the poison. This would generally otherwise take longer.

If the character uses this more economical mode of applying poison to a weapon, then the restriction on the feat applies. This seems intended for balance: offset the improved action economy by limiting the action.

Poison applied without the benefit of the feat lasts indefinitely. Poison applied quickly is also applied sloppily, becoming useless after one round. If it were otherwise, the improved action economy would make rogues much more effective poisoners.