Do critical hit effects fail on critical hit negation?

[Senko]

I did google this but most of what I found was in relation to starfinder or 2nd edition. If a creature is immune to critical hits and precision damage are they also immune to the rider effects of that critical hit?

For example if a player had dispelling critical and scored what would normally be a critical hit on an undead would they be able to forgo the damage to cast a dispel on it or would the negation of the critical negate the abilities that trigger on a critical hit?

Dispelling Critical (Critical)
Source Ultimate Combat pg. 97
Your blows attack the physical and arcane forms of your enemies at the same time.

Prerequisites: Arcane Strike, base attack bonus +11, ability to cast dispel magic.

Benefit: If you have dispel magic prepared or can cast it spontaneously, when you score a critical hit against an opponent, you may use a swift action to cast dispel magic to make a targeted dispel against that opponent.

[Chell Raighn]

It largely depends on the wording of the ability that provides the critical immunity… some sources specifically only negate the bonus damage. Rider effects would still apply on those… most however do negate everything.

[Senko]

Wording is very basic . . .

Indestructible: At 20th level, the incanter becomes immune to critical hits and precision damage. When below 0 hit points, he does not die until his negative total is in excess of twice his Constitution score.

[Chell Raighn]

Negates the entire critical hit, rider effects and everything…

There are also some rider effects that don’t care about crit immunity though… but dispelling critical is not one of them… such effects use wording like “when you would score a critical” implying that you only need to qualify for a critical to apply the effect, immunity to critical hits don’t necessarily negate the qualifying conditions to score a critical hit.

[Phoebus Alexandros]

Undead Type wrote:

Immunity to all mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms).

Immunity to bleed, death effects, disease, paralysis, poison, sleep effects, and stunning.
Not subject to nonlethal damage, ability drain, or energy drain. Immune to damage to its physical ability scores (Constitution, Dexterity, and Strength), as well as to exhaustion and fatigue effects.
...
Immunity to any effect that requires a Fortitude save (unless the effect also works on objects or is harmless).

To begin with, Undead are a poor example as they are not immune to critical hits by default.

Critical Feats wrote:

Critical feats modify the effects of a critical hit by inflicting an additional condition on the victim of the critical hit.

If something is immune to a critical hit, and has not had an effect inflicted on it, what is there for a critical feat to modify?

[Mudfoot]

As a related question, does a swashbuckler regain panache if her critical hit is negated by Fortification armour? I'd assume not.

[Chell Raighn]

Mudfoot wrote:

As a related question, does a swashbuckler regain panache if her critical hit is negated by Fortification armour? I'd assume not.

Fortification triggers from a crit being scored in the first place, and only says to roll the damage as normal… this question came up in the group I play with once before, and one of our DMs found something stating that fortification just nullifies the critical hit damage, not the fact that a critical hit was scored… so yes a swashbuckler would regain panache… if there is a solid rule to the contrary I’d love to see it, but for now this is what we’ve been rolling with.

[Azothath]

on recovering Panache see Swashbuckler class scroll down for

Critical Hit with a Light or One-Handed Piercing Melee Weapon:

Critical Hit with a Light or One-Handed Piercing Melee Weapon: Each time the swashbuckler confirms a critical hit with a light or one-handed piercing melee weapon, she regains 1 panache point. Confirming a critical hit on a helpless or unaware creature or a creature that has fewer Hit Dice than half the swashbuckler’s character level doesn’t restore panache.

Killing Blow with a Light or One-Handed Piercing Melee Weapon: When the swashbuckler reduces a creature to 0 or fewer hit points with a light or one-handed piercing melee weapon attack while in combat, she regains 1 panache point. Destroying an unattended object, reducing a helpless or unaware creature to 0 or fewer hit points, or reducing a creature that has fewer Hit Dice than half the swashbuckler’s character level to 0 or fewer hit points doesn’t restore any panache.
===end===

so the basic ability description supports that the swashbuckler needs only confirm the critical not actually do damage or inflict a condition, unaware and helpless crtrs are an exception. As it seems to be about attitude & heroics I think it leaves GMs some leeway.
With 'killing blow' the swashbuckler must reduce the creature to 0HP or less.

there are subtle differences between the monster ability and magic ability.
Monster Fortification lets the creature treat the critical/precision as a normal hit. So here Panache is clearly recovered. ("as if" is not "as").
Fortification lets the hit creature negate the critical/precision. Again the critical was confirmed before it could be negated thus the panache is recovered.

again, as it is about attitude and heroics I would not be overly surprised if a story/dramatic centric GM denied panache recovery as the heroic action essentially fails when the critical is negated. (aka the bag of rats won't give you any panache).

[Mudfoot]

Sounds reasonable to me. I'll go with that, in the unlikely event that it ever comes up.