Critical combat maneuver?

Question

When you attempt to perform a combat maneuver, make an attack roll and add your CMB in place of your normal attack bonus.

Combat maneuvers are apparently attacks, and rolls made to attempt a combat maneuver are attack rolls. As such, they should be capable of producing a critical threat, which would then need to be confirmed, since the critical rules are a property of attack rolls.

This doesn’t appear to generally do anything, since combat maneuvers deal no damage, so there’s nothing to multiply, but it seems like it would “count” as a critical hit, so if you had something that says “whenever you score a critical hit...” (and there are several of those), it should trigger. Plus, one of the things you can do with a successful combat maneuver roll while grappling is to deal damage: if that roll was a critical, that damage might be eligible for multiplying.

But nowhere else in the rules seems to reference this. Natural 20s on the combat maneuver roll are explicitly mentioned, but no connection is drawn to the critical rules of attacks.

The questions I’m looking for answers to are as follows:

• Is there anything I’ve missed, that disbars combat maneuvers from threatening criticals in the first place?

• If your success on a combat maneuver roll results in damage (e.g. one of the options while grappling), is this damage eligible for multiplication if the combat maneuver roll was a confirmed critical hit?

• How do you handle the critical threat range of the weapon they were using? Could a disarm with a rapier threaten a critical on a roll of 18? What about grappling while you had a kukri?

• What is the target for the confirmation roll: their AC, or their CMD? (Unless someone shows differently, you would definitely continue to use CMB since the confirmation rules say you use the same bonus as on the original attack.)

Are there any official statements made about any of this? I have found a few forum discussions (Paizo’s forum, Giant in the Playground forum), but none seemed to result in developer involvement, or even in detailed consideration of the issue.

If no official statements are available, I would be interested in listening to descriptions of how you have handled this, or seen this handled, in one of your actual games that you have actually played. That is, I am not interested in speculation and I am not interested in how you think you’d rule it now that you think about it. But if this actually came up in a game, I’d be interested in how you answered these questions, particularly if combat-maneuver criticals were allowed to happen.

Answer 1

Combat maneuvers can't score threats

In the discussion of the Paizo Blog post Combat Maneuvers and Weapon Special Features Pathfinder designer Sean K. Reynolds in Oct. 2011 posted this question-and-answer:

If you have Tripping Strike and attempt to disarm someone, can you "crit" the disarm attempt and thereby trigger your Tripping Strike?

Combat maneuvers don't have threat ranges and can't critically hit.

To my knowledge, this hasn't been contradicted and remains Pathfinder's official stance.

Answer 2

Rules

Yes, a combat maneuver can be a critical threat. The critical threat rules are part of an attack roll, and a combat maneuver specifically makes an attack roll.

Attack Roll
An attack roll represents your attempt to strike your opponent on your turn in a round. When you make an attack roll, you roll a d20 and add your attack bonus. (Other modifiers may also apply to this roll.) If your result equals or beats the target's Armor Class, you hit and deal damage.
Automatic Misses and Hits: A natural 1 (the d20 comes up 1) on an attack roll is always a miss. A natural 20 (the d20 comes up 20) is always a hit. A natural 20 is also a threat—a possible critical hit (see the attack action).

The attack action rules for critical hits apply to all attack rolls, not just the attack action.

Critical Hits: When you make an attack roll and get a natural 20 (the d20 shows 20), you hit regardless of your target's Armor Class, and you have scored a “threat,” meaning the hit might be a critical hit (or “crit”). To find out if it's a critical hit, you immediately make an attempt to “confirm” the critical hit—another attack roll with all the same modifiers as the attack roll you just made. If the confirmation roll also results in a hit against the target's AC, your original hit is a critical hit. (The critical roll just needs to hit to give you a crit, it doesn't need to come up 20 again.) If the confirmation roll is a miss, then your hit is just a regular hit.
...

You use your opponent's CMD in place of their AC for attack rolls made as part of a combat maneuver. (A different GM could rule you use AC for the confirmation roll, but that would only be more advantageous for the character attempting the combat maneuver).

If your success on a combat maneuver roll results in damage, that damage is multiplied if the combat maneuver roll was a confirmed critical hit.^†

A critical hit means that you roll your damage more than once, with all your usual bonuses, and add the rolls together. ...

In order to use the threat range from a weapon for your critical threat range on a combat maneuver you must be using that weapon to perform the maneuver. There are no rules in general about what weapons you can use to perform maneuvers. You must use an "unarmed strike, a natural attack, or an attack made with armor spikes or a light or one-handed weapon" to deal damage during a grapple.

Experience

In practical game play experience, the abilities to expand threat range and start triggering effects on criticals come at about the same levels that combat maneuvers begin to lose their effectiveness. Since it's hard to get multiple combat maneuvers per turn, they aren't as impressive a way to stay in the game than full attacking with a huge reach and dazing assault. Remember that the expanded threat range and effects that trigger "must be applicable to the weapon or attack used to perform the maneuver".

To adjudicate a critical hit on a combat maneuver I do the following.

1. Make the attack roll for the combat maneuver.

2. If the natural result of the attack roll is in the threat range of the weapon used to make the combat maneuver it is a threat.

3. Roll again to confirm the threat (CMB vs CMD). The roll uses all of the same bonuses as before, and results in a critical hit under exactly the same circumstances that would result in the previous roll being a successful maneuver.

4. Add the effect of the critical hit rule itself. If the combat maneuver does damage (sunder^† or damage an opponent during a grapple) you will roll the weapon damage a second time (or more) and add it to the damage. If the maneuver doesn't deal damage, the critical hit doesn't result in dealing damage. This is because you roll the damage more than once. If you aren't rolling damage there's no damage to roll again.

   A critical hit means that you roll your damage more than once, with all your usual bonuses, and add the rolls together

5. Add any extra effects that trigger on confirming the critical hit (extra damage, will provoke an attack of opportunity from allies, etc). Provoked attacks of opportunity (such as those from seize the moment) are resolved immediately, before the combat maneuver itself is resolved. Add extra damage that triggers on a critical (such as from a flaming burst weapon), even if the combat maneuver itself doesn't deal damage.

6. Resolve the effects of the combat maneuver. If the maneuver deals damage (or is going to deal extra damage), this is when it is dealt.

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^†It's difficult to actually get a critical hit while sundering because objects are immune to critical hits.