Jason: Can you have a negative CMB? (specifically a target DC less than 15)


Combat & Magic


Jason, (though I don't mind additional discussion)

Simply put, can you have a negative CMB?

I realize in the 1.1 Designer Notes that a Natural 20 always hits, but with that in mind-

Is it possible to have a negative CMB? So that the base DC is less than 15?

My apologies if this has already been covered elsewhere.


Watcher wrote:

Jason, (though I don't mind additional discussion)

Simply put, can you have a negative CMB?

I realize in the 1.1 Designer Notes that a Natural 20 always hits, but with that in mind-

Is it possible to have a negative CMB? So that the base DC is less than 15?

My apologies if this has already been covered elsewhere.

I can't see why not - if you were say a 1st-level halfling wizard with 8 str, you'd have BAB 0 - 1 Str - 1 Size = -2. Your defensive CMB DC would be 15 - 2 = 13.

Does that answer your question?


Majuba wrote:


I can't see why not - if you were say a 1st-level halfling wizard with 8 str, you'd have BAB 0 - 1 Str - 1 Size = -2. Your defensive CMB DC would be 15 - 2 = 13.

Does that answer your question?

Not really. :D

I do appreciate the effort though. While I'm not always good with the game math, even I saw how it would be possible... As your example aptly demonstrated.

I suppose the question is more in keeping with 'would you ever have the base DC for any Combat Manuever be anything lower than 15?'

15 has always been a very standard benchmark to achieve. I just wondered if Jason ever thought it should be easier than that, in order to do the combat manuevers.

A strong human 1st level fight could have a CMB of 3, maing it a 50% chance of meeting the required target number against your halfling wizard. A really strong one could have an even better chance. Not bad for a combat manuever.

I'm not saying it's wrong or bad necessarily, it's just a straight forward question.


I feel I should point out the CMB penalty for Small size is -1, not -2. So, while it seems easy to perform maneuvers on said halfling wizard, it's probably not as easy as it was with the previous system, where said halfling wizard might have a -5 grapple modifier and then have to make an opposed check against the fighter, whose modifier is 8 higher.

In regards to the OP's question, every time I've seen only positive modifiers counted (while negative ones are ignored), the rules text explicitly says so. So, by inference, it's probably likely that negative modifiers do come into play in CMB determination.

Liberty's Edge

Watcher wrote:
I suppose the question is more in keeping with 'would you ever have the base DC for any Combat Manuever be anything lower than 15?'

I don't see why not, either.

Watcher wrote:

15 has always been a very standard benchmark to achieve. I just wondered if Jason ever thought it should be easier than that, in order to do the combat manuevers.

A strong human 1st level fight could have a CMB of 3, making it a 50% chance of meeting the required target number against your halfling wizard. A really strong one could have an even better chance. Not bad for a combat manuever.

No, but fitting, I think. Otherwise, the penalties that weaker characters would have little impact until higher levels.

Paizo Employee Director of Game Design

You can indeed have a negative CMB.

Jason Bulmahn
Lead Designer
Paizo Publishing


Jason Bulmahn wrote:

You can indeed have a negative CMB.

Jason Bulmahn
Lead Designer
Paizo Publishing

Wow! I woke up at 3 am to get a drink, and coincidentally Jason replies at the same time! Great timing!

Thanks for the answer!


This actually came up in my Burnt Offerings session last night. I'll try to avoid spoilers...

In the catacombs, there is a tiny sized creature with a low strength (-1). Despite it's reasonable BAB, the partys best tactic was to grapple the creature and once the party's barbarian did so the creature was easily defeated.

One thing that became apparent was that under the 3.5 rules the creature would have been a lot harder to grapple, because it's high touch AC would (most likely) have prevented it from being grappled in the first place. With the CMB change to grapple, it (and other creatures like it) are now a *lot* more vulnerable.

Now I can see the obvious solution is to just give the creature the Agile Maneuvers feat, but if every small dextrous creature has that feat then why not just make the CMB = your BAB + the better or your dex or str modifier in the first place?


Thats actually something I was considering, especially since the paradigm is already set by the trip manuver. A person plays to their strengths, and I have seen both brutally strong grapplers and disturbingly flexible/fast/nimble grapplers. I can see resisting a disarm being reflexively getting your weapon out of the way before the figurative "point of no return", or just gripping it tight enough that they don't get enough leverage to break your hold.

It works in my mind, and it would mean instead of learning a rule AND and exception or two(such as trip, or the feats) we just learn a rule.

Liberty's Edge

Pathfinder Companion, Pawns Subscriber; Pathfinder Roleplaying Game Superscriber; Starfinder Charter Superscriber
gr1bble wrote:

This actually came up in my Burnt Offerings session last night. I'll try to avoid spoilers...

In the catacombs, there is a tiny sized creature with a low strength (-1). Despite it's reasonable BAB, the partys best tactic was to grapple the creature and once the party's barbarian did so the creature was easily defeated.

One thing that became apparent was that under the 3.5 rules the creature would have been a lot harder to grapple, because it's high touch AC would (most likely) have prevented it from being grappled in the first place. With the CMB change to grapple, it (and other creatures like it) are now a *lot* more vulnerable.

Now I can see the obvious solution is to just give the creature the Agile Maneuvers feat, but if every small dextrous creature has that feat then why not just make the CMB = your BAB + the better or your dex or str modifier in the first place?

You make some good points, and unfortunately the creature in question doesn't have an extra feat slot (via the conversion) to take Agile Maneuvers with, but it is my experience that the difficulty with that particular encounter is not the touch AC but the necessity of having Improved Grapple to avoid an AoO that automatically cancels the grapple attempt if successful. With the removal of the auto-fail aspect of the AoO, grappling is much easier in general.

There is something to be said, too, for just using the higher of Dex or Str, but much the same logic applies to Weapon Finesse, both for creatures and PCs. A number of monsters get Weapon Finesse as a bonus feat, and pretty much any high-Dex-low-Str warrior type is going to have it, but the game still makes you burn a feat on it. I don't think Agile Maneuvers should be handled differently. Let the same creatures that get Weapon Finesse (or similar effects, like familiars get) for free also receive Agile Maneuvers, and otherwise, leave things alone.


Shisumo wrote:
it is my experience that the difficulty with that particular encounter is not the touch AC but the necessity of having Improved Grapple to avoid an AoO that automatically cancels the grapple attempt if successful.

Good point - I hadn't considered that, but it would have made a big difference in this case as well.

Shisumo wrote:
Let the same creatures that get Weapon Finesse (or similar effects, like familiars get) for free also receive Agile Maneuvers, and otherwise, leave things alone.

That makes sense (and is, in fact, what I've already done for the party's swashbuckler) and would definitely help things for the case in point. As you say, most tiny and smaller sized monsters with a low strength have Weapon Finesse anyway.

Taking it one step further - perhaps there shouldn't be an Agile Maneuvers feat at all and adding your Dex instead of your Str to your CMB should just be an additional benefit of Weapon Finesse?

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