Does losing Dex to AC also apply to CMD?

Question

Relevant rules:

CMD:

...Any penalties to a creature's AC also apply to its CMD. A flat-footed creature does not add its Dexterity bonus to its CMD...

blind:

...The creature cannot see. It takes a –2 penalty to Armor Class, loses its Dexterity bonus to AC (if any)...

penalty:

Penalties are numerical values that are subtracted from a check or statistical score. Penalties do not have a type and most penalties stack with one another...

Invisible:

...Invisible creatures are visually undetectable. An invisible creature gains a +2 bonus on attack rolls against sighted opponents, and ignores its opponents' Dexterity bonuses to AC (if any) ...

Bonus:

...Bonuses are numerical values that are added to checks and statistical scores. Most bonuses have a type, and as a general rule, bonuses of the same type are not cumulative (do not “stack”)—only the greater bonus granted applies...

The question is: Does losing your Dex bonus to AC mean you lose your Dex modifier which is factored into the CMD?

And as a side question:
Does losing your Dex bonus to AC mean you lose all dodge bonuses (not only the one from the Dodge feat, which explicitly states that you lose the benefits of that feat if you lose your Dex bonus to AC)?

My GM has the opinion that blinded creatures do not lose their Dex-bonus on CMD, because it is no penalty. He said:

...If it would apply in this case why are there multiple special rules which explicitly address the case where you lose your Dodge bonus to AC and in addition something applies which should be the normal rule in your interpretation.

For instance flat footed which explicitly mentions Dex bonus to CMD and the Dodge Feet which explicitly mentions that you lose the benefits from the Feat (1 Dodge bonus) when you lose Dex to AC.

Not the way I see it, penalties are clearly described as penalties in all descriptions ( –2 penalty to Armor Class), in addition the removal of a bonus is not a penalty in my opinion, it means a recalculation (without the called bonus)...

Is my GM right?

Answer 1

It depends on why Dex is denied, and also varies by interpretation.

When a creature is flat-footed, a creature is specifically denied its Dexterity bonus to its CMD (Combat Maneuver Defense).

Any penalties to a creature’s AC also apply to its CMD. A flat-footed creature does not add its Dexterity bonus to its CMD.

A flat-footed creature would also lose any Dodge bonus to its CMD:

Any situation or effect (except wearing armor) that negates a character’s Dexterity bonus also negates any dodge bonuses the character may have.

By comparison, the rules for the Blinded condition only specify a -2 AC penalty and losing Dexterity bonus to AC. There is no explicit mention of a penalty to CMD. The Pathfinder 1e Glossary has a specific definition for the term "penalty":

Penalties are numerical values that are subtracted from a check or statistical score.

By a strict RAW interpretation and Glossary definition, losing a bonus is not the defined as a penalty. By this logic, a Blinded creature takes a -2 penalty to AC and CMD, but does not lose its Dexterity and Dodge bonuses to CMD.

By a plain-English interpretation, losing one's Dexterity bonus is a form of being penalized. A player could calculate their character's flat-footed AC by subtracting their Dexterity bonus and Dodge bonuses from their normal AC. Additionally, it seems intuitive that if a Blinded creature is easier to hit with a weapon attack (i.e., their AC decreases), then they are also easier to hit with a maneuver (i.e, their CMD decreases by the same amount).

Answer 2

Probably intended to be Yes, but the rules as written say No

Flat-footed is a specific condition which happens to remove your Dexterity bonus to AC. Other conditions which also remove your Dexterity bonus to AC do not make you flat-footed.

A flat-footed creature does not add its Dexterity bonus to its CMD

This is very likely (in my opinion) intended, to mean that you lose your Dexterity bonus to CMD whenever you lose your Dexterity bonus to AC, but read as written it does not mean that.

Any penalties to a creature’s AC also apply to its CMD.

The word "penalty" is defined on page 12 of the Core Rulebook (sixth printing, July 2013).

Penalty: Penalties are numerical values that are subtracted from a check or statistical score. Penalties do not have a type and most penalties stack with one another.

Losing your Dexterity bonus to AC is not a penalty, and therefore this text has no effect in this situation.

Dodge bonuses to AC are discussed on page 179 of the Core Rulebook (same printing).

Dodge bonuses are denied whenever your Dexterity bonus is denied

Dodge Bonuses: Dodge bonuses represent actively avoiding blows. Any situation that denies you your Dexterity bonus also denies you dodge bonuses. (Wearing armor, however, does not limit these bonuses the way it limits a Dexterity bonus to AC.) Unlike most sorts of bonuses, dodge bonuses stack with each other.

Any situation that denies your your Dexterity bonus (in context: to AC) also denies you dodge bonuses. Therefore, all dodge bonuses to AC, from any source, are not applied whenever your Dexterity bonus to AC is denied for any reason.