In our party of 6 I am one of two Tanks and (mostly) have the highest AC of the group at a whopping 29 at 9th Level. (We don't really have any sort of buffing outside of Heroism, and Heals are scarce, so it's not a shock that it's very low.) This doesn't include Fighting Defensively or Total Defense (32 and 35 AC respectively).
I am a Mobile Fighter and use a Buckler (with a Two-Handed Weapon) and have (Greater) Shield Focus. The GM allowed me to spend a feat that I can retain Buckler AC while making attacks. With all of my current bonuses, my CMD is 32. (Another important note is that I have a base +15 at my highest BAB, +20 with everything active, so hitting won't be as big of an issue as I think it will be.)
My AC isn't as high as it should be (still need +2 Ring, +2 NA Amulet, and increased Enhancement Bonuses for my equipment just off the top of my head), and it will probably be that way for a while, considering my Saves are 11F/7R/6W. However, since a fair portion of what I am missing also applies to CMD, it has me worried about whether or not my AC will be my #1 number. (I believe Fighting Defensively and Total Defense applies to CMD as well.)
But is having a lower AC than CMD a bad thing? I'm given to understand that CMD is more wonky than AC in terms of scaling, and the fact that it's higher does appear to be better than the inverse; but this sort of thinking may lead me to getting hit a lot more than getting locked down, and since I don't have as much HP as the party Barbarian does (the other Tank), it's not something I should encourage.
What is the community's thoughts on this?
Lower AC than CMD isn't necessarily a bad thing, it just means that your progression of BAB + STR + DEX + SIZE has been faster than your AC.
If your party's damage output is high enough then your defenses become meaningless. Furthermore some of the most devastating abilities in the game tend to target touch or require a save to avoid, E.G. a Mhorg's tongue.
Lower AC than CMD isn't necessarily a bad thing, it just means that your progression of BAB + STR + DEX + SIZE has been faster than your AC.
If your party's damage output is high enough then your defenses become meaningless. Furthermore some of the most devastating abilities in the game tend to target touch or require a save to avoid, E.G. a Mhorg's tongue.
It is and it isn't.
It is in that we've had a boss fight where we've dealt over 1000 damage over the course (about 600 of it went to the Boss).
It isn't in that most of our encounters are generally 6+ rounds in length, and those are some of our lesser encounters.
I do have a lot of trouble increasing Touch AC as a Fighter, and yes, a lot of attacks affect Touch AC. Having a mere 15 at the level we're at makes me prone to getting hurt quite quickly. Sure, I have 3 Dex, 1 Dodge, and 1 Luck, but I'll need more methods to increase it.
Lower AC than CMD isn't necessarily a bad thing, it just means that your progression of BAB + STR + DEX + SIZE has been faster than your AC.
If your party's damage output is high enough then your defenses become meaningless. Furthermore some of the most devastating abilities in the game tend to target touch or require a save to avoid, E.G. a Mhorg's tongue.
[ . . . ]
It is in that we've had a boss fight where we've dealt over 1000 damage over the course (about 600 of it went to the Boss).
[ . . . .]
Yeah, but the only thing in Pathfinder official that could take that kind of punishment is probably CR20 or higher, so it stops really mattering.
So, here is the thing with AC:
If you have less than ([The average +to attack of monsters for that CR]+2)AC then there isn't any real reason to have AC that isn't entirely there for the special effects. This, of course, is saying if you have less AC for the average monster to hit you 90% of the time then there isn't a point on having AC since 5% chance to miss is the same if you have that AC or no AC.
As a fighter you should be going for only getting hit 25% of the time, so you need AC = (Average to hit + 15)
CR20 should be around +30 to hit, add 15 for 45 and you will be good the majority of the time. However, this is the average.
A gold dragon great wyrm has a +to hit of 38, even if the average is 33, hence meaning that your AC would need to be around 53 to get hit 25% of the time.
If you want to really dive into the meta then look at the averages, add 20, and try to have your AC around that since this will give you an AC that offers a 25% chance to get hit by enemies who are melee oriented. Just keep in mind that anything that targets touch is probably just going to go right through that.
It is almost impossible to become unhittable by enemies because if you have high AC then either your Touch or Flat will be poor unless you are playing a Monk who focuses on AC. Even then, however, it is likely that your CMD wont be very high, so enemies can still get you.
I think it is more important to have a high CMD since if you get pinned you cannot do anything to save yourself aside from trying to get out of the grapple.
Though, I'm sure there are going to be plenty who disagree, and that there is going to be some wizard who offers some sort of table or equation that answers all of your AC questions.