The AC of my character is falling far behind her other defenses, and I'm wondering if I have missed out on something basic and important. I am going to post some of her stats as an example to this question.
AC in general
The armor class of a character is basically determined by: 10 + ½ level and if the armor is magical.
The class of a character and feats can improve the AC as well, depending on what a player choices to play.
You can improve Will, Reflex and Fortitude through a lot of item slots on the sheet.
Is a magic armor the only way to improve your AC through items?
I am aware of the Armor Specialization feat (which removes penalties and provides +1 to AC) and that you can purchase fey material armor which would give an additional +1 to AC.
What other ways of improving AC am I missing?
The Leader role
My level 24, melee Revenant Ardent has an AC of 32, Fortitude of 35, Reflex of 37 and Will of 37. She wears leather +5 Displacer armor. Her ability scores are Strength 15, Constitution 20, Dexterity 13, Intelligence 16, Wisdom 14, Charisma 24.
To start with I was wearing Hide, but then I decided that I wanted Gambit armor. And Gambit armor only comes in cloth or leather. The property is good for my character because she does a ton of damage when she crits, and that's what I built her for. The reason why I have a Displacer armor instead, is I did not update my item wishlist in time, so my DM ended up using my old wishlist instead.
The other players in my group have far superior defenses for some reason.
As an example: The tank does not get hit with 44 against his AC. That of course includes temporary boosts to AC, but it is still way ahead of my defenses, hence the problem: I get hit by monsters at this level by rolls between 3 and 5.
I have run into this low AC problem before with a Shaman character as well.
Are Leaders just not made for close combat?
Best Answer
Don't pretend you're a rogue, because Ardents don't look good in leather. You require some real (and exotic) metals between you and the enemy. The thicker, the better. Ask for some mirrored or hydra layered plate platemail +5, as it's in a similar theme to your original gambit armor.
Item materials are also important and scale by half-tier1, but your main problem is that you're in leather armor with a dex of 16... in epic. The choice between heavy and light armor becomes critical.
Ardents use heavy armours because they, typically, don't invest in being fast or thinky. Furthermore, alternative materials don't cost more, only the enchantment matters.
The calculation should be 10 + half-level + material&type + enchantment + feats + ability score if light armor.
Displacer armor is for cloth leather or hide. Looking at the Ardent Handbook, you should be in heavy armor, not light armor.
Given that you're using leather, you should be using Anathema Leather or equivalent (adventurer's vault) to give you an extra +3. However, you're an ardent. No ardent should be focusing on int or dex, and ardents don't get off-stat bonuses to light armor.
Displacer Anathema Leather Armor brings your AC to 10+24/2+5+3+3 = 33.
Assuming you stay in chain, taking the boring Veteran's chain, in the +5 version, we get a Veteran's Weavemail Armor +5 +5 enchantment, +10 from the weavemail. or +15 from the armor. 10+24/2+5+10 = 37, which for a shieldless leader designed to be in the second rank... is not horrible.
Assuming you invest a few of your feats into AC (which is only reasonable, considering that you're in melee with a con focus), You'll be in nagascale scale armor (+11 armor bonus) for a 38. And since you've got a 15 strength, you should have jumped into plate into epic, and +5 layered plate (+12 from armor). Add in armor specialization from paragon for a +1, and you've got a neat 40 AC.
Enemies, at level 24, should have around a +28 to hit. They will have approximately a 38 AC.
Additionally, you need to give enemies a strong incentive not to attack you or be next to you. You should have, as your at-wills, Unsteadying Rebuke and Violent Upsurge. Make it clear to the first enemy who attacks you that a) they'll get slid to the bad place on their turn, and b) they'll have all sorts of bad bad vulnerabilities. While it doesn't make up for your barely-there leather, it at least acts as a very vocal discouragement to attacking you. Which, when combined with demoralizing strike means that enemies will think twice before getting near the scary scary scary person. (Or, y'know, try to focus fire you down and kill you.) An AoE of "Here, have -6 to defenses" combined with an immediate reaction slide will inspire great fear in the DM.
1According to Andras, Heroes of the Fallen Lands, page 325, has eliminated that requirement entirely, and just automatically scales armor by tier. Take this as another reason to be using the character builder to generate your character sheet.