Armor Class against CR 20+ creatures

[shilsen]

Nonsense.

Try Sacred, Insight, and Luck bonuses to AC. That'll put you back into the "practically unhittable" range.

They're also not much of an option unless the campaign involves non-core and/or custom magic items, since the DMG doesn't have much in the way of items providing a Sacred, Insight and Luck bonus to AC.

Personally I do agree with NexH that one shouldn't aim for unhittable AC. What one should aim for is high enough AC that iterative attacks may miss, as may attacks made when the enemy is using Power Attack, Combat Expertise, etc.

 

[Sejs]

Also don't forget about concealment - goes a very long way to increasing your survivability in addition to your well-fortified AC.

Blur and Displacement are your friends.

 

[Elder-Basilisk]

They're also not much of an option unless the campaign involves non-core and/or custom magic items, since the DMG doesn't have much in the way of items providing a Sacred, Insight and Luck bonus to AC.

Rose prism ioun stone: +1 insight bonus to AC at a pretty affordable price.

Luck: Well, there are some pretty readily available bonuses in the spell compendium, but in the core rules you'd be stuck with the staff of power--not exactly affordable, readily available, or without opportunity cost.

Sacred: I think you are on to non-core rules there....

Also, note that you can do significantly better than the rogue in the mithral chain shirt with the +5 heavy shield. A fighter in mithral fullplate with a +5 tower shield, for instance gains three points on the rogue (as listed--it's really only two points because the original poster forgot to include +1 for small size). So, putting a halfling flighter in mithral fullplate with a tower shield gives AC 46. Add a rose prism ioun stone for AC 47. Now the +36 monster needs an 11 in order to hit. Add a ring of spell storing or other mechanism to get alter self and a troglodyte form could push that up to AC 53. The monster is only hitting on a 17 or better. Tack on a defending weapon, fighting defensively, or combat expertise, and a core rules character can become difficult to hit.

Of course, I wouldn't recommend shooting for unhittable characters either. It's simply less fun for the DM if he can't do anything that makes you worry about your character's health and doing so usually means either sacrificing offense (in which case, you might as well not be on the battlefield--you are ACTUALLY unhittable if you're not adventuring at all and it's not like you're doing the party much good by being mobile terrain) or sacrificing other defenses which means that on the few occasions that the DM's dice get hot, you will be in bad shape.

 

[Stalker0]

I also agree that the key at those levels is not to prevent all damage, but to level out the damage. If your AC is good enough that your only being hit on a certain percentage of attacks, then your cleric can keep you going, you can run away, etc.

Its the situation where the ogre barb fulls power attacks and hits you with all of his attacks, where suddenly you may be dead in a single round and no healing can save you, that what you want to avoid as much as possible.

 

[Beowolf]

i think that the intent of the original post might have been more of a complaint on that unless you spend all of your cash on defensive magic items its nearly impossible to achive a decen ac against high cr monsters. honestly what high level pc will have only rings of protection +5 and +5 armor and sheilds ect. none of its cheap and pcs wont want only armor increasing items. there have been plenty of suggestions to increase your ac but again it all depends on aquiring many expensive magic items. no pc will ever achive the 42 unless they were building to it for most of their adventuring careers let alone get everything else to get higher acs.

basicly its really hard to avoid getting hit by high cr monsters without going out of your way to get tones of treausure and find many different spells and have them active for the battle. sure you cant really belive in getting unhittable ac but even a reasonable chance with the 42 takes a lot from other areas of your charachters abilities and wealth. what happens when the halfling gets attacked by a spell that dosent need to hit ac?

 

[Legildur]

I disagree (that you need spend all your wealth on defensive items to achieve a reasonable AC). I currently play a elf paladin/fighter in a PbEM game where the items are generally found, and rarely bought. This has lead to some less than optimal wealth and equipment distributions compared to building a high level character from scratch.

Now, at 14th level, the character has a base AC of 30 (+7 breastplate, +5 buckler, +1 ring, +1 amulet, +5 Dex, +1 Dodge feat) and a +26 attack bonus. But he can quickly ramp up his AC to 38 with Combat Expertise and Fighting Defensively (bought 5 cross-class ranks in Tumble). Obviously there is significant room for improvement on the equipment side, but future feat plans include Divine Shield (Complete Warrior) for an extra 4 points of shield bonus, Improved Combat Expertise (Complete Warrior) for the added flexibility of punching it through to AC 49 (or thereabouts) and still having a reasonably effective attack bonus of +11 for Whirlwind Attack duties.

When you start talking about +5 rings, +5 armor, +5 amulets, ioun stones etc, it starts to get pretty crazy pretty quick. About half my character's wealth is in defensive items, the rest is in weapons.

 

[Rkhet]

If you're a fighter type, take a level of magic-domain cleric and use a scroll of Shapechange. Or UMD it for the rogues. The right forms will get you awsome natural AC, among other things.

 

[Magesmiley]

A couple more which weren't mentioned (and wouldn't help the halfling, but could help the fighter):

Heavy Armor Optimization and Improved Heavy Armor Optimization (+1 each) (ROS)
If you're a dwarf, you can take the 8th level dwarf fighter substitution for another +1 (ROS)

ROS also has battle plate and mountain plate which are 1 and 2 points higher on AC respectively than full plate.

PHB2 has a feat which increases shield bonus by +1 as well if I recall.

There are also some prestige classes (such as dwarven defender) which increase your AC too.

 

[dagger]

Thats another reason you are starting to see Karmic Strike builds, because if you are going to get hit, might as well hit back (plus your normal attacks).

 

[Stalker0]

another thing to keep in mind is your not always going to face creatures equal to your CR, you will often face creatures lower than it. In fact, "realistically" the higher in level you are the more opponents you should face at a CR lower than your level. Those opponents will not have as high attack bonuses, meaning you may be very hard to hit against them.

If your near impossible to hit at a CR equal to you, you'll be virtually impossible to hit by anything lower.