Originally Posted by
wonkey
My opinion is that the OP isn't bad, but that kind of thing already exists in the game (blur, displacement, etc.). That, and a few other things, I think, make it harder than the already monumental task it would be to implement some of the other ideas mentioned in other threads.
Here's my personal favorite (quoted from part of a previous post of mine because I'm lazy):
A. Due to the nature of this game, a very high AC can be reached relatively easily.
B. Due to this being a D&D game, a D20 is used for attack rolls.
C. The higher the AC we are dealing with, the lower 20 is, as a percentage.
D. In order not to make maxed AC builds nigh invincible, the DMs have to scale monster to-hit to hit max AC.
E. In order that players without max attack bonus can hit ANYTHING, DMs have to scale monster AC to relatively low to-hit.
F. Without serious sacrifices that go beyond build decisions to simply gimping most everything else, getting within 20 AC of max AC is next to, if not absolutely, impossible.
G. For most players and monsters, therefore, AC is useless, and most players and monsters will hit just each other on a 2.
H. AC, which adds another element to the game, is largely irrelevant.
These are the realities of the brokenness of AC. The trick is to find a solution that is not too hard to implement, and won't cause nerd rage of epic proportions.
My personal favorite, for ease (relative term) of implementation, is to scale the die roll size (eg, from a D20 to a D30 at some point) as levels increase. In order to anger purists less than the inevitable storm, this can be done by granting all players and monsters feats that do this at certain levels (like heroic durability given to all players at level 1), in order to give a veneer of following the rules. This would accomplish the same thing. It would allow builds to not gimp themselves in other areas without falling off the dice. For example, if a D50 was used at max level, the devs could, say, scale the attack bonus to 5 points below max AC, so that max AC would be missed on anything but a 46-50. A build with AC 40 points below max would still get something, but a lot less.
Of course, making AC effective, for both players and monsters, would have to be balanced by such things as reducing healing effectiveness and adjusting attack rolls, which would cause a furor, but I think it would be a huge benefit.