At what rate should AC prices increase?

[SangoProduction]

As is pretty well-known, prices for increasing AC just becomes impractical in 3.5 and PF at high levels. So, at what price point does it become a decent defensive investment without just becoming so cheap that it's ubiquitous? And what if miss chance items gained an additional 10% to their item cost?


Here is the current price point in PF and 3.5.

Armor bonus (enhancement) Bonus squared × 1,000 gp
AC bonus (deflection) Bonus squared × 2,000 gp
Natural armor bonus (enhancement) Bonus squared × 2,000 gp
AC bonus (other) Bonus squared × 2,500 gp

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PF even rounded out the wealth numbers which resulted in a slight increase to character wealth by level. Which is actually worth about a level more wealth past 10th level.

[Venger]

as we're discussing in greater detail here (http://www.giantitp.com/forums/showthread.php?560919-So-how-much-AC-do-you-*need*) unless you invest heavily in ac to become unhittable, like an abjurant champion, it's not really worth it to allocate resources to ac since monsters' to-hit scales much more quickly than you can boost your ac. don't punish characters for using miss chance.

[SangoProduction]

Yes. I acknowledge that the usage of AC is impractical. Ideally, this is not the case. So I was asking how to fix the scaling price of AC.

[Lans]

I would make natural armor cost the same as a base armor enhancement, and from there drop the price down 20-30% across the board.

[zlefin]

it's probably better to create another way to boost AC, then adjust accordingly.
If you want to experiment: I'd recommend adding some fraction of BAB from class levels as a dodge bonus to AC, then see how close that gets you, and adjust from there.

[ericgrau]

They already are cheap and already do keep up. With a reasonable budget most primary attacks will miss at all levels and all or the vast majority of secondary attacks will miss. Secondaries are important because they mean even if you are behind in AC or are a low AC class, there's still a reason to invest a little into AC. Miss chance items are already extremely expensive and not worth getting until level 15++. Many people just don't know how to select AC items well. You need to spread out to multiple sources to get a good deal.

As for a discount, if you make them much cheaper you run the risk of many people becoming unhittable except on the roll of a 20. But if your gaming group is playing with many of the better items from the magic item compendium, then it may be a good idea to give a discount to AC. About 25-50%. The problem there is that then you need to go back and reprice all other items too. It would be simpler to instead increase the price of the very best items from MIC. And if you think that's too mean and want to give players more toys, increase treasure/WBL instead. OTOH if you think AC items aren't getting enough attention at your table, first explain how to spread out your AC items and 2nd consider a discount of 10-20%, as with anything else.

Spread out to: armor, shield, natural armor, deflection, insight (ioun stone). Eventually dex. Consider that many can use a mithril buckler without proficiency or penalty (no loss to attack rolls, no spell failure), such as rogues and casters. At higher level get mithril armor or celestial armor. Short AC buffs are too short. Hour/level buffs are nice for back liners and sometimes front liners, but if you're a front liner then items are cheap enough and scale faster than the buffs.

Now for the reasoning. There's a lot of math involved but I have run a bunch of numbers on core builds and it does scale 1 for 1 against monster attack bonus at all levels. Even when I set the computer programs to make 25-50% of monster attacks non-AC attacks it put a pretty good chunk into AC. If anything a lot of non-AC attacks means to invest more in saves, touch AC (if the attacks merely bypass armor), SR, & etc. But basically +1 AC tends to be equal to about 10% miss chance. Because typically the monster needs to roll an 11 instead of a 10, and so it's the same as having 10% of his hits negated. Against secondary attacks or on someone who already has a high AC, it's even better than 10%. Many people get confused because they use bad math, but that's all there is to it. Permanent 20% miss chance is far more expensive than +2 AC until super high level, and action activated miss chance burns a precious action so that cost usually isn't worth it.