Is AC passé?

[GhengisConrad]

So, take a look at my build, in my sig. Consider that I am building for my personal style of play (also in my sig).

But, also, in general optimization/arena style play...

is AC old-fashioned? Do people not use it?

I twist a bit to pick up my con bonus to AC through Fist of the Forest. I am a half-minotaur feral anthro bat, so my con is pretty high. Also dex, and I get like a +8 to my natural armor.

Throw in a ring or bracer of magic sheild of or mage armor or what have you... I've got some decent AC.

Is this something to look forward to as useful? Or do most high level things really not even use AC? And if not, what is the cheapest (fewest dips, feats invested, whathaveyou) way to obtain relevantly decent defenses?

[Emperor Tippy]

AC is only all that great within a relatively narrow range. If your AC is low enough that your enemies will only miss on a natural 1 then any AC at all is a waste. If your AC is high enough that your enemies will miss on a 19 then any more AC is a waste.

Generally AC equal to 10+2xECL is good enough 95% of the time and can fairly often be had for little investment.

AC equal to 10+ECL is about the minimum you want, if you aren't willing to invest enough to hit that point then you are generally better off investing nothing.

AC equal to 10+3xECL is generally about the maximum you want, anything more than this is just totally wasted.

[GhengisConrad]

Howabout touch AC?

[TuggyNE]

AC is only all that great within a relatively narrow range. If your AC is low enough that your enemies will only miss on a natural 1 then any AC at all is a waste. If your AC is high enough that your enemies will miss on a 19 then any more AC is a waste.

Two addenda: first, increasing touch AC is generally more profitable (since there are fewer and smaller bonuses to touch attacks most of the time), and second, AC below hit-on-a-2 range can still be helpful for limiting enemy Power Attack if they aren't using Shock Trooper (either because they're low- to mid-op foes, or because you prevented them from charging). It's only when your AC is so low that they can hit you on a 2 at full Power Attack that it is, strictly speaking, utterly wasted.

[GhengisConrad]

I mean, if I am looking for 10+3xECL AC, what kind of touch AC should I be looking for?

[Particle_Man]

Two addenda: first, increasing touch AC is generally more profitable (since there are fewer and smaller bonuses to touch attacks most of the time), and second, AC below hit-on-a-2 range can still be helpful for limiting enemy Power Attack if they aren't using Shock Trooper (either because they're low- to mid-op foes, or because you prevented them from charging). It's only when your AC is so low that they can hit you on a 2 at full Power Attack that it is, strictly speaking, utterly wasted.

Also, iterative attacks might miss, even if the first one hits on a 2.

[eggynack]

Two addenda: first, increasing touch AC is generally more profitable (since there are fewer and smaller bonuses to touch attacks most of the time), and second, AC below hit-on-a-2 range can still be helpful for limiting enemy Power Attack if they aren't using Shock Trooper (either because they're low- to mid-op foes, or because you prevented them from charging). It's only when your AC is so low that they can hit you on a 2 at full Power Attack that it is, strictly speaking, utterly wasted.
Also, because touch AC is so hard to boost, it means that people really like to target it. Sometimes with really dangerous stuff too, like orbs and rays. It's a pretty good thing to boost for that reason.

[zlefin]

is there a good way to make a diminishing returns mechanic for ac? Some system tweak so that it's always relevant if you're ac is higher/lower, but isn't too hard to calculate during play?

[icefractal]

Also, because touch AC is so hard to boost, it means that people really like to target it. Sometimes with really dangerous stuff too, like orbs and rays. It's a pretty good thing to boost for that reason.And/or, get some Ray Deflection going. Doesn't stop every touch attack, but it stops a lot of them cold. Description is a bit vague on whether it affects "ranged touch attacks", or just rays. In the former case, combine it with being hard to get close to, and you've got a nice defense going.

[Psyren]

Also, iterative attacks might miss, even if the first one hits on a 2.

This bears repeating. Even if their first attack is guaranteed to hit you, that doesn't necessarily mean your AC is wasted - every iterative that misses can be compared to 25% damage reduction.

[Gadora]

AC is only all that great within a relatively narrow range. If your AC is low enough that your enemies will only miss on a natural 1 then any AC at all is a waste. If your AC is high enough that your enemies will miss on a 19 then any more AC is a waste.

Generally AC equal to 10+2xECL is good enough 95% of the time and can fairly often be had for little investment.

AC equal to 10+ECL is about the minimum you want, if you aren't willing to invest enough to hit that point then you are generally better off investing nothing.

AC equal to 10+3xECL is generally about the maximum you want, anything more than this is just totally wasted.

At what level does this rule of thumb kick in? Because a level one with AC 14 is absolutely not wasting investment.

[Gemini476]

Also, iterative attacks might miss, even if the first one hits on a 2.

If they hit you on a 2 with a full power attack, you might not need to worry about iteratives.

After all, your HP is HD+level*HD/2+level*Con. Power Attack starts at HD+Str and ends somewhere at N*level+1,5*Str. You're screwed if N is half your Hit Die and 0,5Str is half your first hit die, assuming that Con and Str are equal. Which they probably aren't.

[Kelb_Panthera]

The standard AC the game expects you to have is roughly equal to 13 +ECL.

As to the question the thread is premised on; no, AC is not Passe. It has its place just like any other layer of defense. Miss chances are -better- but only contribute to your overall chance of avoiding damage on a given attack.

Touch AC should be as high as you can reasonably get it since touch attacks are usually made to deliver some really nasty stuff. Exactly how high is acceptable is dependent on how frequently you expect it to be targeted compared to your full AC.

[sleepyphoenixx]

It's not like AC and touch AC are always seperate. The more boni you get that affect both the better.
In general touch AC doesn't need to be quite as high since touch attacks are usually made with lower to hit so if you use dodge, deflection and similar stuff to boost your AC your touch AC should be fine.

[NichG]

is there a good way to make a diminishing returns mechanic for ac? Some system tweak so that it's always relevant if you're ac is higher/lower, but isn't too hard to calculate during play?


Iterative attacks are supposed to be the diminishing returns mechanic for AC. The problem is that generally you've messed up if enemies are getting full attacks off on you, and lots of multi-attack sources don't have diminishing iteratives. Furthermore, a lot of the time you're going to care more about the things that don't tend to be iterative (rays) than full attack iteratives.

I can think of a few other systems one could use but I think they'd generally require a lot of legwork in D&D. Probably the easiest would be something like:

- If an attack roll hits double your AC, that counts as an automatic crit threat.
- If an attack roll misses half your AC, you get an attack of opportunity against the attacker, which can you can take with a ranged weapon if available.

This would expand the viable range by quite a bit and really penalize 'my AC is low enough that I just won't bother'. Of course this opens up the door further to infinite crit-chain builds.

[Rubik]

The last time I made a martial character (http://www.giantitp.com/forums/showthread.php?p=15474863#post15474863), I substituted hardness, miss chances, invisibility (and an Invisible Spell'd Solid Fog to prevent True Seeing, et al), and shapeshifting immunities for AC. It worked rather well.

[Invader]

Again I think its important to mention that the amount of AC you need is highly dependent on your campaign. Within the playground AC is generally seen as a subpar investment but in most average non super optimized games AC serves the exact purpose its supposed to and makes you get hit less. The same can be said for healing and any number of other things people say aren't any good.

[Psyren]

Again I think its important to mention that the amount of AC you need is highly dependent on your campaign. Within the playground AC is generally seen as a subpar investment but in most average non super optimized games AC serves the exact purpose its supposed to and makes you get hit less. The same can be said for healing and any number of other things people say aren't any good.

What I've learned in the years I've been on this and other D&D forums is that they tend to assume a very RAW-focused high-powered approach to the game. Very few DMs I've played with at actual tables run the sort of games assumed here. And very frequently, we end up needing (or at least strongly benefiting from) things like high AC and in-combat healing that are considered wastes of time here.

[Scow2]

Iterative attacks are supposed to be the diminishing returns mechanic for AC. The problem is that generally you've messed up if enemies are getting full attacks off on you, and lots of multi-attack sources don't have diminishing iteratives. Furthermore, a lot of the time you're going to care more about the things that don't tend to be iterative (rays) than full attack iteratives.

I can think of a few other systems one could use but I think they'd generally require a lot of legwork in D&D. Probably the easiest would be something like:

- If an attack roll hits double your AC, that counts as an automatic crit threat.
- If an attack roll misses half your AC, you get an attack of opportunity against the attacker, which can you can take with a ranged weapon if available.

This would expand the viable range by quite a bit and really penalize 'my AC is low enough that I just won't bother'. Of course this opens up the door further to infinite crit-chain builds.I'd use "Twenty Higher/lower" rather than Double/Half.

[NichG]

I'd use "Twenty Higher/lower" rather than Double/Half.

Yeah, I guess if you can't even hit someone's AC on a 20, you wouldn't generally bother attacking them that way anyhow, so the AoO thing would get un-used at the high end (enemy has 140 AC, we have 100 to-hit, lets not use attack rolls)