View Full Version : Alternative AC system

2010-04-14, 08:08 PM
I really don't like the way AC works in 3.5. The fact that it doesn't scale to your character, at all, is very annoying. By level ten, a set of fullplate armor is woefully insufficient for turning aside blows, and you'll have to be dumpster diving for various bonuses to light your character up like a christmas tree just for a decent chance to avoid an attack.

The Class Defense Bonus variant in DMG2 is a good start, but it does the opposite of what's needed, since it's based on the bonuses you'd get from armor, armor scaling so slowly--and expensively--is the problem. So, alternative.

All classes have a Class Defense Bonus, but rather than being scaled against armor, it's scaled against the average attack of monsters, as shown here:


Each class has one of four progressions. The lowest progression is scaled so that a monster will, on average, hit on a 2 or higher. The highest progression is scaled so that a monster will hit on an average of 9 or higher. Class bonuses don't stack with armor, just use whichever is higher. If you're flatfooted or against a touch attack, you lose half your class bonus, though if you're both, you still only lose half.

For example, a wizard at levels 1-4 has a class bonus of 0. For those levels, his base 10 AC is enough. At level 5, he gets his first +1 bonus, since the average attack at that level is 8.5, rounded up to 9. With a +9 attack bonus, an enemy could hit an AC of 10 on a 1 if not for the critical failure rule. So by itself it's mostly useless, but combined with some dexterity or a ring of protection or whatnot, you can dodge some attacks. At level 10, average attack has gone all the way up to 15.5, so the bonus goes up as well, +8 for the wizard. His ring of protection and dexterity bonus still give him the same relative bonus.

So, obvious problem with this is that, at the higher levels, you can deck yourself out in buffs and whatnot and put your AC of the charts. So, second rule to go along with the class bonus: only apply your 4 highest modifiers to AC. So, a monk for example would at the higher levels use his natural AC bonus, class bonus, dexterity bonus, and something else, probably a ring of protection. Any extras on top of that wouldn't apply, assuming their bonus was lower.

Second problem, though a minor one I think, is Clerics. You'd think they'd get the fast progression because they have heavy armor proficiency, but combine that with a monk's belt and things are fubarred. So, they get bumped down to the lowest tier alongside the wizard.

I'm sure there are other exploits in this system, but those should be easy enough to deal with on a case by case basis.

So, thoughts?

2010-04-14, 08:22 PM