Do you want some better AC with that experience?

[Winterthorn]

Hi, this may have been done by others before, but I wanted to share this house tweak on AC for feedback.

I have a house rule in my campaign that PC heros receive a bonus to their AC equal to 1/2 their total BAB (rounded down). Thus, for example, a 10th-lvl Sorcereress would have an additional +2 (+5/2 = +2) to her AC due to experience earned, while her 6th-lvl Fighter/4th-lvl Rogue ally would have an additional +4 (+6 plus +3, all divided by 2 = +9/2 = +4).

This modest bonus is in addition to the usual sources of improving it.

A friend of mine asked why BAB gets better with XP but AC does not. We discussed this and he suggested tying a gradual improvement to AC to how BAB improves - it would be easy to remember and easy to calculate for multiclassed PCs.

I had some rules considerations to make though. I decided that unlike a dodge bonus to AC, this bonus was always "on" as long as the PC was conscious and able to move. So experienced PCs are a little less vulnerable when flat-footed than their newbie peers. I guess one could say it is sort of a 6th sense to AC derived from all that combat experience. Because it is tied to BAB, low level charcters hardly notice the benefit, but that 20th-lvl Fighter will be really happy to charge into a fight with an extra 10 to his AC! A 20th-lvl Wizard would have an extra +5 to his AC which could be useful but not essential in most circumstances. In fact this little extra to AC may help non-spellcasting characters to keep up a bit better with the spell power of casters - it could be particularly good for warrior-types dealing with all those summoned monsters coming from the enemy!

By the way I have used this tweak for a number of months and it seems everyone in my camapign likes it. As a DM I'm fine with it as I am a tad stingy on handing out magical armour and weapons. Additionally my players are the kind to favour mobility in battle, very much like many action scenes in films, and so the AC boost permits lighter armour and hence fewer movement restrictions! If ever I feel things get wonky and too easy for player's, I have many subtle means as DM to amp up the challenge for players So far so good though

The only thing I'm not sure about is whether I should qualify this bonus as a competence bonus, or an insight bonus, or create a new bonus type called experience bonus (which seems a little overdone IMO). Or simply leave the bonus unqualified. No rules quandry has occurred in game yet where I have to make such a call.

Thoughts and feedback?

 

[Griffith Dragonlake]

Check out the Defense Bonus from Unearthed Arcana:
http://www.d20srd.org/srd/variant/adventuring/defenseBonus.htm

This is basically the same system used in d20 Modern.

 

[Arkhandus]

Yep. Your version is basically like that of D20 Modern, where each class gets a class defense bonus (AC is called Defense in D20 Modern) based on their level. Though in D20M it is not at all tied to BAB, but completely separate. D20 Modern's class defense bonus is also always "on", even when flat-footed or the like. Your version is probably fine, since it doesn't give such significant AC bonuses as D20 Modern's Defense bonuses (which are there to compensate for a lack of magic items and common armor; hardly anyone in the modern day wears body armor, unless they're a cop or soldier on duty).

 

[Aust Diamondew]

I've used a very similar house rule, but only in low magic item games.

If you use the standard amount of magic items in addition to giving a class based AC bonus (that stacks with everything) then ACs will start to get too high. So as long as you keep being stingy with those AC boosting magic items should be fine.

One thing I did in my game was that you loose half of the level based AC bonus when flat footed or against touch attacks. It was simply an unamed AC bonus.

 

[Winterthorn]

Thanks folks. I'll be checking out UA and the d20 Modern rules for comparison since I hadn't looked at either for a while.

 

[Quartz]

I like it. It's nice and simple and tied to combat prowess as it should be in D&D. Stolen!

 

[Aus_Snow]

Thoughts and feedback?

Sounds exactly like [part of] my long-time house rules for this very issue, in 3e.

But no, it is definitely *not* the same as that UA rules variant. I personally don't care for that one, but of course YMMV.


Notes:

* I use armour as DR (pure, not half/half like in UA). More like the Conan system, in some ways. This means (apart from anything else) that armour doesn't throw Defence out of whack entirely. Magical armour still adds its enhancement bonus to AC (i.e., Defence). No problem.

* I also subtract whatever a monster gains in Base Defence Bonus (i.e., half their BAB) from among their inherent AC bonuses (like Natural Armour, or Deflection). Usually I divide it pretty evenly, but in some cases I don't agree with how the monster was "AC'd up" in the first place, so might take it all from the old Deflection bonus, for instance. Either way, doing this helps a great deal by instantly rebalancing critters. [Never mind the weird version I posted here previously - got my wires crossed. ].