OK. I'm gonna start with defenses because it's something that I'm battling with and I think I need to "think" out loud in order to get anywhere. But before we get to defenses, I'm going to talk about attack bonuses.
Just stay with me.
One of the things I'm pretty set on doing is changing the class's Base-to-Hit bonuses to Combat Skill.
This is more than just a nomenclature change. I love the idea that, as you gain levels and increase your combat ability, your ability to defend yourself goes up as well. So, (keeping AC as it is in FH&W) the formula would be:
AC = 10 + Armor + Dexterity mod + CS + Shield + Misc
Now, I'm pretty happy with the idea of removing your ability modifier from your AC as it should really be about training, not about your Dexterity.
But what about my thief who needs his dexterity modifier in order to be competative? Don't care. Thieves aren't trained fighters. Fighters are. A fighter should be able to defend himself better than any other class.
But what about reflecting natural aptitude for combat? That is done by the very fact of having a class. Every class has requirements that need to be met in order to be them. Congratulations. You have the natural aptitude for being whatever class you qualify for. NPC's have a slightly "lesser" version of the four main types of classes (Fighters, Rogues, Magic-Users, and Divines). This represents all those people in the world that are better than level 0, but don't quite have what it takes to be extraordinary.
That leaves us with the formula of:
AC = 10 + Armor + Combat Skill + Shield + Misc
That's not terrible. Basically the same as it was before, but now your AC goes up as you level. But a fighter will have a better AC than any other class at higher levels, regardless of what armor he wears. That's a good thing.
Now here's the problem.
There's already a mechanic that kind of takes this into account. Hit Points. Every level you gain more hit points and that can represent your ability to better defend yourself (among other things). So I don't know if I want to double up on your class "defense". Maybe it's not that big of a deal, all things being equal.
Lets take a look at the various classes at levels 1, 3, 5, and 10 and we'll assume Warrior with chain (5 by the book) and a shield (1 for medium) (Base AC 16), Divine with chain (Base 15), Rogues with leather (Base 12), and Magic-users with none (Base 10)
Level 1 - Warriors 1 (17), Divines 0 (15), Rogues 0 (12), Magic-Users 0 (10).
Warrior only has a slight advantage, but being combaty types, that's not a bad thing.
Level 3 - Warriors 3 (19), Divines 1 (16), Rogues 1 (13), Magic-Users 1 (11).
Warriors start to pull away a little bit more, but they're not out of the realm of reasonable. But, you'd really only want to send another warrior type in after a warrior with chain and shield. Which was pretty much true at level 1, but quite a bit more-so now. Rogues pretty much need back attacks (or my version of the "gang-up" rules I'll get into in a later post) and Divines are gonna need to get lucky.
Level 5 - Warriors 5 (21), Divines 3 (18), Rogues 3 (15), Magic Users 1 (11)
Level 10 - Warriors 10 (26), Divines 6 (21), Rogues 6 (18), Magic Users 3 (13)
Hrmm....now that I've written that out, that doesn't really work. Rogues and Divines need a natural 20 to hit.
Interesting experiment. Back to the drawing board...