RPG Mechanics...

So I’ve more-or-less got my stat system functional as I’d like for the moment. Now what I really have to do is decide how the stats should work together; particularly skills, attacks, and armor.

I prefer to work with a point-buy system because it’s so flexible and simple, but it also means that my decisions at this point are much more vital. I’ve based this little setup from many of my ideas on years of GURPS and D&D, and my preference for simplicity.

My primary stats are:
Health, Magic (Average end-game Health should be about 80.)
Strength, Dexterity, Wisdom (Basic human level is 10. Likewise, 20 is double, 5 is half.)

And a wide variety of skills that affect hidden stats and ability to do things.

Where I’m really stuck is figuring out how armor should work, how skills should progress, and how to determine attack power.

I suppose Attack Power would be the most important part. I hate the concept of a sword having power (unless it’s magical), so I suppose the logical thing would be to base it from the skill in question, any bonuses from Strength or Dexterity, and the ‘edge’ of the weapon used (strength of the fist, sharpness of the sword, weight of the hammer).

But how to play that into Armor? I’ve thought of a few ideas so far, but none I like. I could divide damage by the amount of armor, but that could be unreliable in terms of balance. I could subtract armor from the attack power, but that would render a character completely helpless against another, which is something I don’t want. I could also make armor add on to a player’s health, but it seems like a really odd concept to me.

What attack/defense systems have you used? Are you fond of any particular one?

Maybe just take a look at other RPG games how they do it, for example in WoW you can see the formula here: