I still like the idea of the shield bash. There's no reason you can't use it for both offense and defense. I was thinking that Parry would be an inate ability. Just as all weapons come with a Damage rating, they'd all have an Armour rating too. They could start with a 5% Chance To Block and increase with training. Same for the shield; it should incresae it's chance to block with training.
What if the chances were changed to:
Body: 20%-30% (depending on size)
Legs: 10%
Feet: 5%
Hands: 5%
Shield: 10%-20% (depending on size)
Weapon: 0%-10% (depending on difficulty)
TOTAL: 80% maximum chance to block any one hit, assuming full equipment.
You could train your weapon or shield up to 20% and 30% respectively with <Weapon> Expertise, making a total of 100% chance to block any one hit. Now bigger armour is a lot better!
I don't think there should be a separate Parry skill. The Armour rating of a weapon should go up with the <Weapon> Expertise. Parrying with a sword is very different to parrying with a staff.
There's no reason you can't parry with a shield or with a two-handed weapon. A two-handed axe would have an abismal Armour rating anyway because it's too difficult to manuveur. Some weapons could even have an Armour rating of zero.
Have a look at the arcade game (also on console) Soul Calibre for some interesting medieval combat.
