I am thinking that I want shields to be both a defensive weapon to be used to counter an enemys attacks (Parry) and also provide a form of protection/damage mitigation from attacks. I do not like the arbitrary ruling that a shield adds defense to arm+body only, as the body location hit by an attack is randomly determined and not affected by the targets actions (Ie, he can’t put his arm/shield first and choose to take the hit there, neither can he put his left foot to the rear to avoid hits there)
Neither do I want shields to just be extra armour that adds AP everywhere all the time. WFRP v1 did this, and it never sat well with me.
So I suggest the following: A shield-wielder may actively move his shield into position between him and an enemy/incoming attack by spending a reaction. The shield will now provide its AP vs that enemy/attack, but will NOT protect vs other enemies on that turn.
The chosen enemy will now have to attack through/past the shield, but no penalties will be applied. The reduced damage he will inflict as a result of the shields AP can be thought of as both the shield absorbing impacts, and as the attacker having to push an attack past/around the shield and delivering a lesser impact than he would have done otherwise.
This applies to melee and ranged attacks equally, you have to choose where the shield protects from. For ranged fire we could use a 30 degree arc like the flamer template to determine which attackers are covered by the shield. Keeping the protection up like this while moving requires the Tactical Advance Action.
As a variant I am thinking about letting this reaction be a Parry, where a successful Parry test works as normal. But even a failed test will let the shields AP apply towards damage taken, which will also be helpful if the Parry does not stop all attacks from a Lightning Attack, for example. The shield might not be positioned to protect against that opponents other weapon, if he dual-wields.
In this way, even an unskilled fighter can gain some protection by hunkering down behind his shield, at least if only fighting one opponent. A skilled opponent might use Feint to prevent the shield being deployed successfully against his attacks, but I think that the defensive bonuses a weapon grants to Parry should also apply to resist feints. Agree? Disagree? Why?
So, to summarize, and add some other elements I haven’t discussed:
1. Weapon craftsmanship WS bonus applies to all WS tests, including parries, Feints and other maneuvers.
2. You may position your shield to defend vs 1 Opponent/Attack with a Reaction/Parry. The shield will provide AP protection vs this attack.
3. Dual-wielding weapons give the ability to attack with both weapons as one Action, with a -20 modifier to both weapons (reduced to -10 with Ambidextrous). Therefore, it is only fair that dual-wielding (which includes sword+shield) also lets you parry with both as one Reaction. So if facing down a dual-wielding swordsman, you have the ability to defend against both his weapons. Position your shield/parry with shield vs one hand, and parry with your sword vs the other.
Different shields will have different AP values depending on make and material, and some might have Primitive AP.