It's simple: Use your regular combat rules system, but state that plate is proof of anything less than an axe or pole arm. You cna strike it, but the only blows that count are those to lesser armour points. If you wear a full-face helm, congrats, you are proof. Plate legs ditto. My buddy fights in cap a pie plate. I can only tag him in the armpits, groin, or the back of this legs.
Fun, fun. It's _amazing_ the difference good -- or even so-so, in my case -- half-sword technique can make. Suddenly, those medieval illustrations start to make sense.
Give it a try, I think you will enjoy it (but take care with those groin shots).
