As was previously stated you should cover vulnerable spots like the head, knees and elbows, kidneys, neck, and of course the groin. Thats all i used in the sca. You'l get some good welts but as long as the v spots are covered well you should have no problems.
LOL you must not be anywhere near the Kingdom of Atlantia. They are a bunch of rhinohides down here so either they have too much armor on or have developed iron skin.