
Random Joe |

You only get attacks of opportunity against squares that you threaten, and you only threaten squares that you can attack. If you're hiding behind a shield for a round, you aren't attacking - you've taken a full defense action for a round. You couldn't make any fewer attacks of opportunity if you were unconscious.
Facade, your DM is right that only the shield bearer gets *total cover* from his shield, but anybody behind him should get the +4 AC soft cover bonus. Of course, if you're directly behind him, you get the soft cover regardless of whether or not he's hiding behind his shield. His body will stop an arrow just as easily as his shield will, as far as you are concerned. The shield is mostly for his own survival, unless your group is really into teamwork feats.
- JR