>Nobody is going to try to swing their weapon AT your shield.

Sure they are. Oh, certainly, not at the center, but at least some of the time they'll try for spots near the edge -- and what with the fact that you're moving, your shield is moving (it's strapped to your arm, so you've got some good leverage), and they're moving.

If you've got a big shield, you can twist your body to avoid a blow and duck behind it. If you've got a small shield that's less likely, but also less likely is loss of strength or broken wrist to prevent you from moving it.

>Think about it. Are you going to walk up with your sword and
>start beating on a guy's shield if you're trying to kill them?
> That's like a boxer punching his opponent's gloves that are
>hanging around his stomach. I'll give you the -AC for the
>shield even with low strength, as it is still armor, but the
>shield block skill could feasibly become ineffective at some
>point.

Conceivably, sure. But shields -- especially big shields -- doen't have to move anywhere near as fast as a weapon to be effective.

That said, there is a certain amount of "real life cause" for a stronger person to have an advantage over a weaker person when blocking with a sheild. In game, though, I think that's mostly handled with classes ability with the skill.