Improving the shield rules old and new

I don't need to explain that pretty much everyone knows by know that shields are not treated very well in any edition of the D&D rules. At least until Late 2e (Skills and Powers) shields have been chronically underrated.

Its an unfortunate legacy rule that leaves these supremely effective protective devices that have been in near constant use for at least 4000 years in the cold and yet the rules we use, old and new often treat them as poor siblings.

Whats needed are a few changes, nothing too complex to give them the oomph they need

1st, consider Trollsmyth's excellent Shields will be Splintered Rule. This is a lot of fun a very simple.

2nd you might try this

Shield fall into 3 general types (I am ignoring the 3x tower shield here)

Buckler, a hand carried shield about the size of a large hat, 12" in diameter or so . Its small, may be used as an offhand weapon but may not bash or rush . Its also grants +1/-1 to AC.

Shield, this is the medium sized shield akin to a Rondel, a Targe or the like. Its twice the diameter of a buckler and weighs about 5 lbs or so. Its is unpleasant to carry however and unlike a buckler (which can be conveniently hung at a belt) this type of shield needs to be stowed and can easily get in the way in a dungeon or urban environment. Its gets +2/-2 to AC. It may shield bash or rush.

Large Shield. Knight shields, Hoplite Shields and Viking shields are all of this type. These are heavy, 10 lbs or so, 3 feet in diameter and fatiguing to carry. Great on a battle field, suck in a dungeon. They grant +3/-3 to AC and may shield bash or rush as well

In addition any shield user may elect to use the shield defensively, reducing the to hit roll by up to the shields non magic bonus and adding to AC.

Bucklers also have the extra ability to drop their own +1 bonus and reduce the opponents AC by this amount.

With these rules you can restore the effectiveness of shields to something approaching historical norms without unbalancing the game.