Recently there was some discussion about shields in D&D. They don't really pack the punch in the game as they do in real life. And that's a shame. So, the most cheered solution was a reshuffled Armor Class table (thanks J.D. & Stuart). One where shields are more useful. A solution which rather resembles using the existing “weapons vs. armor” modifier list in AD&D, as Nagora noted. You know, the table which nobody ever uses or looks at because “it's too complicated”? Gygax has the last laugh again, I guess.
But, apart from me being less happy with forementioned shuffle solution than most – I don't play D&D – it's not the only game where shields suffer. My game in practice also lacks shield use. One commenter rightly noted that he'd seen more shields in D&D than in DD2 – albeit it many magickal shields. So, I figured it time to rethink, or at least restate the shield rules in my game too.
Shields in Dark Dungeon
Blocking with Shields
Those using a shield may use it to block or deflect blows from from weapons, making a succesful roll on their shield skill. Bucklers gain a +1, small shields a +2, large shields a +3 on blocking attacks. The shield is trained as a second hand weapon, which means that you may block a blow with the one hand, and attack with the other hand in the same round without penalty.
Attacking with Shields
Shields may also be used to attack, if they are not used for defense in the same round. Spiked shields are weapon class 1, other shields class 0. You may add your shield skill to your shield attack as with normal weapons, but not the special shield bonus.
Drawbacks of Shields
Large shields are bulky, and impair movement and dexterity checks. Large shields can only be used in conjunction with a short sword or similar shorter weapon. Medium (or small shields) with nothing larger than a longsword. Bucklers may be strapped to the arm, and be used with a hand-and-a-half weapon. Twohanded weapons cannot be wielded with shields. Lances, javelins and spears can be used with any shield.
Shields may be purposely destroyed with a succesful special attack (12+) of a heavier weapon (a heavier weapon class). Wooden and wicker shields are armor class 1, reinforced shields armor class 2, steel bucklers and hoplite shields 3. So wooden shields can be hacked with an axe of class 2, reinforced shields with a bastard sword of class 3, and so on. Fumbling on your shield roll will also break it.
Shields as Missile Cover
Shields may be used as cover against missiles, especially if used in a shield wall. I haven't quite figured how to simulate this effect best, but you might give a -3 on missile attacks vs a shield wall, and -6 against a testudo formation (“tortoise” with shields both in front, side and above the formation).
Testudo Formation photo by Neil Carey, from Wiki Commons