Sunder
You can use a melee attack with a slashing or bludgeoning weapon to strike a weapon or shield that your opponent is holding. If you’re attempting to sunder a weapon or shield, follow the steps outlined here. (Attacking held objects other than weapons or shields is covered below.)
Step 1
Attack of Opportunity. You provoke an attack of opportunity from the target whose weapon or shield you are trying to sunder. (If you have the Improved Sunder feat, you don’t incur an attack of opportunity for making the attempt.)
Step 2
Opposed Rolls. You and the defender make opposed attack rolls with your respective weapons. The wielder of a two-handed weapon on a sunder attempt gets a +4 bonus on this roll, and the wielder of a light weapon takes a -4 penalty. If the combatants are of different sizes, the larger combatant gets a bonus on the attack roll of +4 per difference in size category.
Step 3
Consequences. If you beat the defender, roll damage and deal it to the weapon or shield. See Table: Common Armor, Weapon, and Shield Hardness and Hit Points to determine how much damage you must deal to destroy the weapon or shield.
If you fail the sunder attempt, you don’t deal any damage.
Sundering a Carried or Worn Object
You don’t use an opposed attack roll to damage a carried or worn object. Instead, just make an attack roll against the object’s AC. A carried or worn object’s AC is equal to 10 + its size modifier + the Dexterity modifier of the carrying or wearing character. Attacking a carried or worn object provokes an attack of opportunity just as attacking a held object does. To attempt to snatch away an item worn by a defender rather than damage it, see Disarm. You can’t sunder armor worn by another character.
One who attempts to sunder a bastardsword with a dagger takes a -8 on his attack roll.
One who attempts to sunder a shield with a dagger takes a -4 on his attack roll.
I'm not sure if those penalties bring justice to your cause.
Moreover, considering hardness and HPs I'm sure its more difficult than it seems to pull this off with a dagger.
EDIT: Still, though, doesn't it seem strange to split apart a shield with a dagger or a knife, even with the -4 penalty?
The reason I asked the question was that, during last night's game, a PC used a dirk to sunder a wooden targe used by his enemy. The targe is Hardness 6 and Hitpoints 6. After the successful Sunder attempt, the PC rolled 12 points of damage. The dirk does 1d6 dmg, and the PC was under the Fighting Madness Feat, which boosted his STR bonus to +6. The player rolled a 6 on the die, bring the damage total to 12 points.
12 pts of damage - 6 Hardness = 6 points of damage to the shield. It's useless.
He did this with a big knife? Heck, a dagger, at 1d4 damage, would almost do it (leaving the shield 2 hp).
Really?
I'm trying to picture in my head what happens when a dirk, stilletto, knife, or dagger is used to sunder a shield...or even a sword.
We had another instance where the same PC tried sunder on a war sword and put a decent little nick in the blade.
That just seems strange, even with the -4 penalty on the sunder check, for light weapons. It seems too easy.
Ahh...just figured it out....you can't use a dagger, stilletto, or a dirk because they are piercing weapons.
The knife, though, it seems it can be used with the -4 penalty. It's a slashing weapon.
Think not of the blade, but of the muscle behind it.
Very good point. I tried to XP you, but it wouldn't let me.
"Steel isn't strong, boy. Flesh is stronger. Look around you... There, on the rocks, that beautiful girl...Come to me, my child....
That is strength, boy. That is power: the strength and power of flesh. What is steel compared to the hand that wields it? Look at the strength of your body, the desire in your heart. I give you this ...such a waste. Contemplate this on the tree of woe.
Crucify him."