
cranewings |
Can I use a dagger two handed?
In real life I know I can. Nothing would stop me from gripping my wrist with my free hand and driving it harder.
Sure, there are reasons knife fencers don't usually do it that way, least of which that hp isn't real and a tiny cut can lead to fatigue and death while the killer dances around.
But still, it would be a terrible wound, two hand drive that is.

gran rey de los mono |
Can I use a dagger two handed?
In real life I know I can. Nothing would stop me from gripping my wrist with my free hand and driving it harder.
Sure, there are reasons knife fencers don't usually do it that way, least of which that hp isn't real and a tiny cut can lead to fatigue and death while the killer dances around.
But still, it would be a terrible wound, two hand drive that is.
Yes, you can use a dagger two handed. But since it is a light weapon you gain no benefit from doing so.

concerro |

Nope. Well actually yes, but it gives no advantage.
PRD:Light: A light weapon is used in one hand. It is easier to use in one's off hand than a one-handed weapon is, and can be used while grappling (see Combat). Add the wielder's Strength modifier to damage rolls for melee attacks with a light weapon if it's used in the primary hand, or half the wielder's Strength bonus if it's used in the off hand. Using two hands to wield a light weapon gives no advantage on damage; the Strength bonus applies as though the weapon were held in the wielder's primary hand only.

Ksorkrax |

Three issues about realistical fighting with daggers in this context:
1. Daggers are weapons of concealment or secondary weapons (should you loose your sword during a fight) or even weapons you wear if you're not actually expecting a fight (like when you're going to harvest your crops or on the way to the theatre) - in fantasy scenarios we got these assassin styled guys who fight with two daggers or something like that, well that's the fantasy part.
2. Actual fighting is about defensive stances. For example, the medieval battle schools for two handed swords revolve around some very effective stances that allow you to block any incoming strike while giving you a good attacking position. It's the same with daggers, but daggers have a low reach which is quite bad for a good stance. To enhance your reach, you lengthen your arm (watch a video about a knife fight - that's two guys dancing around each other, feinting until they think they can land a blow unopposed). Now try that with both hands on the dagger - you loose distance and the left arm to counterbalance your steps, so even if your hilt was long enough for two hands you won't hold it this way
3. Two hands cause troubles when stabbing your enemy which you want to do. Daggers are damn pointy, they don't need the strength of another arm plus the reach limits your target points for stabbing.
On the other hand, as for the game mechanics it's certainly no game breaker to enhance a weak weapon like the dagger.

The Shaman |

On the other hand, as for the game mechanics it's certainly no game breaker to enhance a weak weapon like the dagger.
Eh, simple weapon light that can alternate between piercing and slashing damage, can be thrown, easy to conceal, available pretty much anywhere, few legal issues in most fantasy societies, can be used for utility purposes as well... How much more do you want? I guess you could have a martial version giving bonuses to disarm or some such, but I doubt it would have all the features.

cranewings |
Personally, I'd say that two-handing a dagger is more for when you're going for a coup-de-grace (or maybe for power attack?). Otherwise you'll have characters that swing daggers 2-handed as their standard method of combat, and that's what would be really dumb.
I could get behind that, at least for a game where making up rules isn't my job ;)
I do like the people that say they know about martial arts and ancient war. I did martial arts as well and I think everything is situational. In kali and silat, I can think of about half a dozen reasons to take a knife in two hands off the top of my head. Bashing a face with the bottom or unzipping someones torso after disabling them are just two.
I guess I'd like a rule that allowed finese weapons to be used as two handed power attacking weapons, perhaps with a stiff penalty to strike and AC.
Pause
There, I just practiced holding something in two hands and stabbing down. I also practiced swing while pushing the bicep with my off hand. Both motions were at least 50% stronger than normal.

cranewings |
2. Actual fighting is about defensive stances. For example, the medieval battle schools for two handed swords revolve around some very effective stances that allow you to block any incoming strike while giving you a good attacking position. It's the same with daggers, but daggers have a low reach which is quite bad for a good stance. To enhance your reach, you lengthen your arm (watch a video about a knife fight - that's two guys dancing around each other, feinting until they think they can land a blow unopposed). Now try that with both hands on the dagger - you loose distance and the left arm to counterbalance your steps, so even if your hilt was long enough for two hands you won't hold it this way.
Your assumptions about knife fighting aren't universal. The two guys dancing around is just fencing where neither fighter has a motivation to leave, nor a motivation to finish the fight early, do not represent the many ways it can go.
Another way to knife fight is in a hurry, where you blitz the other person, try to disarm or stun them, and then, successful or not, try to deliver the most savage knife wound possible knowing that the only way to live and win is to survive the trip to the hospital better. Lots of people believe that a fancying dancing fencer can't handle a blitz. Because most people learn in groups where everyone does the same thing, they are usually right. The fancy dancer will ineffectively cut back in a panic while the super stabbed touches his spine via his belly.
All fighting is situational, subject to personality and motivation. Just because all the little Dan Inasanto copy cats mostly bait for wrist cuts doesn't mean that is the best or only way to knife fight, especially in a setting where everyone has armor on.