"The Broad Dagger is a very simple weapon, primarily designed to slash and cut the flesh of an enemy. It’s broad base allows it to be very well balanced, resulting in it being one of the quickest weapons to strike in the game."
This is the Man-at-Arm's and Archer's "standard" sidearm that features a hard learning curve with good payoff. Like other daggers, it's overhead attacks differ whether a shield is equipped or not. With a shield, it features two swing-damage Horizontal/Overhead strikes, and a piercing stab. The stab is arguably the most important of the weapon's attacks, since it overcomes the harsh swing resistance of Knights and Vanguards to the Broad Dagger's already low damage. Therefore, it is advantageous to equip this weapon without a shield, which transforms your overhead slashes into reverse-grip stabs.
For a faster stab, the Thrusting Dagger may be preferred. However, the Broad Dagger's slashes are more reliable in team fights.
Out of all the daggers in the game, the Broad Dagger is the longest with a noteworthy lead. This causes some debate to the performance of Broad Dagger's stab relative to the faster but shorter Thrusting Dagger's.