This dagger is designed for parrying blows, and if your timing is perfect, catching an opponent's blade and potentially disarming them. The dagger's attacks do not count as magical. When a creature targets you with a melee weapon attack, you can use your reaction to attempt to parry their attack. You can make a parry attempt a number of times equal to your proficiency bonus, recharging after each long rest. When you make this attempt, make a dexterity check. Your AC for this specific attack increases by the result of the check, divided by six, rounded down (So, if the total result of your roll is a "20," your AC is momentarily increased by 3). If the attack misses, the creature attacking you makes a dexterity check. If their check is lower than yours, you get a free opportunity attack with a weapon in your other hand. If their check is more than 10 lower than yours, the creature drops their weapon and is disarmed - and you get your opportunity attack.

An example: A monster attacks with their broadsword, and you attempt to parry. You roll a dirty 19, and so your functional AC increases by 3, to 18. They roll a 17 to hit, so they miss. They roll a dexterity check and get an 18. Their sword is caught by your parrying dagger for a moment, and you use the opportunity to stab them with your rapier.

 

This dagger is not designed for throwing, and if used as a ranged weapon, the ranged attack has disadvantage.

Proficiency with a Dagger allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Damage, Control, Combat, Finesse, Light, Thrown, Nick