The unseen attack

Your weapon attacks score a critical hit on a roll of 19 or 20 with daggers.

You add +10 to Sleight of Hand (Dexterity) checks to conceal a dagger.

Throwing a dagger at long range does not cause you to roll with disadvantage.

When you roll a 1 on a damage die with a dagger, you can reroll the die and must use the new roll, even if the new roll is a 1.