The dagger is a fast and nimble weapon, and your mastery of it shows how elegance can be lethal. When you select this feat, you gain the following benefits :

At Level 3:
• You gain the ability to use a Dagger with your Off-hand and gain Modifier bonuses with it.
• Attacking at long range doesn’t impose disadvantage on your ranged weapon attack rolls made with daggers.

At Level 6:
You gain a +1 bonus to attack rolls you make with the weapon.
• Your critical hit range with daggers increases by one integer. (So, if you would normally score a critical hit on a 20, you now score a critical hit on a 19 or a 20. Likewise, if you would score a critical hit on a 19 or a 20, now you would score a critical hit on an 18,19, or a 20.)

At Level 9:
• When a creature misses you with a melee attack, you can use your reaction to make a melee weapon attack against the creature, with a dagger you are holding.

At Level 12:
• You gain a +1 to your AC while wielding 2 daggers at the same time

At Level 15:
• Your Dagger deal deals a d6 instead of a d4.

At Level 18:

• Your critical hit range with daggers increases by one integer. (So, if you would normally score a critical hit on a 20, you now score a critical hit on a 19 or a 20. Likewise, if you would score a critical hit on a 19 or a 20, now you would score a critical hit on an 18,19, or a 20.)