Opportunist (5e Subclass)
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You have learned to exploit the weakness of your enemies at any opportunity you have.
You Can't Surprise Me
At 3rd level, you can make opportunity attacks even when you are surprised.
At 3rd level, when you successfully hit an enemy with a melee attack, you can attempt to push your opponent back. They make a Strength saving throw. On a failed save, they are pushed 5 feet straight back.
This increases to 10 feet at level 10.
The save is equal to 8 + your Strength modifier + your proficiency bonus.
Sweep the Feet
At 7th level, when you successfully hit with a melee attack, you can do a leg sweep on the enemies. They must roll a Dexterity saving throw. On a failed save, they are knocked prone.
The save is equal to 8 + your Dexterity modifier + your proficiency bonus.
At 10th level, when an opponent misses you with a melee attack, you can use your reaction to make a melee attack against them.
At 15th level, your extra attack now applies to opportunity attacks you make
At 18th level, you can make a critical hit when you do an attack of opportunity on an 18, 19 or a 20 and when you roll a critical hit, you deal an extra 1d12 damage (2d12 if you use a two-handed weapon)