You can choose to make a DC 14 Acrobatics check as an action when within melee range of an enemy. If successful, you perform an acrobatic action (a flip, cartwheel, parkour move, etc.) and can make an attack with a melee weapon as a bonus action, adding 1d6 to the damage roll (this increases to 1d10 at 6th level, 2d6 at 11th level, and 2d8 at 16th level). If you fail, you may not take any bonus actions this turn.