Vine Strangle

Send a vine through the ground at your opponent, raising it up out of the ground and choking them. Roll a d20. If the roll is below 10, roll a d8, they are knocked unconscious and receive that many hit points in damage. If the roll is above 9, then roll a d20, your opponent in knocked unconscious and receive that many hit points in damage. If you roll above a 9 and their AC is less that 16, they are immediately are down to one hit point. And if you roll a perfect twenty, you choke them to death and they are immediately killed.