Reactive Knockdown
(1
point)
2nd degree
Adamant Mountain
Reaction
Putting yourself in just the right position as you strike, your unbalancing hit sends a retreating opponent into a reeling stumble and then the ground.
When a creature within your reach provokes an opportunity attack, you can use your reaction to make a melee weapon attack. On a hit, the creature makes a Strength saving throw or it moves 10 feet in a straight line and is knocked prone .
Source