When you declare that you are dashing, track the total distance you cover. When you arrive at your destination, you may make 1 melee attack via Bonus Action. This extra attack deals an additional d4 bludgeoning damage for every 10 feet of ground you cover, to a maximum of 4d4 Add +1 to this total if you are wearing light armor, +2 if you are wearing medium armor, and +4 if you are wearing heavy armor. Add an additional +1 if you are carrying a shield. If you hit your target by 4 or more, the target is pushed up to 10 feet away from you, provided that your target is no more than 1 size class larger than you are and must make a Dexterity Save with a DC equal to your attack roll or be knocked prone.