When you hit a creature with a weapon attack, you can expend one superiority die to attempt to knock the target down. You add the superiority die to the attack's damage roll, and if the target is Large or smaller, it must make a Strength saving throw. On a failed save, you knock the target prone.
The DC is 13.
When you make a Charisma (Intimidation), a Charisma (Performance), or a Charisma (Persuasion) check, you can expend one superiority die and add the superiority die to the ability check.
On your turn, you can use a bonus action and expend one superiority die to bolster the resolve of one of your companions. When you do so, choose a friendly creature who can see or hear you. That creature gains temporary hit points equal to the superiority die roll (1d8) + your Charisma modifier (3).
The temporary hit points last until they are depleted, until the creature finishes a short rest or until you use this feature again.