Tactician (5e Feat)

Your experience and study in combat tactics lets you shout out guiding words to aid your allies. You gain the following benefits:

You learn two of the following maneuvers from those available to the Battlemaster Archetype of the fighter class: Commander's Strike, Distracting Strike, Maneuvering Attack, and Rally. If a maneuver you use requires your target to make a saving throw to resist the maneuver’s effects, the saving throw DC equals 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice).
If you already have superiority dice, you gain two more; otherwise, you have two superiority die, which are d6s. These dice are used to fuel your maneuvers. A superiority die is expended when you use it. You regain your expended superiority dice when you finish a short or long rest.
You can give tactical advice to give your allies an edge in combat. When an creature other than yourself within 60 feet of you who can hear you makes an ability check, attack roll, or saving throw, you can use your reaction and expend one superiority die. The creature adds the the number you roll on your superiority die to their roll. You can wait until after it rolls the d20 before deciding to use the superiority die, but must decide before the DM says whether the roll succeeds or fails.