Shield Specialist

You've mastered the art of using a shield offensively as well as defensively. 

Shield Strike

At 3 level, as a bonus action, you can make an attack with the edge of your shield (buckler or standard) for d6+STR modifier bludgeoning (unless the shield is spiked or “edged” on the sides and bottom, then it is piercing) damage. Standard roll to hit to perform this attack and is a bonus action once per turn.

All-Guard Stance

At 7th level, you can use a bonus action to enter a defensive posture that grants an additional +1 to Armor Class while in this stance. YOU CAN USE THIS A NUMBER OF TIMES EQUAL TO YOUR PROFICIENCY BONUS PER LONG REST. Any action, reaction, bonus action or movement, will break the All-Guard Stance If none are made, the stance and bonuses remain in effect until your next turn. While in All-Guard Stance, you gain the following benefits:

1, Flanking benefits are negated. 

2, If a melee attack on you misses by your shield bonus, including the stance bonus, you can use your reaction to make a shield strike against the attacking creature. This will not break the All-Guard Stance. 

Flip

At 15 level, when using a standard or larger shield (excluding Tower Shields), you can hold your action until an opponent enters melee with you. Before he makes his attack, you step into his attack and make a contested STR Check to lift the attacker over your head and slam him to the ground on his back. You can then make a bonus weapon attack with advantage. If the contested STR Check is failed, you lose your attack for that round.

Enemy Exposed

At 15th level, you can use the shield to create an opening in your opponent’s guard and make an attack with advantage. This is a reaction allowed once per turn to an attack that misses you.

Combo

At 18th level, you can use a combination of any TWO of the previously learned Shield Specialist features as a single Action once per turn. For example, you can use 1 action to Bull Rush an opponent (part 1 of the Combo) and, instead of pushing back and prone, use the Enemy Exposed maneuver (part 2 of the Combo) to raise the opponent’s chin and make an attack with the bonus as explained in that maneuver. OR, you can set up for the Flip and when the opponent lands (part 1 of the Combo), perform a Shield Strike with the bottom of the shield as he lays prone (part 2 of the Combo).