Shield Master

You are mercenary, bounty hunter, soldier or former guard.

Whatever you are you know how to fight but you also know the most important thing is to protect yourself. You will never go outside without your armor and your shield.

Because if someone trying to hit you with crossbow armor is just not enough sometimes. Wielding 2 shields? What nonsense you are simple man but you know better.

Best defence is a good offence

Beginning when you choose this archetype at 3rd level, you can perform weapon melee attack with your shield as bonus action any shield attacks you do deal 1d4 + STR bludgeoning damage. Reference to this damage is written as shield die from now on. If your shield is magical add enchanted bonus (if any) to your attack and damage rolls you do with your shield and count as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Shield die of shields you find or buy is up to your DM consideration. 

At level 7 you are now skilled fighter and you know when and how to hit your opponent to deal more damage to them. If you will spend at least 50 gold for new better shield or if you already found better shield your shield die will change to 1d6 + STR.

And at level 10 if you will spend at least 200 gold for new high quality nice full metal shield  or if you already found better shield your shield die will change to 1d8 + STR.

(Shield is strong and heavy but it gives you only +2 AC)

Shield bash

In addition to that you can use action to strike your opponent with a great strength. If your attack hits your opponent they recieve damage from your shield die and have to make a CONSTITUTION saving throw of DC: 8 + prof. bonus + your STRENGTH modifier. If they fail they are stunned until end of their turn or until they succed a saving throw on start of their turn. If they succed they follow turn as normal. This feature do not affect undead and constructs or creatures that are significantly bigger then you (DM decide). 

Once you use Shield Bash on someone they will expect you to do it again so you can not use this feature twice at same creature in one fight.

You can use this feature number of times equal to your STRENGTH modifier (minimum of one use). And you regain all uses on short or long rest.

At level 7th if your opponent fails their saving throw they are stunned until start of your next turn instead. Immediately after you use Shield Bash feature you can perform one melee attack as bonus action.

At level 10th if your opponent fails their saving throw they are stunned until end of your next turn instead. Immediately after you use Shield Bash feature you can perform your attack action as bonus action.

Hold your shield in front of you

Starting at 7th level, if you move at least 15 feet in straight line immediately before using Shield Bash you can add double proficiency bonus for attack roll. And if you hit your Shield Bash DC also have double proficiency bonus.

You always can do this once per turn and once you use this trait, you can not use it again until you move 0 feet on one of your turns.

Shield is good for blocking

At 7th level, you learned how to defend yourself better against any ranged attacks.

If any ranged attack is aimed on you and if you are facing that enemy with your shield your cover will raise by one level (so if you have no cover you gain benefits of half cover and if you have half cover you gain benefits of three-quarters cover etc.), you can not earn this benefit if enemy is hidden from you or if they flank your cover.

 In addition to that you have advantage on Dexterity saving throws if you are facing caster with your shield that you can see or hear.

Take cover!

At 10th level, you are fast and combat ready not just for yourself but for your comrades in arms too.

You can use your shield in reaction of you or your ally no more then 5 feet from you being hit. Add your avarage shield die number to that target armor class. If your ally is still hit by that attack they receive only half of that damage and you receive the other half. But you are resistant to all damage from this attack.

In addition to that if you have Protection fighting style this feature take effect at the same time if you are protecting an ally.

If you or your ally no more then 5 feet from you being hit by critical strike. You may use your reaction to Shield Bash this enemy (if enemy is in your reach). If you hit and if your enemy fail their saving throw they are stunned and that critical strike is canceled. Any effects triggered by a critical hit are also canceled.

Taunting deffence

Starting at 15th level, if you use dodge action on your turn you can make one melee weapon attack as part of that action.

In addition to that you taunt your enemies around you by yealling and rattling noises as your weapon hits your shield. Any enemies around 40 ft. circle in diameter with you in center that can hear or see you have to succeed WISDOM saving throw DC 8 + prof. + CHAR if they fail they will be focused on you and any attacks they do to your allies have disadvantage.

You can use this feature number of times equal to your CHARISMA modifier (minimum of once). You regain all uses at long rest.

Your DM might consider to make your area bigger or smaller depending on your surroundings.

Glorious Charge

At 18th level , you are fast and strong. You may now use your reaction to take your turn on end of ally your turn instead of your normal initiative count.

You follow your turn as normal but your speed is doubled and if you move in straight line you may move through medium or smaller enemy creatures as if you move through difficult terrain. Shoving them prone on pile 5ft. in front of you at place where you turn or stopped. These creatures can't use attack of opportunity on you and they are also damaged by your shield die.

In addition to that you have advantige on all enemies hit by your Glorious Charge.

You can't use this feature again until you finish a long rest.