Legionnaire

You have always worn a shield and it has become apart of you just as much as those around you.  You protect them and they protect you as you form an immovable line.  

Shield Slam

Beginning when you choose this archetype at 3rd level, you may spend your bonus action after you have taken the attack action to make a shield slam attack against a creature within 5 feet of you.  You must have a shield equipped to use this ability.  The creature must make a strength saving throw vs your Strength DC.  On a fail, they are considered staggered, roll a 1d6 to determine what effect stagger has on them. The stagger effect ends at the end of the creatures next turn. You may use these a number of times equal to your Strength Modifier (Min 1).  You regain all uses on a Long Rest.

Stagger Effects

1.  Creature has Disadvantage on the next weapon attack
2. Creature is pushed back 10 feet
3. Creature takes 1d4 + Strength Modifier bludgeoning damage, this increases to 2d4 at level 12
4. Creature can not take reactions
5. Creature movement speed is halved
6. Creature is knocked prone

Immovable

Starting at 7th level, so long as you have a shield equipped you can use your reaction to prevent yourself from being pushed, pulled or knocked prone. You may use this ability once per short rest

Live and Let Live

Starting at 10th level, you have earned the respect of others by protecting them and standing in the front line.  Whenever you attempt to find lodging and food for the night, the cost is reduced by half.  Additionally, you always know where the to find the best vice the town has to offer and the best establishment for it, be it gambling, drugs, drinking, etc.

Stand Together

Starting at 15th level, whenever you are adjacent to a non hostile creature that is equipped with a shield. You grant that creature an AC bonus equal to your shield bonus to AC. Example: if you are currently using a Shield +1, this will grant the creature +3 bonus to their AC. Conversely that creature also grants you a bonus to your AC based on their shield bonus to AC modifier.

My life for others

At 18th level, when a creature that is non hostile to you and within 5 feet is attacked you can spend you second wind ability to reduce that damage to them. If the damage is reduced to zero, you may spend your reaction to make a shield slam attack against the attacking creature.  This attack uses one of your uses of your shield slam ability.