Shieldbreaker

The Shieldbreaker dashes past a sturdy frontline to strike the man giving orders.  Whether trained this way by one's beloved comrades or inspired to take up this mantle by cruel masters overcome on a harsh desert path, fighters who emulate the Shieldbreaker archetype are focused masters of bypassing the enemy company's guard and engaging the foes who truly matter.  For the Shieldbreaker, mobility is a tool of both offense and defense.  The Shieldbreaker is a mobile tactician-- the tip of the spear.

Dance of Battle

When you choose this archetype at 3rd level, your walking speed increases by 5 feet while you are not wearing heavy armor.  Regardless of your choice of armor, you can move through the spaces of hostile creatures, and you have a bonus to AC against attacks of opportunity equal to your proficiency bonus +2.

Starting at 10th level, the bonus to speed granted by this feature increases to 10 feet, and the moving through other creatures' spaces doesn't count as difficult terrain for you.

Serpent Sway

 Starting at 3rd level, you have advantage on ability checks and saving throws made to avoid being grappled or restrained, and you can attempt to escape from grapples as a bonus action.

Spear Mastery

Starting at 3rd level, you can use Dexterity instead of Strength for the attack and damage rolls of weapon attacks you make using spears.  Melee weapon attacks you make using spears ignore half and three-quarters cover, and ignore resistance to piercing damage.

Additionally, when you make a melee weapon attack on your turn with a spear, you can add 5 feet to your reach for the attack.  You do not gain this benefit if some other feature or trait also increases your reach for the attack.

Debilitating Strike

Starting at 7th level, you are skilled at targeting your opponents' weak points to hinder their movements or break their defenses.  Once per turn when you hit a creature you can see with a weapon attack, the target takes an additional 1d6 damage, and you can inflict one of the following effects:

• The target's speed is reduced by 10 feet until the end of your next turn, or 15 feet if the target has less than half its maximum hit points remaining.
• The target must make a Constitution saving throw.  On a failure, attack rolls made against the target have advantage until the start of your next turn.
• The target must make a Constitution saving throw.  On a failure, it can't take reactions until the end of your next turn.

Effects that require a saving throw have a DC equal to 8 + your proficiency bonus + your Strength or Dexterity modifier.  Creatures with less than half of their maximum hit points remaining have disadvantage on the save.

Aegis Defense

Starting at 10th level, you are able to avoid even the most powerful attacks when you focus your attention fully on defense.  When you use your second wind or take the dodge action, until the end of your next turn, as a reaction you can reduce to 0 the damage you take from an attack or an effect that you made a Dexterity saving throw against.  You can take this reaction twice, and regain all expended uses when you finish a short or long rest.

Improved Debilitating Strike

Starting at 15th level, you can use your Debilitating Strike feature twice on your turn.

Dancer's Fangs

At 18th level, with feints and spacing your masterful footwork enhances both your offensive and defensive capabilities.  When you move at least 10 feet on your turn, you have a +1 bonus to attack rolls you make with melee weapons on the current turn, and a +1 bonus to AC and Dexterity saving throws until the end of your next turn.