Gladiator

Even in the most civilized societies, fighters and warriors can find themselves in battle arenas against horrifying creatures or other gladiatorial challengers. These fighters who live on the excitement of these pits and arenas proudly call themselves gladiators, warriors who can survive even the toughest and most challenging opponents. Gladiators use an opponent's momentum against them, retaliating against incoming attacks and shrugging off minor cuts and wounds, fighting past the point where most others would fall to exhaustion.

Counter Attack

At 3rd level, your defensive posture fuels your ability to counter an enemy's blows.  When you take the Dodge action, until the start of your next turn, when a creature misses you with an attack you can use your reaction to take the Attack action against that creature.

Showman

Performance is as much part of your training as the use of your weapons. When choosing this archetype at 3rd level you gain proficiency in Performance. 

Quintessential Performer

At 7th level, your performance is explicitly tied to your combat prowess. When making a Performance ability check, you can use your Strength or Dexterity (your choice) ability instead of Charisma if using weapons or physical displays. Creatures who are impressed by your display temporarily have a more friendly disposition towards you.

Experienced Brawler

At 10th level, when you use Second Wind, you also gain temporary hit points equal to the amount restored.

Preemptive Counter

At 15th level, when you take the Dodge action on your turn, you can immediately make one weapon attack against a creature that you can see.

Arena Veteran

At 18th level, you have learned to shrug off the weakest of attacks. When the damage from one attack or spell would be equal to or less than your fighter level, you are resistant to that damage. If the damage is less than half of your fighter level, you are instead immune to that damage.