Fighter Subclass

The Duelist is a fighter who seeks the mastery over the art of fencing. They are masters on the use of swords and daggers, relying on quick footwork and swift wrist moves to simultaneously attack and parry. To the duelist, armors and shields are detrimental to their style, that relies on agility and cunning to defend themselves in a fight. More than warriors, duelists are scholars, often writing treatises on the use of the sword, so the swordplay for them is both a physical and a mental skill. Duelists are often proud, fighting to protect their honor or just to prove a point. A fight between Duelists is most of the times more than mere combat, but an argument, where the debaters exchange blade strokes instead of words.

This is inspired by the 3.5 Duelist prestige class, from "swords and fists".

Bonus Proficiencies
When you choose this archetype at 3rd level, you gain proficiency in one of the following skills of your choice: Acrobatics, Athletics, History, or Deception. Alternatively, you learn one language of your choice.

Canny Defense
At 3rd level, your practicing of fencing gives you mastery over the use of finesse weapons. While wielding a finesse weapon and not wearing armor or using a shield, your AC is equal to 10 + Intelligence modifier + Dexterity modifier. In addition, you can add your Intelligence modifier to your initiative and to your Strength (Athletics) skill checks.

Precise Swordplay
At 3rd level, you begin to develop a particular fighting style, based on lunging with your thrusts and parrying with your weapon. You gain access a special bonus die called precision die, which is a d4. While wielding a finesse weapon, you can use your bonus action to assume one of the following styles bellow.

Precise Strike.You can add your precision die to the damage of your successful attacks with a finesse weapon.

Parrying Blade.You can reduce the damage of any weapon attack you receive by your precision die + your proficiency bonus.

Balanced Fighting.You gain a pool of precision dices equal to your Dexterity modifier. You can chose between adding the precision die to the damage of your attack, or to reduce the damage of an weapon attack.
The size of the die increases at 5th level (d6), 16th level (d8), and 20th level (d10).

Feline Grace
At 7th level, your careful study of your movements make your steps swift and elegant.You can add your Intelligence modifier as a bonus to your Dexterity (Acrobatics) skill checks.

In addition, you gain proficiency in Dexterity saving throws. If you already have this proficiency, you instead gain proficiency in Intelligence or Charisma saving throws (your choice).

Acrobatic Charge
At 10th level, you can make the environment work at your favor, dancing and cutting through even the most harsh floors. When you take the dash action, you can use your bonus action to make a melee weapon attack or to shove. In addition, when taking the dash action, your movement speed is not reduced by difficult terrain.

Enhanced Mobility
At 15th level, you can move in and out your opponent range with speed, becoming annoyingly hard to hit. You can use your reaction to impose disadvantage when you are targeted by an opportunity attack. In addition, when you take the dodge action, you can add another dice of disadvantage to the attacker.

Elaborate Parry
At 18th level, you learn how to parry and attack in one movement. You can use your precise swordplay die to reduce damage even if you has already used this die to add damage to a weapon attack on your turn.