Duelist (Melee)

“The sword was perfected long ago; the challenge now is to master it.”
-Master Duleo, Grace in Combat

The Duelist is a combat specialist that has spent many years of their life perfecting the art of swordplay. Focusing their training on finesse, the duelist can effortlessly perform complex feats of weapon prowess in the heat of battle.

Rules of Dueling
There are not always rules in a duel. If, for example, dueling is prohibited by law it may very well be the case that only a few rules survive. These surviving rules may be no than courtesies based on the traditions of the past. So before you slap someone across the face with your finest glove, you may want to consult your DM about how dueling is handled in their world.
What follows are two lists designed to inspire or provide DMs with a starting point for conducting duels.

Rules from the Codex of Duelo
1. Demand satisfaction; issue a challenge to duel.
2. The principal parties are to acquire secondary parties to enter negotiations for peace on their behalf.
3. If no agreement to peace can be made, the seconds are to find an equitable time and area of ground for the duel to take place.
4. The time and place of a duel shall be as convenient as possible to surgical assistance as well as to the combatants. No duel shall be fought on a day of festival or near a place of worship.
5. The challenging party determines which conclusion is acceptable: first to bleed¹, first to fall², first to die.
6. The principals are to each have written and signed documentation regarding the cause of the duel and the agreed upon terms of the duel.
7. In combat, the principals are permitted no more than three exchanges. After each exchange the seconds are to mutually and zealously attempt a reconciliation.
8. No injured creature should be abandoned on the field of honor without first securing them proper medical attention.
9. The matter concluded, the principals of a duel are to abstain from conversation upon the offending subject.
¹First to take damage.
²First to surrender the fight or fall unconscious.

Common Dueling Etiquette
  The choice of weapon, if any, is entitled to the challenged party.
  The principals are to salute each other upon meeting - as a sign of civility.
  Any unexpected advantage is entitled to the challenged party.
  Seconds present the weapon to the principal in presence and full observation of each other.

Fencing Skill

At 3rd level, you’ve learned all the techniques necessary to effectively defend yourself in a duel. While you are wielding a melee weapon with the finesse property you may take the Dodge action as a bonus action on your turn.

Subtle Wrist

You’ve learned how to maneuver your weapon to avoid your opponent's defenses. When you make an attack using a melee weapon with the finesse property you may add 1d6 to that roll. You must use this feature before the results of the attack roll are known.

You can use this feature a number of times equal to your Wisdom modifier, and you regain all expended uses of it when you finish a short or long rest.

Single Combat Proficiency

You also gain an additional way to use your Sneak Attack; you don’t need advantage on the attack roll to use your Sneak Attack against a creature if you are within 5 feet of it, no other creatures are within 5 feet of that creature, no other creatures are within 5 feet of you, and you don’t have disadvantage on the attack roll. All the other rules for Sneak Attack still apply to you.

Premeditation

At 9th level, your experiences have given you the ability to act nearly as fast as you can think. You gain a bonus to your Initiative rolls equal to your Wisdom modifier. Additionally, you gain advantage on melee weapon attack rolls against any creature that hasn’t taken a turn in the combat yet.

Counter

At 13th level, you’ve learned how to counter-attack an opponent as they prepare to strike you. While you are wielding a melee weapon with the finesse property, other creatures may provoke an opportunity attack from you when they enter the reach you have with that weapon.

Finishing Touch

At 17th level, your attacks are always well placed. Whenever you hit with a melee weapon attack, the target suffers additional damage equal to half of the damage from that attack.