Duelist

Features

Prowess

When you choose this archetype at 3rd level, you learn techniques that are fueled by a special reserve of strength called prowess.
  Techniques. You learn three techniques of your choice from those described below (see “Techniques”). You can use only one technique per attack. You learn one additional technique of your choice at 9th, 13th, and 17th levels. Each time you learn a new technique, you can also replace one technique you know with a different one.
  Prowess. You have an amount of prowess equal to your proficiency bonus × 2. To spend prowess, you must be wielding a finesse weapon in one hand and have either nothing or a dagger in your other hand. You can spend prowess once per turn. You regain all spent prowess when you finish a short or long rest.
  Saving Throws. Some of your techniques require your target to make a saving throw to resist an effect. The saving throw DC = 8 + your proficiency bonus + your Dexterity modifier.
 

Dancing Blade Needs adjustment

Also at 3rd level, you can wield a rapier as a light weapon, provided you have nothing heavier than a light weapon in your other hand.  

Strike First, Strike Last

Starting at 9th level, your reflexes are honed to a razor’s edge, granting you advantage on initiative checks. Additionally, if you are surprised, you can take the Attack action on your first turn by spending 1 prowess.  

Virtuoso

At 13th level, choose two skills from the following list: Acrobatics, Athletics, Deception, History, Intimidation, Persuasion, Sleight of Hand. You gain proficiency in the chosen skills, or add double your proficiency bonus if you are already proficient.  

Deep Reserve

Starting at 17th level, when you roll initiative and have no prowess remaining, you regain 2 prowess.  

Techniques

The techniques are presented in alphabetical order.
  Clinch. Immediately after you hit with a finesse weapon, you can spend 2 prowess to automatically grapple the creature you hit. Normal size and reach restrictions apply. Select one of the creature's attack actions; for as long as the grapple persists, the creature has disadvantage with that attack. You can maintain this grapple even if you hold a dagger in your offhand.
    Deep Slice. When you inflict damage with a finesse weapon, you can spend 1 prowess to deal a deep, bleeding wound. At the start of its turn, the bleeding creature must make a successful Constitution saving throw or take 3 (1d6) piercing damage. On a successful save, the effect ends. The creature or its adjacent ally can end the effect by spending an action to use a healer’s kit or to make a successful Wisdom (Medicine) check against your technique save DC. Any amount of healing also ends the effect. A deep slice has no effect against constructs and undead.
  Disarming Parry. When you are missed by a melee attack, you can spend 1 prowess as a reaction to force the attacker to make a Strength saving throw. If it fails, the attacker drops the weapon it attacked with. If you have a free hand, you can catch the weapon with a successful DC 10 Dexterity check; otherwise it lands 10 feet away from the attacker in a random direction.
  Driving Assault. When you take the Attack action, you can spend 2 prowess to press your target back. Until the end of your turn, each time you hit with a finesse weapon, the target must succeed on a Dexterity saving throw or move 5 feet away from you. The target can be no more than one size category larger than you. You can immediately advance into the space the target vacated if you wish, without triggering an opportunity attack.
  Effortless Steps. When you take the Dash action, you can spend 1 prowess to ignore nonmagical difficult terrain, and climbing doesn’t cost extra movement until the end of your turn. You can spend 1 additional prowess to move through a single foe’s space without triggering an opportunity attack from that creature.
  Pommel Punch. When you make an attack, you can spend 2 prowess to strike the target with the pommel of your weapon instead of the blade. This does 1d6 bludgeoning damage instead of the weapon's normal damage dice, and the target must make a successful Constitution saving throw or be incapacitated until the end of its next turn. The target can be no more than one size category larger than you.
  Rapid Strikes. If you make a second attack with a light weapon in your off-hand, you can spend 1 prowess to add your ability bonus to this attack's damage roll.
  Stick and Move. After you attack with a finesse weapon, you can spend 2 prowess as a bonus action to move half your speed. This movement doesn’t provoke opportunity attacks.
  Tagging Strike. When you hit a creature with a finesse weapon, you can spend 2 prowess to impair your target by cutting a strap, injuring a joint, or dealing some other distracting blow. The target must make a successful Constitution saving throw or have disadvantage on the first attack roll or ability check it makes during its turn. The effect ends when the creature makes the saving throw successfully or spends an action to end it (readjusting its gear, regaining its balance, etc.)
  Wall of Flashing Steel. As a reaction when you are hit by a melee weapon attack, you can spend 2 prowess to attack with a finesse weapon. If the result of your attack roll exceeds your AC, use the attack roll in place of your AC until the start of your next turn. This can cause the triggering attack to miss.
  Witty Repartee. As a reaction after a creature you can see makes an attack roll, ability check, or saving throw but before success or failure is revealed, you can spend 2 prowess to encourage or mock the creature. If the creature can hear you, roll a d4; the result is added to or subtracted from the creature's attack roll (your choice).