Scrapper

While most Fighters hone their skills through military training, some instead master the martial arts in a much less strict and well-equipped environment. Scrappers are born in the often haphazard and unpredictable world of bar fights, underground fight clubs, and dangerous slums. Where resources and equipment are scarce, those that can best make use of their body and environment alone as weapons rise to the top as legendary scrappers. 

Scrapper's Way

At 3rd level, you embrace combat styles that use unarmed strikes, improvised weapons, and light weapons. You gain the following benefits while you are unarmed, wielding light weapons, or wielding improvised weapons, and not wearing medium armor, heavy armor, or a shield:

• You can use Dexterity instead of Strength for the attack and damage rolls of your unarmed strikes and improvised weapons.
• You can roll a d4 in place of the normal damage of your unarmed strike or light or improvised weapon. This die increases as you gain fighter levels, becoming a d6 at 7th level, a d8 at 10th level, and a d10 at 18th level.
• When you use the Attack action with an unarmed strike or an improvised or light weapon on your turn, you can make one unarmed strike, grapple, or shove as a bonus action. For example, if you take the Attack action and attack with a dagger, you can also make an unarmed strike, grapple, or shove as a bonus action, assuming you haven’t already taken a bonus action this turn.
• You can use your Constitution modifier in place of your Dexterity bonus to AC (requires manual override in D&D Beyond).
• You can make a Dexterity (Acrobatics or Sleight of Hand) check in place of the normal Strength (Athletics) check to attempt a shove. You can only knock a target prone this way.

Back it Up

At 7th level, you can effortlessly stop anyone that tries to escape your reach. When you use your reaction to make an attack of opportunity, you can replace the attack with a grapple attempt.

You also gain proficiency in Dexterity saving throws.

Your unarmed strike damage die becomes a d6.

Get Down

At 10th level, you can make a running tackle to topple opponents in combat. As an action, you can move up to your speed (must move at least 10 ft.) toward a target and make a shove attempt to knock the target prone. If your shove attempt succeeds and you have at least one free hand, the target is also grappled. If your hands are full, the target is simply prone.

Additionally, your unarmed strikes count as magical for the purpose of overcoming resistance.

Your unarmed strike damage die becomes a d8.

Drop it

At 15th level, you are able to wrest the weapon from an opponent's grasp. As an action, you can attempt to disarm an opponent. Roll a Strength (Athletics) or Dexterity (Sleight of Hand) check conested by the opponent's Strength (Athletics) or Dexterity (Acrobatics) check. On a successful check, the target drops one item of your choice it is holding. If you have a free hand you can immediately hold the item, no action required.

Break it Down

At 18th level you learn to harm your opponents at every opportunity. When an opponent starts its turn grappled by you, or you successfully shove an opponent, it takes damage equal to 1d8 plus your Strength modifier. This damage can only apply on your turn.

Additionally, when an opponent in melee range misses you with an attack, you can use your reaction to attempt a grapple or shove against them. 

You unarmed strike damage die becomes a d10.