Improviser

While most assassins, thieves and overall scoundrels of the shadows choose to restrict themselves by using particular weaponry and remaining unseen, there are those who can more easily express their skillset in combat. Whether it is a spoon, fitchfork, rooftile or any other mundain object, for some, anything can be a weapon. And thus, these masters of improvised fighting don't find themselves always prepared for battle, and yet they stil find themselves to escape with their lives, thanks to some quick thinking, adaptability and creative use of the objects and space around them. A man with a sword is considered dangerous, but that begs the question, which of the two is dangerous? The sword, or the man?

Off The Cuff

Starting at level 3, you gain proficiency with improvised weapons. They deal 1d4 piercing, bludgeoning or slashing damage, of the DM's choosing, and they have the finesse property for you. Often, an Improvised Weapon is similar to an actual weapon and can be treated as such, and so improvised weapons that resemble certain weapons could have the same properties. For example, a jagged stone could have the same properties as a dart.

Improvised Fighting

When you choose this archetype at 3rd level, you gain new ways to use your Cunning Action.

As a bonus action you can take the Grapple, Search or Shove actions.

Improvised Fighting Style

Starting at 9th level, you can choose one of the following Fighting Styles from the Fighter class every time you roll initiative. The Fighting Style stays till the next time you roll iniative, after which you can choose to change your Fighting Style.

Archery

You gain a +2 bonus to hit with ranged weapon attacks.

Blind Fighting

You have blindsight with a range of 10 ft. Within that range, you can effectively see anything that isn’t behind total cover, even if you’re blinded or in darkness. Moreover, you can see an invisible creature within that range, unless the creature successfully hides from you.

Defense

While you are wearing armor, you gain a +1 bonus to AC.

Dueling

You gain a +2 bonus to damage when wielding only a weapon in one hand.

Great Weapon Fighting

You can reroll a 1 or 2 on damage dice with melee weapons wielded with two hands.

Interception

When a creature you can see hits a target, other than you, within 5 ft. of you with an attack, you can use your reaction to reduce the damage the target takes by 1d10. You must be wielding a shield or a simple or martial weapon to use this reaction.

Protection

While wielding a shield and a creature you can see attacks a target other than you within 5 ft., you can use your reaction to impose disadvantage on the attack roll.

Superior Technique

You learn one maneuver of your choice from among those available to the Battle Master archetype. If a maneuver you use requires your target to make a saving throw to resist the maneuver’s effects, the saving throw DC equals 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice).
You gain one superiority die, which is a d6 (this die is added to any superiority dice you have from another source). This die is used to fuel your maneuvers. A superiority die is expended when you use it. You regain your expended superiority dice when you finish a short or long rest.

Thrown Weapon Fighting

You can draw a weapon that has the thrown property as part of the attack you make with the weapon.
In addition, when you hit with a ranged attack using a thrown weapon, you gain a +2 bonus to the damage roll.

Two-Weapon Fighting

You add your ability modifier to damage for off-hand attacks.

Unarmed Fighting

Your unarmed strikes can deal bludgeoning damage equal to 1d6 on a hit. If you aren’t wielding any weapons or a shield when you make the attack roll, the becomes a d8.
At the start of each of your turns, you can deal bludgeoning damage to one creature grappled by you.

Improved Improvisation

By 13th level, you have learned to make your improvised weapons more deadly. Your improvised weapons do 1d6 damage and are considered magical.

Additionally, when you roll a skill check with which you are not proficient in, you gain a +2 on that skill check.

Quick Adaptater

When you reach 17th level, on the first turn of combat, you may take your turn before anyone else. If you hit an enemy with an improvised weapon during this turn, you automatically get Sneak Attack and that hit gets 3d6 additional damage.