I worked to polish the concept originally posted by [MENTION=6871653]vincegetorix[/MENTION] into a formalized archetype.
Enforcer
Some rogues are good at stealing, others for infiltration or killing. But you are the guy a boss calls in to do the dirty work. Breaking knees, scaring marks into paying on their “protection” fees, and kidnapping folks are all in a day’s work. You don’t rely on finesse or subtlety. Your tools of the trade are blunt, obvious, and effective.
Thug
You have learned to use the tools of your trade with even greater effect. Starting at 3rd level, you can apply your sneak attack damage while using a melee weapon that deals bludgeoning damage, even if it isn’t a finesse weapon.
Brute
When you fight, you fight dirty. Beginning at 3rd level, you can make the Shove action as a bonus action.
Nasty Backswing
Although sometimes you may miss, you usually still graze your opponent to make sure they know how lucky they are to have avoided the blow. Whenever you miss with an attack, if a hit would have allowed you to add sneak attack damage, the target takes weapon damage equal to the number of sneak attack dice in your pool.
Mug
By 13th level, you have become an expert in putting the fear of god into your victims. As an action you can choose a target within 60 feet. That target must make a Wisdom Saving Throw (DC 8 + Proficiency Bonus + Your Strength Modifier). If the target fails they become frightened. A target frightened in this matter automatically fails any perception or investigation checks to remember your features or to notice you stealing from them. A target may repeat the saving throw once at the end of each turn, ending the effect on a success.
Any target that succeeds their saving throw against this effect is immune to any further attempts by you to use this ability for 24 hours.
Blackjack
When you reach 17th level, you have mastered the art of knocking someone out to steal from them or carry them away. Whenever you have the option to deal sneak attack damage, you can forgo the extra damage to force the target to make a Constitution Saving Throw (DC 8 + Proficiency Bonus + Your Strength Modifier) or be stunned until the end of its next turn.
Once you have used this ability, you must complete a short rest to use it again against the same target.