Enforcer

In the criminal underbelly of the world, not all use their cunning and guile to get by. Some especially dangerous individuals use their overwhelming strength and presence to rule the underworld - to keep the law of thieves. Few who encountered an enforcer live to tell the tale and those that do tend to keep what's left of their mouths shut.

Skull Cracker

When you choose this archetype at 3rd level, you gain proficiency with intimidation and athletics skills if you do not already.

Additionally your unarmed strikes and two simple or martial weapons become proficient. These weapons are now able to be used in conjunction with your Sneak Attack feature.

Your unarmed strikes become 1d6 + Dex

Manhandle

Additionally, at 3rd level, you can use Cunning Action feature on your turn to attempt to shove a creature.

Overwhelming Force

Starting at level 3, you know how to exploit numbers to give yourself an advantage in combat. If a creature has already been attacked in the round you can exploit its moment of weakness defending itself to gain sneak attack.

Armor Cleave

Starting at Level 9, you have learned the art of applying strength to minute weak points in armor builds. As an action, Make a strength throw against the AC without ability modifiers against an enemy. On a success their Armor is broken and is treated as not being equipped. This does not work if they aren't wearing armor but does work against natural armor. This effect lasts until the Armor is mended.

Limb Breaker

Starting at level 9, you know how to deal with troublesome foes.  When you make a melee weapon attack that has sneak attack you can suffer a - 5 to the attack roll to target a specific body part. If you damage equating to half your Rogue level rounded up or more that body part is crippled and remains so until the person receives healing equating to half the damage dealt. You can use this feature an amount of times equal to your strength modifier (minimum 1) and regain all uses on a long rest.

Your saving throw DC for the effects is 10 + your Strength modifier + half your proficiency rounded down. 

Target effects 

• Arm - They must succeed on dexterity saving throw or they drop whatever they are carrying in that hand and can't cast spells with somatic components. On a pass or fail they have disadvantage on attacks using that hand and can't benefit from using a shield on that hand.
• Leg - They must roll on a constitution saving throw. On a pass their movement is halved until the injury is healed. On a fail their movement becomes 15 feet, they have disadvantage on Dexterity saving throws  and can't take the dash action.
• Head - They must succeed on a constitution saving throw. On a pass they can't concentrate on spells. On a fail they can't concentrate on spells, take reactions and are stunned until the end of the round. 

King Hit

At 13th level, you learned to exploit the drop in a mark's guard. When you hit a character with your Sneak Attack feature, that creature must make a Constitution saving throw against a DC of 8 + proficiency bonus + strength or dexterity modifier. On a failed save, the creature becomes stunned until the end of their next turn.

You can use this feature a number of times equal to your strength modifier, and regain all uses after a long rest.

Zero 'Em

At 17th Level, the work might be dirty but you always finish the job. When attacking a creature that it either prone, stunned, or frightened your sneak attack damage increases by 4d6