Possible Homebrew Feat (How viable is this?)

Prerequisite: Having the Rogue's Sneak attack ability

Effect:  You gain a +1 to your STR score not to exceed 20.

You may now treat your unarmed strikes (only for bludgeoning damage), a club or a light hammer as a finesse weapon and thus use those weapons to do sneak attack damage if your are proficient with them however you may not do lethal damage and if your target is brought to zero or below by the attacks then it is automatically stabilized and unconscious.  You may not choose to use the attack to kill the target.  Furthermore, if they are brought to zero or below by another attack then they are not killed unless enough normal damage is done to bring that target to zero without the damage done by the character with this feat.  Upon taking damage that is not affected by this feat the target wakes up and may act regaining hit points as if they had taken a short rest.

{OOC:  The point of this feat is to allow the existence of Thugs, strong rogues who can knock out their enemies if they can get the drop on them but do not have to worry about killing the target.  Useful to avoid a murder wrap}

I know 5e does not have subdual damage so I am attempting to keep with the mechanics they utilize to incapacitate someone.  I am keeping this to only bludgeoning weapons as they are most likely to be used for knockout but the club hammer etc. may have to be wrapped in cloth at the DM's direction for this to work.

The only issue is the complication of keeping this damage separate but this is to keep in line with the spirit of the feat being designed to knock out not kill.  If the character takes them out and then stabs the target to kill them this is not in line with the intent but the rule may be too clunky.  The idea behind this is to add this dimension to the game as it appears not to be there.  Any thoughts?  Can it be improved?

It would be difficult to track how much damage the rogue does compared to how much is “normal damage.” Also, doing nonlethal damage with a melee weapon or unarmed strike is already possible in this edition simply by declaring that’s your intention.* It only matters if the last hit itself is “nonlethal.” If they gank the unconscious enemy after that it’s up to them. 🤷‍♂️ 

*https://www.dndbeyond.com/sources/basic-rules/combat#KnockingaCreatureOut

Knocking a Creature Out

Sometimes an attacker wants to incapacitate a foe, rather than deal a killing blow. When an attacker reduces a creature to 0 hit points with a melee attack, the attacker can knock the creature out. The attacker can make this choice the instant the damage is dealt. The creature falls unconscious and is stable.

The real point of the feat is to allow a rogue to use a one handed bludgeoning weapon to do sneak attack damage all the other is really describing how to used to incapacitate rather than kill. Doing that (bludgeoning weapon sneak attacks) is probably a strong enough advantage that it is all the feat should grant - no +1 to strength.

Ehh…, they can already do Sneak Attack with a rapier or a dagger, what real advantage is there to doing it with a club or hammer? It’s not as if the damage type really matters much this edition.

Actually it does because unarmed attack is not finesse and that is the other aspect of this feat.  I appreciate the information on doing non lethal, I had not seen that.

The idea is to have a character that can go up behind the guard and knock him out sending him unconscious.  As a DM I would not allow you to do that with a scimitar or a daggaer.  There is no bludgeoning finesse weapons as the weapon list is now really shortened, not even brass knuckles or guantlet.

To my mind the point of this feat is to allow the user to do non-lethal sneak attack damage with bludgeoning weapons. Evidently 5e wanted to limit it to this light piercing and slashing weapons so in line with that what this feat does is essentially allow you to add three bludgeoning weapons to the finesse list meaning that even without being a rogue you can still use dexterity instead of strength to use them and to allow sneak damage with the weapons but only of the attacks are non lethal.  

The idea is that this allows the one shot attack to knock the guards out and not kill them, a trope for the heroic rogue fighting the evil but sparing the innocent henchmen etc.  This is the only way that one can use this to get sneak damage with an unarmed attack.  Feats such as tavern brawler or the fighter unarmed fighting style can elevate the damage to d4, d6 or d8 etc. making that viable.  It just does not sit well with me that you cannot put a strong rogue with multiclassed fighter levelvs or combat based rogue archetypes that cannot use his hands to essentially suckerpunch people.

A good example for a character like this would be the "pugilist" from the movie Young Guns.  The little guy, quick with his hands who is a trained boxer that can beat someone twice his size.  Essentially I see him as a Rogue with the Swashbuckler archetype with unarmed damage from a fighting style from multiclassing or a feat.  Swashbuckler has an option where you can get your sneak damage when  fighting an opponenet alone, both you and him are not in 5' of others to help.  This works for characters that fight in professional bouts and can illustrate a character so well trained they can knock someone out one an one.

To me doing nonlethal peircing damage with a dagger makes no sense.  You would have to use the flat of the blade but that to me would mean it would not wrok with a finesse attack as the dagger is not made to be used like that.  A balled up fist or a club is so there should be a feat that allows you to use it in this manner.  That is the necessitty for it as you can not do that with the rules of 5e as is so I am thinking about adding this as a homebrew.

If the feat were structured to read that you had to pick one of the weapons, unarmed, club or light hammer and it only worked for that weapon, i.e. you train to use it as a finesse weapon to knock someone unconscious would that still justify a +1 STR or would that still be too much and it better just allow the three weapons to be used as finesse weapons in this manner?

RAW they can knock someone out with a dagger or rapier, one supposes by using the but end to cudgel them and knock them out, and it can use sneak attack and still do it’s damage die. 

Might be through a technical view of the rules but the butt end of a scimitar in my estimate would not be finesse since that would be an awkward way to use the weapon.  It just does not feel right story wise.

I was just letting you know that the rules already allow for such knockouts as you described. What you choose to do with that information is entirely up to you. 🤷‍♂️

No No I get it, just thinking out loud.  

Update to Possible Homebrew Feat (Based on discussion so far)

Prerequisite: None

Effect:  Normally Unarmed attacks, Kight Hammers and Clubs although light weapons are not ones that allow the use of the finesse capability untrained.  You have taken time to master the intricacies of the use of these bludgeoning weapons allowing them to have the finesse trait when in your hands.  This means you can use your dexterity bonus instead of your strength bonus to hit and if you have the sneak attack ability you may use this in conjunction with these weapons as you can with other bladed finesse weapons.  However, in using these weapons in this way it is difficult to apply the full force normally associated with bludgeoning weapons.  This means that all strikes with these weapons while using the finesse properties are not lethal and if you bring your target to zero or less, they stay at 0 hit points damage and automatically stabilize and are knocked unconscious as per the rules relating to non-lethal damage. 

There this incorporates your suggestions into refining the idea.  Anyone still having comments please leave them.

You could simplify that greatly. Try this:

You can use Dexterity instead of Strength for attacks you make with a club or light hammer, and if you have the Sneak Attack feature you can add your Sneak Attack damage to the damage rolls made with these weapons. When you do so, if the target of the attack is reduced to 0 hit points it falls unconscious but remains stable.