[Optional Rule] Knockout Blow

[hawaiianbrian]

I need some feedback on an optional rule I'm considering implementing. It would allow someone (of any class) to knock out a surprised enemy.


Knockout Blow: When you take the Knockout Blow action, you may bypass the hit points of your target by making a quick and unexpected attack. Select a target that has no reason to expect an attack from you (perhaps because they don't know you are there, trust you, believe you aren't a threat, etc.). If your first attack on that target hits, roll damage for your weapon. A critical hit does 2x damage as normal. The target then must make a Constitution saving throw with disadvantage, where the difficulty class is equal to your damage. Rogues may use their Sneak Attack ability with Knockout Blow only if their target is totally unaware of their presence and/or has no reasonable expectation of an attack from you. As usual, the DM is the final arbiter of when a target is subject to this action.


Thoughts? I know it's powerful, but the right circumstances for this action shouldn't come up too often. I picture it used against guards, thugs, or in cases of shocking betrayal (et tu, Bruté?). Perhaps a modification that the target must be lower level than you?

 

[Dausuul]

A Con save at disadvantage versus the damage inflicted is an almost guaranteed knockout; I would expect PCs to go to great lengths to set this up. Every major encounter, the party would be trying to sneak in the rogue under invisibility to Knockout Blow the boss before the fight.

What problem are you trying to solve here? Under the rules, you can already declare you're dealing nonlethal damage to knock an enemy out when it's reduced to 0. What scenario does that not cover that this maneuver would?

 

[hawaiianbrian]

I like the idea of stealth-style infiltration where success largely depends on knocking out guards swiftly and quietly. With the normal rules, that's basically impossible unless all the enemies have less than 10 or so hit points, which means only in low-level games basically. It also just makes sense to me that hitting someone with an unexpected attack (I'd make sure this is delicate and hard to pull off all the time) is more effective than engaging them in battle.

A few tweaks after running this by others:

• Certain types of creatures are immune: elementals, undeads, constructs, oozes, any creature immune to stun, and possibly others depending on circumstances.

• The target must be of lower HD than you (no knocking out the Legendary Lord of Eternal Chaos as a lowly 5th level fighter).

• This action doesn't work during combat rounds except in cases of betrayal, such as when an ally unexpectedly attacks another ally.

I'm open to other ways of expressing the saving throw, or perhaps a different approach, like an automatic knockout if the damage exceeds their CON score, etc.

 

[transcendantviewer]

I'm with Dausuul on this one. This rule does feel somewhat superfluous. A rogue's Sneak Attack is already pretty devastating as a "Put them down" tactic. You as a DM can allow whatever you'd like at your table, but this seems like it'd only be necessary for narrative flair, and that's something you can just ask your players about. For instance, they are taken by surprise because the plot requires such a thing. Ask your players if they're okay with just moving the game along, or if they want to actively fight their capture. This rule seems unnecessary, especially when things such as hit points exist.