There is no coup de grace mechanic in D&D 5e like there is in previous editions. So how is a helpless opponent dispatched quickly, mechanically? Is it just a matter of giving the opponent advantage?
It seems like one should be able to deal with someone who is under the effects of a sleep spell, for example, more quickly than just what a to-hit bonus enables.
Quoting basic rules (same as PHB)
An attack against an Unconscious or Paralyzed creature has advantage and is a critical hit if the attacker is within 5 feet. Against a restrained opponent (e.g. tied up), they just have advantage.
This can cause death under the Instant Death rule (p. 79).
Massive damage can kill you instantly. When damage reduces you to 0 hit points and there is damage remaining, you die if the remaining damage equals or exceeds your hit point maximum.
Against an Unconscious Opponent (p. 79).
Damage at 0 Hit Points. If you take any damage while you have 0 hit points, you suffer a death saving throw failure. If the damage is from a critical hit, you suffer two failures instead. If the damage equals or exceeds your hit point maximum, you suffer instant death.
So 1 adjacent opponent will cause 2 failed death saving throws - one more and you're gone (which could be the one you have to make on your turn).
Considering your sleep spell question - under RAW there is no way to dispatch a sleeping opponent without risking their waking. You can attack with advantage and get a critical hit - this may render them unconscious (or kill them outright) but if it doesn't then they will wake up. Given the description of the spell this seems fair enough, getting into a position where you can slit their throat is likely to jostle them enough to wake them before you do so.
Remember, all this occurs during combat conditions - you can't concentrate exclusively on the helpless creature and still look out for danger.
Parenthetically, this is normally only an issue for unconscious PCs, unconscious monsters are normally dead (Monsters and Death, Basic Rules, p. 79). A fair enough rule in my opinion as going around the battlefield dispatching unconscious opponents provides little role-play opportunity, doesn't advance the story and is a little bit ghoulish.
Coup de Grace is not gone, it's just not explicitly called out.
Unconscious....Any attack that hits this creature is a critical hit if the attacker is within 5 feet of the creature (PHB 292)
This same wording is also used for Paralyzed.
You don't have this mechanic potentially leading to automatic death (though it can with the already in place death rules), but it is an automatic critical hit which should stack on a good bit of damage.
So how do you deal with a helpless opponent? If they are paralyzed or unconscious, you can hit them and get an automatic critical (And you have advantage to attacks against them too).
In 4e, you could only be targetted by a coup de grace if you had the 'helpless condition'. Usually, this only happened when you fell unconscious.
In 5e, there is still a coup de grace mechanic, when creatures are subject to certain conditions, attacks that hit them will automatically be critical hits. There are two effects in 5e that allow an attacker to automatically crit.
PHB 292:
Unconscious
- An unconscious creature is incapacitated (see the condition), can’t move or speak, and is unaware of its surroundings
- The creature drops whatever it’s holding and falls prone.
- The creature automatically fails Strength and Dexterity saving throws.
- Attack rolls against the creature have advantage.
- Any attack that hits the creature is a critical
hit if the attacker is within 5 feet of the creature.
PHB 291:
Paralyzed
- A paralyzed creature is incapacitated (see the condition) and can’t move or speak.
- The creature automatically fails Strength and Dexterity saving throws.
- Attack rolls against the creature have advantage.
- Any attack that hits the creature is a critical hit if the attacker is within 5 feet of the creature.
If the victim is truly helpless, then they can just kill them with no roll necessary. Common sense should always trump the rules. (Basic Rules, p. 4)
...a dagger deals 1d4 damage, and these types of players rarely extend the logic to say "I stabbed that 13th level fighter with a knife, why isn't he dead?".
This is a common and basic misunderstanding of how HPs are/were intended to represent the combat stamina of a creature.
Originally, they were a design compromise1 in Gygax & Arneson's "three little brown books" to measure the combat stamina of a creature within a fight, borrowing heavily from their joint background in tabletop miniatures wargaming. Not only do HPs measure a creatures ability to take physical punishment (wounds) but also their ability to keep moving/dodging/weaving/parrying/mental will/morale fortitude (combat stamina - ability to stay in a fight). Thus, it is a conglomeration of homogeneous fighting concepts represented by a single number. This conglomeration was explained in some detail in the AD&D 1e DMG by Gary Gygax (also found in this asnwer at RPGSE).
HP is a single number which unfortunately does not take into account the slow degrading of a creatures combat stamina over time - a creature can fight at 100% optimal fighting ability from 100 HPs to 1 HP before becoming suddenly combat ineffective (dead? unconscious? exhausted?). I hope this explanation helps better understand that HPs in D&D are not just "the sum of all wounds".
1 A pre D&D citation of the early stage of HP in Blackmoor
There's a lot of gameplay balance reasons to limit the ability to perform autokills on helpless opponents in combat. A variety of interesting spells at lower levels would become completely unbalanced if you followed the (admittedly common-sense) approach of allowing anyone with a knife to autokill a helpless opponent. Hold Person and Sleep begin to simulate Power Word: Kill under this framework.
Certain groups of players will protest "what's so difficult about this, I just slit his throat", and that's a fair enough appeal to realism, but if this is what you're up against it may be worth having a chat with the group about how far the realism goes - after all, this is a game where combat is turn-based and a dagger deals 1d4 damage, and these types of players rarely extend the logic to say "I stabbed that 13th level fighter with a knife, why isn't he dead?". So I would say that in combat, a suspended sense of logic applies, where people occupy 5-foot squares, act sequentially, and can stab each other half a dozen times before they keel over. In this alternate logical framework, even if an opponent is helpless, they cannot "simply be dispatched".
Outside of active combat, it's true that a group of people whaling on a tied up prisoner with weapons for a full half-minute trying to kill him is ridiculous and undignified, so I would just say that in combat the RAW apply, and out of combat I would allow execution without checks. And just try to design your adventures such that the PCs aren't often put into situations where they think the most fun and heroic thing to do is to execute helpless foes.
A fair enough rule in my opinion as going around the battlefield dispatching unconscious opponents provides little role-play opportunity, doesn't advance the story and is a little bit ghoulish.
I don't know, the last time a player at my table grimaced reluctantly and said "[his character, TiefWiz] draws her knife and sets about her grim work" thus performing the coup de grâce on four sleeped goblins (I didn't ask for any rolls because I am sane), it really emphasized the delightful moral ambiguity at the heart of D&D. I like that it has so many problematic assumptions (so many of the games' underlying premises and so much of its history are racist that it's hard not to make fun of it while DMing certain modules, even with children present!) because it's an opportunity to confront and subvert those tropes... or not. Because it's your table and if you're an OG, you're an OG, respect.
Anyway I think leaving out these details sanitizes the violence, which is the opposite of how violence or warfare (D&D is a hack of a WAR-GAME) should ever be portrayed: I want my D&D to be more Dark Souls meets Full Metal Jacket than Star Wars meets Lord of the Rings.
(And D&D was always 70% Conan/Elric/Vance and 30% Tolkien at most, anyway.)
Also perhaps more important than any of that? I never suggested that they slit the throats of the sleeping subhumans. I actually didn't even ask them what they were going to do with the sleeped goblins. The party had an internal discussion and decided to cold-bloodedly murder them based on the assumptions of the game. Maybe I should have challenged them on that, but as the six of them had come to a consensus, that would feel like being a shitty DM. The morality, or lack thereof, of D&D, is interesting, if not important.
(Party of 6 was collectively strongly Chaotic Neutral. For the few CG characters, I didn't give them any grief. Goblins eat babies. It is known.)
