Could the spell Command make a target drop concentration?

Question

The fighter/warlock in our party tried to make a creature drop concentration with Command, by saying "stop".

The target was not an enemy. Whether stopping concentrating would be harmful to the target is debatable, but outside of the scope for this question.

This first level spell states:

You speak a one-word command to a creature you can see within range. The target must succeed on a Wisdom saving throw or follow the command on its next turn. The spell has no effect if the target is undead, if it doesn't understand your language, or if your command is directly harmful to it.

Some typical commands and their effects follow. You might issue a command other than one described here. If you do so, the GM determines how the target behaves. If the target can't follow your command, the spell ends. [...]

The spell suggests it could work, under GM's discretion. But I'm wondering whether the word "stop" would be clear enough, by RAW.

Additionally, if possible, what would be a better word to use to make someone drop concentration using Command?

Answer 1

The GM determines how the target behaves.

No one but the DM running your game can tell you what effect a particular command will have, because the spell states:

the GM determines how the target behaves

I can tell you what I would rule in a particular circumstance, but I have little confidence that my ruling will reliably predict any other DM's ruling, because the rules here give the DM full liberty to determine what happens, and no guidance at all for making that decision. The rules-as-written answer is that there is no rules-as-written answer. The rules themselves recuse themselves of any decision making responsibility in this instance.

That said, I would not expect "stop" to be a great choice of command in most instances, due to the ambiguity. Stop what? Stop breathing? Stop fighting? Stop right there criminal scum? When you use an off-label command, you're just rolling the dice (figuratively) on the DM's interpretation of the command, especially with one as vague as "stop".

Answer 2

Don't look for a word, look for an agreement with your DM

You say

But I'm wondering whether the word "stop" would be clear enough, by RAW. Additionally, if possible, what would be a better word to use to make someone drop concentration using Command?

But Command says (emphasis mine):

You speak a one-word command to a creature you can see within range...You might issue a command other than one described here. If you do so, the GM determines how the target behaves.

You may be under the impression that the 'better' your word is, the more likely your DM will be to rule that it 'works', and if only you can find the 'perfect word', then the NPC would have to break their Concentration by following the Command. But that's not how the spell works; the appropriateness of the word is not relevant (you might say the word itself is fluff, not crunch).

Consider the "typical commands and their effects" in the Command spell - Approach, Drop, Flee, Grovel, Halt. Note that none of them have to have the result they do under RAW based on the nature of the word itself; rather, the game designers decided on an outcome that was appropriate for the power level of the spell and then used them as model examples for DM's and players. Suppose one of these specific words had not been included in the spell description, and a player was presenting it as a novel word "other than the one described", but the DM considered the suggested effect too powerful:

Player: "I'd like to use Approach to have the target move toward me by the shortest and most direct route, and end its turn if it moves within 5 feet of me."
DM: "Command allows a single word only - what you are describing is "Approach (me)". How does the target know who or what to approach? And why do they end their turn? They have only used movement and have all their other turn options."

Player: "I'd like to use Drop to have the target drop whatever it is holding and then end its turn."
DM: "Command allows a single word only - what you are describing is "Drop (things held)". How does the target know not to "Drop (self)" and fall prone with their items still in hand? And why do they end their turn? Dropping things is a free action - what you are describing is more like 'Drop and Halt' put together."

Player: "I'd like to use Flee to make the target spend its turn moving away from me by the fastest available means."
DM: "Command allows a single word only - what you are describing is "Flee (from me)". How does the target know not to Flee from one of your teammates, or someone in their own party, or their home?"

My point here is that none of these words inherently force the condition on the target by the nature of the word itself. Instead, they were considered appropriate effects and then the word was chosen in the rules as representative.

As a further consideration of how your well-intentioned search for a 'better word' is actually misguided, consider the difference between English and the in-game language. In English, there is not a great single word for the command 'Stop concentrating!' In Spanish, however, I can say Desconcentrense! and it is quite clear. The word actually used by your caster is not in English or Spanish however - it might be in Common, or Gnome, or Draconic. Under Rule 1 ('the DM describes the environment'), it is the role of the DM to decide the vocabulary of these imagined languages within their campaign world, and also to decide whether or not there is an appropriate word. There might not be one at all; there might be one that not only works, but furthermore unambiguously distinguishes between simple mental concentration and concentrating on actual spells. So, even if you could find a 'single word' in English to use as a Command for someone to drop concentration, the DM is well within their purview to say that such a concept does not exist as a single word within the language the caster is actually using in the game (and conversely, even if there is not a single word in English for the effect you desire, there is nothing to stop the DM from ruling that your caster's language does contain such a word).

So, rather than looking for a better word, first go to your DM and ask whether it would be acceptable to have a successful Command result in the effect you want, failed concentration.

If your DM does approve this effect, then work with them to choose any word that evokes that feeling, but realize that the word itself is just for immersion and descriptive flavor, not inherent power or to fulfil some rules requirement. I would suggest words like Disregard, Neglect, Detach, Overlook, Disconnect, Ignore, Unheed (or Misheed). The DM might even say, "Okay, in play your command will be 'Stop concentrating!' but don't worry that it is two words in English; it is only one word in Common!"

A note on power level
As Gabe notes in their answer, sleet storm at 3rd level is the lowest-level official spell that provokes concentration loss independent of damage, so your DM might be hesitant to allow a first level spell to disrupt concentration on a single failed save. In such a case, it is worth pointing out (as this answer in the Q&A linked by Gabe does) that the PHB core first level spell Hideous Laughter, on a single failed Wisdom save, results in the target being prone and incapacitated, and one of the effects of the incapacitated condition is automatic loss of concentration (even though the condition description does not mention that). Now, Hideous Laughter and Command are on the spell lists of different classes, so it is not a direct comparison, but at first level Hideous Laughter with a single failed save imposes both the prone condition and the incapacitated condition (including loss of concentration), and both for potentially multiple rounds. Compared to that, allowing Command to result in a next-round loss of concentration with the same Save is hardly overpowered or unwarranted.

Answer 3

This is unlikely to work

Of course, your DM can decide upon it, and may decide something works, but it is not easy to see how.

These are the only ways you can end concentration:

1. The caster can willingly end it.
2. Casting another spell that requires concentration.
3. Taking damage.
4. Being incapacitated or killed

Ask them to willingly end concentration

The best bet is to ask them to willingly end it. Your problem is that you only have one word, so you cannot say "stop concentrating". What are the antonyms of "concentrate" in the meaning of to fix (as one's attention) steadily toward a central objective? Merriam-Webster has none. The Oxford languages thesaurus comes up with:

daydream

So you could try that and hope your DM plays along. "Stop" won't cut it, as you are not telling them what to stop. There is also the Halt command, which seems to be pretty equivalent, they might just end up doing that, and that does not end concentration.

As for the other options:

Ask them to cast another concentration spell

You could try "cast", and hope that they only have other concentration spells memorized. This could actually work, but it is highly unlikely. All you'll likely achieve is getting pelted with a cantrip. Specific spells that can be used as a verb might work if you suspect they have them, e.g. towr suggested "fly!".

Ask them to hurt or kill themselves

Asking them to deal damage to themselves or to commmit suicide will not work because command says:

The spell has no effect if the target is undead, if it doesn't understand your language, or if your command is directly harmful to it.

Ask them to incapacitate themselves

Asking them to incapacitate themselves (if you could even do so in one word) would likely also not work. The conditions that come with being incapacitated such as being stunned, paralyzed, petrified or unconscious are not things you can typically inflict on yourself without harming yourself either.

So, in summary, there are likely no good words to achieve this in a single word.

Answer 4

RAW, only the words listed in the Command spell description have game-determined effects, otherwise it's the DM's decision. In this case, "stop" can be a synonym for "halt" so you may get this effect:

The target doesn't move and takes no actions. A flying creature stays aloft, provided that it is able to do so. If it must move to stay aloft, it flies the minimum distance needed to remain in the air.

This wouldn't break concentration (probably), since concentration doesn't require an action to maintain.

Or maybe they would stop doing something else. Talking? Casting their spell? Making poor life choices? (Nah, not the last one.)

The description for concentration doesn't give so many options or hints other than that concentration can be broken by casting another concentration spell, taking damage then failing the save, or being incapacitated or dead, and the last two are rendered impossible by Command itself not allowing directly harmful effects.

Asking them to cast a concentration spell is a pretty good option, though it is very situational. You could ask them to Bless, Hex, Fly or Haste. If you're wrong and they can't do the spell, you've wasted your Command.

Other than that? There's no more information in the description of concentration that would help. Maybe you can trigger one of the DM-specified concentration-breakers. This is your DM's domain.

But maybe, just maybe, the caster could forget what they're doing?

Answer 5

Thomas's answer is excellent and very true - I think of it like a wish spell in that if you're not going to go with one of the pre-fabricated options, the result is entirely in the GM's hand.

To address your other question "what would be a better word to use to make someone drop concentration using Command?", personally I like "neglect". Of course, it's still very much up to the DM what they neglect, but I think it's just slightly less ambiguous than stop.

A mechanical reason a GM might deny a quick and easy way to force the enemy to lose concentration is that command is a 1st level spell and would enable what is clearly a very effective strategy. The closest examples to this are spells like Hideous Laughter, Sleet Storm, Earthquake, and Storm of Vengeance (1st, 3rd, 8th, and 9th levels respectively) which interfere with concentration outside of just dealing damage, and that's before considering spells like acid arrow (2nd level) which was created specifically as a way to deal continuous damage to increase the odds of disrupting concentration. As a side note, the most game-changing original spell in the OGL-based video game Solasta: Crown of the Magister is "Annoying Bee", a cantrip specifically meant to disrupt concentration. There's a reason WotC have never included a similar cantrip into official material, despite how much fun it would be to pelt the evil wizard with bee-hives.