D&D 5E Can a caster tell if someone saved or not against their spell?

[Blue]

Is there a definitive rule if a caster knows if a target succeeded on a save or not?

The example that came up is someone (a bard) cast Charm Person, which has no visible effect when cast. The target (an enchanter wizard who also has the spell) identified the spell as it was being cast, saved, and acted friendly.

Outside of other checks (deception vs. insight, etc.) is there any inherent knowledge by the caster if the spell save was successful or not in the rules? There was in some earlier editions, but 5e is it's own definition.

Another example could be several targets in fireball, and one takes half damage thanks to fire resistance, not a successful save. Outside other checks, would the caster inherently know that target had failed their save?

 

[prabe]

The rules do not explicitly say either way, but Concentrating on a failed spell is both less supported and less fun to my eye. Really, we've been around in this circle more than once over the years. Always someone says, "Well technically it doesn't say you can't Concentrate on a failed spell..." but never once has someone said "I think it's good game design and fun for the players if they're Concentrating on a failed spell without being able to tell it failed."

I think one of the more entertaining stretches was when a party I was GMing cast Charm Person on someone (who saved), then tried to interrogate him. I think the possibility of failure in out-of-combat spellcasting is good game design, and I think keeping some information hidden can be fun for everyone.

In combats, I put marker-rings on the battlemat, around things that have effects on them; the players (and therefore the PCs) always know which opponents are stunned or charmed or slowed or whatever. Makes it easier for everyone.

I don't think these are mutually exclusive positions. I don't even think they're inconsistent. I think context matters, in both instances.

 

[jgsugden]

The rules do not explicitly say either way, but Concentrating on a failed spell is both less supported and less fun to my eye. Really, we've been around in this circle more than once over the years. Always someone says, "Well technically it doesn't say you can't Concentrate on a failed spell..." but never once has someone said "I think it's good game design and fun for the players if they're Concentrating on a failed spell without being able to tell it failed."

No, but the potential of a PC that recognized a Suggestion spell was cast upon them, but that they made a save against it, pretending to be under the control of the magic is a counterbalancing level of fun. So, even if you disregard the rules, there is a reason to rule that concentration can be given to a spell that is not there.

Regardless, under RAW, there is nothing to indicate that you concentrating is interactive. As such, if the spell is dispelled, fails to take effect, etc... you can still concentrate upon it thinking it is still there, even though there is no spell to concentrate upon.

When I have new players I tell them concentration is using their third arm. Imagine your PC has an invisible third arm. Concentrating on a spell is as hard as keeping that hand above your head. Pretty much anyone can do it, and unless you're smacked around or get too tired to maintain holding it up, you can keep it up without issue. Just as you can hold a hand over your head without it being for a purpose, you can concentrate without it being for a real purpose.

 

[Sword of Spirit]

While I favor not knowing success/failure of spells in general, I don't favor not knowing effectiveness of Concentration.

This is because "Concentration" is poorly named in 5e. It isn't the 3e version where you are actively thinking about a spell. The operating parameters of how it is broken suggest that it is more like a mystical link you are semi-conscious of. You can maintain it through anything but damage, extreme disruption to your physical state, or loss of consciousness. You can be Poisoned, Frightened, Charmed, or even Stunned. You can cast other spells--including ones with extended casting times--establish attunement to magic items, and even rest sufficiently to gain short rest benefit (and I believe an elf could trance through a long rest).

So-called "Concentration" isn't. You don't have to focus on paying attention. It is more like a background app or minimized program just plugging away. The fact that you maintain this state essentially effortlessly without any mechanical action on your part but can choose to end it at any time implies you have a type of awareness of it that allows you to turn it off.

 

[Zubatcarteira]

Being incapacitated drops your concentration, so Stunned does drop it as well. And you can't cast spells with longer casting times while concentrating on something, since casting those requires your concentration through the whole casting time.

 

[Lanefan]

The rules do not explicitly say either way, but Concentrating on a failed spell is both less supported and less fun to my eye. Really, we've been around in this circle more than once over the years. Always someone says, "Well technically it doesn't say you can't Concentrate on a failed spell..." but never once has someone said "I think it's good game design and fun for the players if they're Concentrating on a failed spell without being able to tell it failed."

Of course it's less fun - that's the point. Characters aren't perfect, and every so often they'll make mistakes and should be allowed to do so (and ditto for the opposition!). Concentrating on a non-existent effect is just another avenue for such.

Also, there is I think a considerable difference, both semantic and practical, between an unsuccessful spell (the target was not affected) and a failed spell (which never resolved at all due to being interrupted, countered, etc.). The caster will always know if a spell failed but may often be uncertain if a spell was successful. See the difference?

 

[Sword of Spirit]

Being incapacitated drops your concentration, so Stunned does drop it as well. And you can't cast spells with longer casting times while concentrating on something, since casting those requires your concentration through the whole casting time.

Good catches. I should have looked up Stunned, and I think that other rule had receded so far into my memory (due to never coming up) that I had basically forgotten it. Those examples have a minimal effect on the overall functionality of Concentration I was addressing, but its good to get them clarified.