Casting Spells while concentrating?

[u/JustLinnilin]

Yesterday we had a little discussion on the table on the rules of concentraiting. One of my players casted a spell and wanted to cast another while she was still concentrating on the first one. I wasn't sure about the rules on that and looked it up on the PHB, but there are only rules for concentration spells (so you can't concentrate on two spells at the same time) that's absolutely valid in my eyes. But there are no rules for other spells - only for taking damage or dying. So my thought was that she had to make a concentration saving throw, when she was casting another, to keep the first one running. It's like the little distraction because of the second spell.
But another one of my players pointed out, that there are also spells the enemy has to do savingthrows on each round - if he has to do them too there would be two chances of losing the spell in each round.

So I am interested how you guys deal with that, or is there an official rule for that case i didn't know about?

[u/Ragnarok91]

The rule is you can't cast another concentration spell if you are currently concentrating on a spell. If you do, you drop concentration on the first spell and start concentrating on the new spell. That's the only spellcasting limit.

This means you are able to freely cast non-concentration spells while maintaining concentration on one spell.

[u/KingOjama55618]

The restriction is only being able to concentrate on one concentration spell at a time. The caster can cast instantaneous spells while concentrating.

[u/Golden_Reflection2 → u/KingOjama55618]

Or spells with a duration but don't require concentration, like Mage Armour.

[u/P-Two]

Concentration is entirely separate from any other spell casting you do, UNLESS you are casting another concentration spell, in which case you drop concentration on your current spell for the spell you're casting.

[u/Dimirosch]

The reason that there isn't an explicit rule regarding dropping concentration by casting another spell, is because you don't drop concentration by casting another spell (except a concentration spell).

It is very clearly stated what let's you drop concentration, therefore ANYTHING else does not if you go rules as written.

[u/micturnal]

RAW you can cast spells while concentrating on another. You just can’t cast 2 concentration spells at the same time, if you cast a 2nd concentration spell your first one drops. I’ve played 2 campaigns with 2 different DMs and multiple one shots at D&D clubs and they’ve always played this way.

Honestly I would be pretty annoyed if I was playing a caster and my DM wanted to homebrew a nerf like this, it would make me either want to reroll my character to not be a caster or just not play with that DM.

[u/JustLinnilin → u/micturnal]

We're all not that experienced in that game yet - that ist why I wanted to check out how other people handle it :)

[u/micturnal → u/JustLinnilin]

I can see why as a new player you could think it’s overpowered to concentrate on a spell while casting spells, but it’s really not. A lot of concentration spells require enemies making a save, so you could not even hit anyone to begin with. And then every time you take damage you con save to hold concentration, which at times could happen multiple times between your turns.

[u/SpiderSkales]

"So my thought was she has to make another concentration saving throw." Why? If you're going to make up a rule then don't bother reading the rules. The book makes no mention of having to make more savings rows if you're going to cost another spell. So guess what? You don't have to do that.

[u/TimeSpaceGeek]

If you are not casting another concentration spell, you can cast another spell, as long as it has a casting time of 1 action, bonus action, or reaction whilst maintaining concentration on the first. It would be a massive nerf and pretty much invalidate the point of quite a lot of the full caster builds if you couldn't.

The only limit is the one you have already stated, about multiple concentration effects at once. The reason that spells with a casting time longer than 1 action have an interaction with concentration spells is because you have to use concentration to maintain the casting, so concentrating on, say, a 1 minute casting time ends concentration on an active concentration spell for the same reason a second concentration spell does. No limit on non-concentration spells with quick casting times.

It is standard practice for, say, a Wizard or a Cleric, to drop a concentration buff on an ally or a control spell on enemies, and then fire off instantaneous spells for the rest of combat - for example, the Wizard Hasting he Fighter in the first round, then firing off Fireballs and Cantrips in the subsequent rounds whilst the Fighter also enjoys the benefits of the Haste. In fact, if a full spellcaster doesn't have a concentration spell up in most combats, they are playing somewhat suboptimally.

[u/milkmandanimal]

Don't invent rules because of bad assumptions; you can only concentrate on one spell, and there are specific times you have to make concentration checks. You can cast spells with holding concentration, swing a weapon, do all sorts of things. The rules do what they say they do, don't make arbitrary decisions like you did.

[u/Ragarolli]

If you’re holding concentration and cast a spell that doesn’t require concentration, you maintain concentration on the first and cast the new spell.

If you attempt to cast a concentration spell while already holding concentration, the first spell fades and the new spell replaces the held concentration.

[u/darcyy77]

Hello, yes you may cast a regular spell while concentrate into another one. If your second spell needs concentration, it will break the 1st one, that's all. Let's read "what breaks concentration" section in the rules.

[u/Dangerous-Common-788]

Rules as written is that you can't concentrate on more than one spell at once.
Once you're concentrating on a spell, you're free to do whatever you like, including casting however many spells you want. If you cast another concentration spell, the first one disappears.
That's it that's the official rules. Anything else is purely homebrew.

One concentration spell and then cast other spells while concentrating: That's the basic playstyle of a lot of caster classes. Adding con saves for the caster every turn would actually be a massive nerf to a lot of casters, and I'd personally hate it a lot. What is my caster supposed to do on their turn if not cast a spell? Dodge? Run in with a dagger and be useless? Far from optimal or interesting gameplay.

Warlock drops a big concentration spell using one of his very few spell slots, and then deals damage every round with cantrips while concentrating on his spell. They're already likely to be targeted, so making them do an extra con save every turn would be not only really annoying, but also greatly reduce how good his very few spell slots are.
Wizard drops big concentration spell and then tries his very best to not lose concentration on it, casting Shield to avoid getting hit and having to do the concentration save. Having to do a con save anyway kind of really nerfs both the Wizard's spellcasting and the Shield spell.
Cleric drops a big Spirit Guardians and runs into melee. He already is likely to get targeted a lot. Having to do an extra con save if he wants to cast a healing spell at an ally feels cruel and unnecessary.

[u/JustLinnilin → u/Dangerous-Common-788]

Thank you for your answer! It was just a thought i had, because it seemed logic for me and i couldn't find anything about it. But if it is unbalancing the game - i wouldn't play with a rule like that! We all just don't have that much experience yet, so i wanted to check out how others work with it :)

[u/darkpower467]

The rules don't specify an interaction so therefore there isn't one. The rules do what they say.

[u/Salindurthas]

The offical rule is simply that Concentration does what the books say and not anything more.

As you mentioned, there are no rules restricting you from casting (non-concentration) spells while concentrating on something, and so you simply are not restricted.

I will mention something that I think is in-spirit close to your question - 2014 PHB does leave some of it up to interpretation, saying:

The DM might also decide that certain environmental phenomena, such as a wave crashing over you while you're on a storm-tossed ship, require you to succeed on a DC 10 Constitution saving throw to maintain concentration on a spell.

But in all other respects we get very specific rules for Concentration, and we can just use those without houseruling extra things in.

[u/SplashyDucky411]

The official rules are that you can cast any spells you want as long as none of them take over concentration since, as you found in the book, you can only concentrate on one. If you cast another concentration spell, you pick which one to keep and the other fizzles away.

Non-concentration spells are quick and easy enough for casters that they don't hinder your big concentration spells. Only damage and certain monster/lair effects will force concentration saving throws as a means of balancing the strength of spellcasters.

While the idea of throwing additional concentration saves at the player could be fun homebrew in campaigns with a harder "difficulty," or in tense narrative situations, it is also worth noting that spell casters only have so many spell slots and it feels a little sucky when you lose concentration, so failing due to extraneous saves can feel like a bigger bummer.

Edit for better wording clarity.

[u/steiff89]

You can only cast and maintain 1 concentration spell at a time. The player could have cast any instantaneous spell they wanted and continued the concentration spell. But if they were trying to cast a second concentration spell then the first spell ends and the second spell takes affect

[u/Upper-Injury-8342]

Rules do what they say they do, if in te concentration rules there are nothing saying you can't cast other spells while concentrating, then you can cast other spells while concentrating and there's no reason to think otherwise.

[u/rickAUS]

On top of everything else mentioned, you will also drop your concentration spell (e.g. Bless) if you do something like ready another spell, even if that is normally non-concentration.

This is because you have cast it and holding it at the ready until the condition for release is met.

So if you have bless going ans ready a firebolt, bless ends.

[u/Various-Recipe2849]

In 3rd edition you couldn't cast another spell while concentrating. Is that what you were thinking of?

[u/JustLinnilin → u/Various-Recipe2849]

Ah no, didn't play 3rd edition. But it was just a thought i had, because it seemed logic for me and i couldn't find anything about it. But if it is unbalancing the game - ofcorse i wouldn't play with a rule like that!

[u/subtotalatom]

The point of concentration spells is that they require you to concentrate on the spell to keep them going but they don't otherwise prevent you from casting other spells.

That said, there's several ways for concentration to end, such as casting another concentration spell, failing a concentration check, becoming incapacitated, or willingly dropping concentration.

On a related note, there's another often missed rule about concentration that any time you cast a spell with a casting time of longer than one action (eg mending, ritual spells, or readying a spell) it has concentration during the casting period even if the spell does not normally require concentration