D&D 5E Re-opening discussion on multiple spell concentration.

[Tom Donovan]

I added a rule recently (which none of my players have yet tried).

You can concentrate on multiple spells at the same time. Each concentration spell beyond the first incurs a cumulative -5 penalty to concentration checks. When you cast a concentration spell while concentrating on other spells, you must immediately make a concentration check or lose concentration on all spells except the one you are casting. If you are damaged, you make one check for all spells you are currently concentrating on.

This makes it a risky maneuver rather than something to be spammed every encounter. If you need to try, you can attempt it, but it is never guaranteed. I'm fine with the idea in concept, but I don't feel that the rule for it should be so generous that it is regularly attempted (unless perhaps a feat is involved).

Yeah, I usually try to be the sort of dm that says, "Sure, give it a shot." And, then adjusts the difficulty to be reasonable.

 

[Krachek]

At our table Concentration is the #1 rule we misplay.
Forget check on damage, forget to cancel spell when cast another concentration, wrong timing of spell duration.
So I suggest you to keep any additional rules very simple.

A feat is the simpler way.
To start make a feat that allow to choose 4 spells that allow MSC.
It need a try out.

 

[cooperjer]

The rule that I use for my home game and I enjoy is to allow all spell casting characters to choose a spell as their signature spell. This spell must be 2nd level or lower and not cause more than 1d6 damage per turn. This allows the obvious spells of Hex and Hunters Mark, but also allows Phantasmal Force. A spell caster can concentrate on their signature spell plus one of any other concentration spell if they wish. The rest of the rules on concentration apply, i.e. one Con save to keep the concentration spells up when damage occurs.

I use this with NPC by allowing clerics to keep Shield of Faith up and still cast Bane or Spirit Guardians. The PCs use this with Hex and Darkness. My sorcerous PC hasn't taken advantage of the house rule.

 

[clearstream]

Now that we've had a few years playing & play testing 5e, I want to revisit the question of concentrating on multiple spells at once. I understand that there are probably a good lot of you that are cool with the RAW, and think that there is no possible way to concentrate on more than one spell at a time without breaking the game. If this is you, I respectfully suggest that this isn't the thread for you. This thread is for people open to considering how it could be done.

That being said, I agree that straight up allowing this sort of thing would break the game. However, I think that only invites inquiry into how it could be balanced. For the purpose of this discussion, I'll use "MSC" as an abbreviation for Multiple Spell Concentration. I'll start with some questions. I'm sure there are other good questions that will help flesh out the concept as time goes on.

1. Should it be a Class Feature, Spellcasting Rule, or Feat?
2. Is MSC something you can do all the time (like normal concentration), or would it be better to require the caster spend his action to concentrate on the additional spell(s)?
3. What are the side effects of MSC?
4. How would attributes and levels affect MSC?

--

1. I could see MSC getting rather cumbersome with additional conditions, so I'd rather keep the answer to the first question simple. I think it would be useful to try to make it an amendment to the Spellcasting Rules for concentration in the PHB. That way, all casters could have access to trying out their various unique builds. Making it a Class Feature is my second choice as I don't think that anyone who can cast spells should be able to. But, I think that adding side effects would provide enough drawbacks to dissuade certain builds.
2. By RAW, concentration is something you can do while going about your business. In order to balance the mental effort required to concentrate on two things at once, a pc could choose to give up their action on their turn in order to focus on more than one spell. Or, perhaps he must even forego any action, bonus action, reaction, or movement depending on the complexity of the spells on which he's attempting to concentrate. In my mind, it would be simpler to give the pc penalties to various mental abilities, AC, and/ or movement.
3. As for side effects, that would depend on the answer to the previous question.
   1. If the we look at giving up an action, then, factors that would affect how many phases of the turn are given up would be spell level and how many spells are taking up your concentration. Again, for simplicity's sake, the pc should give up his action for each round he maintains concentration on the additional spell. Perhaps even require a saving throw at the beginning of each turn to determine whether the pc maintains concentration.
   2. If we consider allowing the pc to concentrate and not give up any of his actions, we might look adapt the penalty structure for Cover/ Concealment. For a second low level spell or cantrip, the pc suffers a -2 to all mental skills and ac. For a second spell of equal level, -5 penalty. That sort of rule would be more useful for out of combat situations. Yeah, your human wizard can concentrate on Mage Armour and Darkvision. But, while his mind is occupied with that, he misses the kobold hidden in the crevice to the right.
4. I think that the attribute and proficiency bonuses should offset the penalties without any additional calculations. It would be cool to come up with some progression table. But, again simplicity.

---

Anyway, those are most of my thoughts on the topic. What other tweaks would be useful? I've looked into the UA Mystic. I can see some features there that might work.

One option that has worked well for me in the past is introduce the new rule in an item with charges. Each charge gives 24 hours of MSC.

Then if it works out, bring it in as a world rule. If it doesn't, the item eventually runs out of charges and leaves the campaign.

 

[phantomK9]

I have made a house rule for my game that anyone can cast and maintain multiple concentration spells with the following rules.

1. You must make a concentration check to maintain with DC = 10 + total levels of all spells. Fail and all fail.
2. At the end of a round in which you maintain MCS, you take one level of Exhaustion for each spell beyond the first.

Works pretty well.
Only one in the game so far to make use of it has been the Sorcerer and he is so adverse to taking Exhaustion levels that he saved using it for a fight against an adult blue dragon. He took about 2 or three levels of Exhaustion before willingly dropping one of the spells.

 

[DEFCON 1]

I don't think it should be a character-specific mechanic at all. So no class feature, no ability, no feat, none of that.

To my mind it's not a matter of restricting *A* character from concentrating on multiple things... it's restricting *the party* from having too many concentration effects going at one time. Because every additional spellcaster you have in a party exponentially expands the number of concentration buff spells and the like to be found across the PCs.

The real thing *I* would want to restrict is the total number of concentration spells the party can have going at any one time. Probably something like 3. No more than 3 concentration spells can be active in the group at any one time.

If you have a table of three players, one of which is a spellcaster and the other two are martial... having that ONE character concentrate on three different spells is not going to be that much of an issue. No more an issue that having a party of six characters, three of which are spellcasters, each of whom can only have one concentration spell active at a time. In both cases there are three different buff spells that can be active around the group.

The issue you'll run into if you make your rule about allowing a single PC to concentrate on more than one spell is when your party expands in size and you start getting more and more spellcasters. Suddenly, you find yourself running a group of eight players, six of which are casters of some type, and each of them takes whatever feature that allows for multiple concentration spells. Now you end up with like 10 to 12 buff spells active every combat because they can.

THAT'S what'll bite you in the ass. Not the one single caster PC in the group who is currently Blurred and wants to give Flying to their fighter, and then toss a Web. That lone caster can handle those three active spells. But woe be to you when you find your party with 9 or more buffs all running simultaneously in your party of 7+.

 

[schnee]

I've seen a few good suggestions, but to echo:

Restrict the spell level of the simultaneous castings to be low. 'Combined spell levels must be below the max spell level you can cast, so if you can cast 3rd level spells, you can hold two 1st-level spells max.' sounds good at first blush.

I'd also consider 'cannot cast any other spells, reaction or 1-action, while Concentrating on more than one spell'. So they lose Counterspelling and Absorb Elements, for example, while doing it.

I'd also say Concentration checks mean they roll once each for spell they have going, and if they miss one of those rolls, they lose them all.

 

[cthulhu42]

Isn't being able to concentrate on more than one spell an ability that sorcerers already have via Twin Spell? I feel like expanding that ability to other classes would give players one less reason to play a sorc.

That said, I don't think letting MSC in your game will break the world. There was a time in D&D when a wizard would have half a dozen of what 5E calls concentration spells going on most of the time. We somehow figured it out. I think it's just a matter of what you want to put up with as a DM.

There's a lot of good ideas here. I'd say give a few of them a test drive. The worst that can happen is you have to pull the plug on it if it doesn't work out.

 

[Wiseblood]

There are some pretty good ideas here but I would not allow MSC. Spells are powerful enough and spells/spellcasting fiddly enough that it is too much to bother with. Having flying and invisibility at the same time is undoubtedly more powerful than a 2nd level slot and a 3rd level slot put together.

 

[Thurmas]

I think that the concentration rules as they are pretty good. The thing I would change is that some of the spells themselves that require concentration shouldn't. They went a little overboard when they assigned concentration. Most spells already have a pretty short duration. But there are a number spells, mostly ones with physical changes, that I think could drop concentration. At the end of the spell duration, they simply disintegrate or revert to their original form. Just a handful of examples:


Spells that create physical things that don't change after creation:
Wall of Stone
Ensnaring Strike
Fog Cloud
Spike Growth
Earthbind
Stinking Cloud

Spells that physically alter someone:
Stone Skin
Alter Self
Barkskin
Enlarge/Reduce


I'm sure there are plenty of other examples. None of these spells have any thing that changes about them after you cast. To me, the requirement for concentration should mean it has an ongoing effect that you can change or influence, or if it is an ongoing effect that you on inflicting on an unwilling creature.