D&D 5E Altered (Slightly) Concentration Mechanic for review.

[DND_Reborn]

Hello, fellow tweakers! (Boy, that doesn't quite sound good, does it?)

After participating in the threads lately about concentration for spells and discussing it, I have devised my (latest) homebrew mechanic for concentration.

First, here are the threads for anyone who wants to go through them (and hasn't already):

D&D 5E - Homebrew: Removing Concentration From The Less Popular Spells

So in another thread on concentration here I said that I like concentration as a mechanic but it is too liberally attached to spells. There are a number of spells that just aren't competitive enough to see play and in many cases concentration is what is really holding them back. So the purpose...

www.enworld.org

D&D 5E - 5 Years in: Concentration

Lately, I've been growing frustrated with the Concentration mechanics in spells. I think it might be applied a little too much across the spells (I just realized, today, that Protection from Energy is concentration, but Protection from Poison isn't). I tend to not really bother with...

www.enworld.org

Here is the full description which replaces Concentration in the PHB, p. 203-204

Concentration
Some spells require you to maintain concentration in order to keep their magic active. If you lose concentration, such a spell ends.

If a spell must be maintained with concentration, that fact appears in its Duration entry, and the spell specifies how long you can concentrate on it. You can end concentration at any time (no action required).

Normal activity, such as moving and attacking, doesn’t interfere with concentration. The following factors can break concentration:

• Casting another spell that requires concentration. (This section is removed.)
• Multiple Concentration Spells. You can maintain concentration on more than one spell if you choose. When you cast each additional concentration spell, you must make a Concentration check for each spell you are currently concentrating on as well as the one you are casting. If you fail the check, you lose concentration on all spells you have active, including the one you are casting.
• Taking damage. Whenever you take damage while you are concentrating on a spell, you must make a Concentration check to maintain your concentration. If you take damage from multiple sources, such as an arrow and a dragon’s breath, you make a separate check for each source of damage. If you are concentrating on multiple spells, you must make a separate check for each spell. If the damage source is a critical hit or a failed save, the check is made with disadvantage.
• Being incapacitated or killed. You lose concentration on a spell if you are incapacitated or if you die.

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 Concentration check to maintain concentration on a spell.

You make a Concentration check using your spellcasting modifier. The DC is equal to 15 plus half of the spell level (round down) for the spell on which you are concentrating.

EDIT: So far one of the big comments has been about disadvantage on a critical hit or failed save. This is still something I am find a better way of doing. My intent is that a high-damage source should impose a penalty. I don't want it to be a calculation on the DC, but maybe something like "If the damage exceeds 10 + your spellcasting modifier, the check is made with disadvantage." would be better?

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So, that's it. War Caster still works the same (granting advantage) and is really good for casters who fear criticals and failed spell saves for damage since those will trigger disadvantage on the checks otherwise. But, this removes the need for Resilient and you don't have a bunch of casters running around with great poison saves and such.

Here is a table showing some sample likelihoods of failure given the spell level, character level, and ability score modifier.

Overall, I like this because it reflects that a higher-level caster will be better able to maintain concentration on lower-level spells. Critical hits and failed saves, which tend to yield very high damage, make the checks harder by imposing disadvantage, which I also feel is fitting. It also allows higher-level casters the ability to cast multiple low-level concentration spells, with the understanding that there is always a risk (however small) that is being taken.

Any questions, concerns, comments, or threats???

Thanks for reading!

 

[Chryssis]

Fair warning, I haven't read the previous threads to see arguments for or against any of the proposed changes, which I assume was already discussed to exhaustion, however, my two points of concern would be.

1. my assumption is that the 50%+ difficulty increase of the conc check is to compensate for the ability to concentrate on multiple spells. This is fine if you are concentrating on more than one, however is a pretty steep penalty if you are only concentrating on one spell.

2. increased difficulty from a failed save - this worries me in that it makes any damage dealing cantrip based on a save into a super mage killer, cast sacred flame, poof there goes all their concentrations.

 

[Khelon Testudo]

How about:

"If the damage source is a critical hit or a failed save against a spell that does half damage on a save, the check is made with disadvantage. "

 

[Charlaquin]

This looks to me like it would slow down play a lot with so many extra rolls. I would say rather than having to roll a concentration check for every spell you’re concentrating on, it would be better to increase the DC, maybe by +2 or +5, per spell beyond the first. Then if you fail, you lose concentration on all of them. Keep the concentration check for casting a concentration spell while concentrating.

 

[Olrox17]

Obviously, it’s a more complicated system than the default one, but I’d say that’s intentional.
Disconnecting concentration saves and constitution saves makes sorcerers a little less appealing mechanically. Getting con saves right off the bat was one of their draws.

Overall, this system could work, but it would require extensive playtesting at low, mid, and high levels.

 

[Horwath]

Having disadvantage on crit is double dipping on attempt to fail the check.

You already have double the DC from double damage. No need to make it worse.

Or keep it simple;

you can concentrate on 2 spells. Their combined level must be one level lower that your highest possible level.
you can concentrate on 3 spells. Their combined level must be two levels lower that your highest possible level.

so 5th level caster can concentrate on two level 1 spells,
9th level caster can concentrate on 3 level 1 spells,

 

[DND_Reborn]

Fair warning, I haven't read the previous threads to see arguments for or against any of the proposed changes, which I assume was already discussed to exhaustion, however, my two points of concern would be.

1. my assumption is that the 50%+ difficulty increase of the conc check is to compensate for the ability to concentrate on multiple spells. This is fine if you are concentrating on more than one, however is a pretty steep penalty if you are only concentrating on one spell.

No, the DC 15 bump is because the check is now a spellcasting check and not a CON save. Most casters don't have proficiency in CON saves and generally +3 to +5 CON modifiers, but all casters are proficient in their spellcasting and have +3 to +5 ability in their spell casting. So, instead of normally a +1 or +2 at many levels, the modifier is +5 to +11.

In general, if a caster is attempting their highest level spell, their chance for failing a check should be a bit under 50%.

2. increased difficulty from a failed save - this worries me in that it makes any damage dealing cantrip based on a save into a super mage killer, cast sacred flame, poof there goes all their concentrations.

Yeah, the intent was correct and I'll reword the OP to reflect it better. The idea was if the damage done is high (typically from a critical hit or failed save), the check should be with disadvantage. Originally, it was if the damage exceeded the DC of the check, it was at disadvantage. But, then I realized that lower levels spells were more likely to have disadvantage from a big damage source--and that didn't make sense.

How about: If the damage exceeds 10 + your spellcasting modifier, the check is made with disadvantage.

How about:

"If the damage source is a critical hit or a failed save against a spell that does half damage on a save, the check is made with disadvantage. "

That would also handle the cantrip killer-effect and was pretty much what I was going for. What do you think about the bolded option above?

This looks to me like it would slow down play a lot with so many extra rolls. I would say rather than having to roll a concentration check for every spell you’re concentrating on, it would be better to increase the DC, maybe by +2 or +5, per spell beyond the first. Then if you fail, you lose concentration on all of them. Keep the concentration check for casting a concentration spell while concentrating.

We'll play test it as is, and if we see a slow down then going with a flat DC increase might be the best way. I'd have to run some numbers to find out what a good flat increase would be, but it is a good idea.

Having disadvantage on crit is double dipping on attempt to fail the check.

You already have double the DC from double damage. No need to make it worse.

Or keep it simple;

you can concentrate on 2 spells. Their combined level must be one level lower that your highest possible level.
you can concentrate on 3 spells. Their combined level must be two levels lower that your highest possible level.

so 5th level caster can concentrate on two level 1 spells,
9th level caster can concentrate on 3 level 1 spells,

How is this double-dipping? The DC is based on the spell level, not damage. Disadvantage is only then imposed on a critical hit/failed save.

Keeping it simple is always a good thing, but I don't want it automatic. That's why I am making a concentration check required whenever you attempt to concentrate on more than one spell.