D&D 5E Balancing a Homebrew AoE Stun Spell

Esker · Feb 26, 2019

I'd like to homebrew a 3rd level "God Wizard" counterpart to fireball: a non-concentration AoE that debuffs instead of doing damage. I am thinking something along the lines of a "psychic blast" whose mechanics are something like: "Each creature in a X radius from a point you can see in range must make an INT save. A creature with an intelligence of 2 or lower can't be affected by this spell. On a failure the creature is stunned until the beginning of your next turn. If a creature takes damage they can repeat the save, ending the effect for that creature on a success."

Ways this is stronger than hypnotic pattern:
(a) not concentration
(b) stunned vs incapacitated
(c) INT save vs WIS save
(d) condition grants a save on damage instead of being automatically broken
(e) can be used on creatures immune to charm

Ways this is weaker than hypnotic pattern:
(a) only lasts one round, making it more of a damage amplification and prevention spell than a "divide-and-conquer" spell

Compare to fireball, it is stronger in that
(a) It targets INT vs DEX
(b) It causes missed turns, thus preventing potentially a lot of damage
(c) It is good against arbitrarily high CR enemies

but weaker in that
(a) It would be hard for the damage amplification afforded by one round of stunned to match 8d6 per creature (Yes, you can cast this to set up another caster's fireball causing auto-fail on the save, but just casting two fireballs does the same damage in the absolute worst case. You can also use it to cause faerie fire to auto-succeed, but this would be pretty inefficient too.)
(b) It doesn't really facilitate clearing mooks, since mooks are usually easy to hit anyway and people still have to spend their following turns attacking the mooks
(c) It does nothing on a save

Compare also to the monk's stunning strike, which costs less (1 ki point << 3rd level spell slot), doesn't use an action, and lets the monk benefit from the condition on their next turn; but targets CON and only affects one creature. Of course I know many people think stunning strike is OP already so maybe that's not such a useful comparison.

Compare also to synaptic static which also targets INT and also doesn't require concentration. It is 5th level and has a weaker debuff, but does 8d6 psychic damage and the debuff lasts until they save (rare for a non-concentration spell).

Since hypnotic pattern is the strongest 3rd level combat spell in most contexts, I think this is on balance probably a bit OP, as most homebrew ideas are in first draft.

So what do you think? Is there a radius greater than zero at which this spell is balanced? If so, what radius? If not, what would you change to keep it 3rd level?

dregntael · Feb 26, 2019

Seems like an interesting concept. However Fireball is intentionally overpowered so it is not a very good point of comparison. One thing to consider (and potential balancing effect) is whether it also affects allies -- I would say it should. Overall I would say this spell would be powerful but not too powerful - but only playtesting it can really tell.

Blue · Feb 26, 2019

5e is very, VERY sparse on non-concentration debuffs. It's an intentional part of the design philosophy. To make one, assume that's worth about 3-4 spell levels of change right there.

So If you want something like hypnotic pattern (3rd) without concentration, it's probably 6th to 7th level.

You can not have stun (serious debuff), area of effect, and 3rd level any more then you could have Wish, 3rd level.

You mention a monk's stunning strike. It's gained at 5th level and uses up a limited resource - it's a good guide for what a 3rd level spell (gained at 5th, limited resource) should do - single target, requires a successful attack roll, and then the target gets a CON save, for a single round of stun.

OB1 · Feb 26, 2019

I like the idea of this as a kind of flash-bang grenade. Taking from the 2nd level blindness/deafness spell, how about this?
FlashBang
4th level
Instantaneous
Range 90 feet
Radius 20 feet
A blinding light and loud bang erupt at a point of your choosing in range. All creatures in the radius of the blast make a Con saving throw. On a success, they are blinded and deafened until the end of their next turn, on a failure they are also stunned until the end of their next turn.

Esker · Feb 27, 2019

dregntael said:
Fireball is intentionally overpowered so it is not a very good point of comparison. One thing to consider (and potential balancing effect) is whether it also affects allies -- I would say it should.

And yet Fireball is not as good as Hypnotic Pattern if you have to choose between them, so maybe that's an even worse point of comparison (well, they have very different roles so depends on what else you have to do with concentration, of course). But one reason I'd like to homebrew a spell like this is to add some more variety to an arcane-caster-heavy party without people feeling like they are missing out on the obvious best spells at the level.

Definitely think it should affect allies. Thinking it ought to have a fairly small area and range. Maybe 5' radius sphere or 10' cube within 30' or something.

Esker · Feb 27, 2019

Blue said:
5e is very, VERY sparse on non-concentration debuffs. It's an intentional part of the design philosophy. To make one, assume that's worth about 3-4 spell levels of change right there.
...

You can not have stun (serious debuff), area of effect, and 3rd level any more then you could have Wish, 3rd level.

You mention a monk's stunning strike. It's gained at 5th level and uses up a limited resource - it's a good guide for what a 3rd level spell (gained at 5th, limited resource) should do - single target, requires a successful attack roll, and then the target gets a CON save, for a single round of stun.

Curious what your point of comparison is for saying that non-concentration is worth 3-4 spell levels. Wall of force (5th level, concentration) vs forcecage (7th level, non-concentration) is maybe a reasonable comparison; two level separation there, but forcecage lasts an hour (not saying an hour vs 10 minutes is an important difference, just that it's not one round vs some geometric distribution depending on their save modifier). Fire Shield is one level above Protection From Energy. It adds a little bit of damage on a hit, but has less versatility. I would consider Fire Shield to be pretty good and Protection From Energy to be pretty bad, but still.

The 4-level gap that comes to mind is Suggestion vs Mass Suggestion. Not only do you drop concentration, you get to affect twelve creatures and get three times the duration.

Anyway, not saying this spell isn't too strong, but 3-4 levels seems like an overstatement. I certainly wouldn't spend my 6th level slot on this.

Blue · Feb 27, 2019

Esker said:
Curious what your point of comparison is for saying that non-concentration is worth 3-4 spell levels. Wall of force (5th level, concentration) vs forcecage (7th level, non-concentration) is maybe a reasonable comparison; two level separation there, but forcecage lasts an hour (not saying an hour vs 10 minutes is an important difference, just that it's not one round vs some geometric distribution depending on their save modifier).

That's a decent example of only 2 level difference. You know, I can see 2 as the lower end. Bestow Curse also is 3rd level with concentration, but upcast to 5th level doesn't need it anymore. So let's go 2-3 levels above.

So the debuff power of a 1st level debuff with concentration would be around a 3rd-4th level spell.

So a 3rd level non-concentration spells might be like Tasha's Hideous Laughter. Single target incapacitation, saves every round plus additional saves with advantage every time it takes damage. Probably lasts more than 1 minute base.

Esker said:
Fire Shield is one level above vProtection From Energy. It adds a little bit of damage on a hit, but has less versatility. I would consider Fire Shield to be pretty good and Protection From Energy to be pretty bad, but still.

However, we're talking debuffs. Defenses have their own logic; there are a more spells that increase your survivability without concentration.

Esker said:
Anyway, not saying this spell isn't too strong, but 3-4 levels seems like an overstatement. I certainly wouldn't spend my 6th level slot on this

Really? Power Word Stun is an 8th level spell for a single target stun, only works of targets with 150 HPs or less, and gives a save every round. The spell you wouldn't "certainly wouldn't spend my 6th level slot on" will likely stun for more creature-rounds (since it can catch many), has no HP limit, and is two levels lower.

As a matter of fact, the lowest level stunning spells I could find in the PHB are Divine Word (30 HPs or less only) and Symbol (1 min casting, 1000gp components, non-mobile), both at 7th but with much harsher conditions on use. You may need to re-calibrate on how powerful a spell that grants the stun condition without concentration is considered in 5e by the designers. And then bump it up to make it multi-target.

Esker · Feb 27, 2019

Let's think about the monk comparison a bit more, since there aren't many other things that cause the stunned condition. I disagree that something that costs one ki point and piggybacks on an attack is a good reference point for a 3rd level spell. A 5th level monk has 5 ki points, which refresh on a short rest. A 5th level caster has two 3rd level spell slots per long rest. Even if you never get a short rest the monk gets way more use out of single-ki abilities; if you get two, they can use them 15 times a day vs 2. If the stun spell only affected a single creature -- even if it lasted until the end of your next turn instead of the start -- it would be much weaker than stunning strike, simply because it's a 3rd level spell. Yes, CON is a harder target than INT, and yes you have to hit with an attack first to attempt stunning strike, but you don't have to choose to spend the point until after you hit so that doesn't seem like a major factor; especially considering a 5th level monk gets at least two melee weapon attack attempts per turn. Usually one of those will hit, so you're not likely to be unable to attempt a stun on the turn you want.

rczarnec · Feb 27, 2019

Another point of comparison is Psychic Scream which is an AOE stun with some damage and is not concentration. It is a 9th level spell.

The Crimson Binome · Feb 27, 2019

I won't comment on whether it's balanced, because you're using synaptic static as a reference point, but I will say that the part about extra saving throws when attacked is very fiddly for a spell that only lasts one round. I would be more comfortable raising the level to 4, and getting rid of that caveat.

It does seem a bit powerful, though, since its effect scales automatically with the power of your opponent. I mean, that's true of all status conditions in 5E, but this spell looks like it was specially built to exploit that flaw in the system.